vmacair V900135 Underhood70 Air Compressors Instruction Manual

vmacair V900135 Underhood70 Air Compressors

Product Information

Specifications

• Product: 70 UNDERHOOD TM AIR COMPRESSORS
• Installation Manual: V900135
• Website: www.vmacair.com

Table of Contents

• VMAC – Vehicle Mounted Air Compressors
• VMAC Technical Support: 888-241-2289
• VMAC Knowledge Base: www.kb.vmacair.com

Additional Application Information

The product is suitable for diesel engines and comes with a throttle control feature.

Registered Trademarks
All trademarks mentioned in this manual are the property of their respective owners. VMAC’s use of manufacturers’ trademarks in this manual is for identification purposes only and does not imply any affiliation or endorsement of said companies.

Important Information

Notice: Printed in Canada

Product Usage Instructions

Safety

Important Safety Notice
Only follow proven service procedures recommended in this manual. If you deviate from the provided instructions, ensure that safety is not compromised and there are no adverse effects on the equipment’s operational safety or performance. VMAC will not be held responsible for any liability, consequential damages, injuries, loss, or damage caused by failure to adhere to the procedures or standard safety practices.

Safety Messages
This manual contains various warnings, cautions, and notices that must be observed to reduce the risk of personal injury, equipment damage, or rendering it unsafe during installation, service, or repair. Pay attention to the following symbols:

Attention Symbol:
This symbol indicates important safety precautions. Your personal safety is involved. Read the accompanying message and be aware of the possibility of personal injury or death.

Equipment Damage Symbol:
This symbol indicates instructions on a specific procedure that, if not followed, may damage or reduce the useful life of the compressor or other equipment.

Additional Instructions Symbol: This symbol is used to call attention to additional instructions or special emphasis on a specific procedure.

Warranty

For complete warranty information, including both VMAC Standard Warranty (Limited) and VMAC Lifetime Warranty (Limited) requirements, please refer to our current published warranty located at: www.vmacair.com/warranty

Frequently Asked Questions (FAQ)

Q: Where can I find technical support for VMAC products?
A: You can contact VMAC Technical Support at 888-241-2289 or visit their Knowledge Base at www.kb.vmacair.com

70 UNDERHOOD TM AIR COMPRESSORS
Installation Manual for VMAC System
V900135
2019+ Chevrolet 4500 ­ 6500 Chassis Cab 2019+ International CV515 Chassis Cab 6.6 L Duramax Diesel
www.vmacair.com

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

1

VMAC Knowledge Base: www.kb.vmacair.com

Document: 1930390 Changes and Revisions

Revision

Revision Details

C

ECN: 20-066 Update stud torque value

D

ECN: 23-153 Update Idler info

Revised by
MSP MSP

Checked by Eng.
Tech. Qual. Mech. Elec. MRH N/A MSP N/A KRM N/A MSP LPH

Implemented
11 Mar 2020 10 Jul. 2023

Additional Application Information
· 2019+ Chevrolet 4500 ­ 6500 Chassis Cab equipped with 6.6 L Duramax
Diesel.
· 2019+ International CV515 Chassis Cab equipped with 6.6 L Duramax Diesel. · Note that this VMAC system may be equipped with either a digital or analog
throttle control.

Registered Trademarks

All trademarks mentioned in this manual are the property of their respective owners. VMAC’s use of manufacturers’ trademarks in this manual is for identification of the products only and does not imply any affiliation to, or endorsement of said companies.

Loctite®, Loctite® 242 and Loctite® 567 are registered trademarks of Henkel AG & Company KGaA. Eaton Aeroquip® is a registered trademark of EATON AEROQUIP INC. Chevrolet® and Duramax® are registered trademarks of General Motors Company LLC. International® is a registered trademark of NAVISTAR INTERNATIONAL CORPORATION.
Important Information
The information in this manual is intended for certified VMAC installers who have been trained in installation and service procedures and/or for anyone with mechanical trade certification who has the tools and equipment to properly and safely perform the installation or service. Do not attempt installation or service without the appropriate mechanical training, knowledge and experience. Follow all safety precautions. Any fabrication for correct fit in modified vehicles must follow industry standard “best practices”.

Notice
Copyright © 2021 VMAC Global Technology Inc. All Rights Reserved. These materials are provided by VMAC for informational purposes only, without representation or warranty of any kind, and VMAC shall not be liable for errors or omissions with respect to the materials. The only warranties for VMAC products and services are those set forth in the express warranty statements accompanying such products and services, if any, and nothing herein shall be construed as constituting an additional warranty. Printing or copying of any page in this document in whole or in part is only permitted for personal use. All other use, copying or reproduction in both print and electronic form of any part of this document without the written consent of VMAC is prohibited. The information contained herein may be changed without prior notice.
Printed in Canada

VMAC – Vehicle Mounted Air Compressors

2

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Safety

Important Safety Notice
The information contained in this manual is based on sound engineering principles, research, extensive field experience and technical information. Information is constantly changing with the addition of new models, assemblies, service techniques and running OEM changes. If a discrepancy is found in this manual, contact VMAC Technical Support prior to initiating or proceeding with installation, service or repair. Current information may clarify the issue. Anyone with knowledge of such discrepancies, who proceeds to perform service and repair, assumes all risks.
Only proven service procedures are recommended. Anyone who departs from the specific instructions provided in this manual must first ensure that their safety and that of others is not being compromised, and that there will be no adverse effects on the operational safety or performance of the equipment.
VMAC will not be held responsible for any liability, consequential damages, injuries, loss or damage to individuals or to equipment as a result of the failure of anyone to properly adhere to the procedures set out in this manual or standard safety practices.
Safety should be the first consideration when performing any service operations. If there are any questions concerning the procedures in this manual, or more information is required, please contact VMAC Technical Support prior to beginning work.
Safety Messages
This manual contains various warnings, cautions and notices that must be observed to reduce the risk of personal injury during installation, service or repair and the possibility that improper installation, service or repair may damage the equipment or render it unsafe.
This symbol is used to call attention to instructions concerning personal safety. Watch for this symbol; it points out important safety precautions, it means, “Attention, become alert! Your personal safety is involved”. Read the message that follows and be aware of the possibility of personal injury or death. As it is impossible to warn of every conceivable hazard, common sense and industry standard safety practices must be observed.
This symbol is used to call attention to instructions on a specific procedure that if not followed may damage or reduce the useful life of the compressor or other equipment.
This symbol is used to call attention to additional instructions or special emphasis on a specific procedure.

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

3

VMAC Knowledge Base: www.kb.vmacair.com

Warranty

VMAC Standard Warranty (Limited)
For complete warranty information, including both VMAC Standard Warranty (Limited) and VMAC Lifetime Warranty (Limited) requirements, please refer to our current published warranty located at: www.vmacair.com/warranty

If you do not have access to a computer, please contact us and we will be happy to send you our warranty.

VMAC’s warranty is subject to change without notice.

VMAC Lifetime Warranty (Limited)

A VMAC Lifetime Limited Warranty is offered

AIR INNOVATED

on the base air compressor only and only on

UNDERHOODTM, Hydraulic Driven, Transmission Mounted, Gas and Diesel Engine Driven Air

LIFETIME

Compressors, Multifunction Power Systems, and other products as defined by VMAC, provided that (i) the purchaser fully completes and submits a

WARRANTY
TRUST SERVICE VALUE

warranty registration form within 3 months of purchase, or 200 hours of operation,

whichever occurs first; (ii) services are completed in accordance with the Owner’s

Manual; (iii) proof of purchase of applicable service kits are made available to

VMAC upon request.

The VMAC Lifetime Warranty is applicable to new products shipped on or after 1 October, 2015.

Warranty Registration

The VMAC warranty registration form is located near the back of this manual. This warranty registration form must be completed and sent to VMAC at the time of installation for any subsequent warranty claim to be considered valid.

There are 4 ways the warranty can be registered with VMAC:

www.vmacair.com/warranty

warranty@vmacair.com
877-740-3202 VMAC – Vehicle Mounted Air Compressors 1333 Kipp Road, Nanaimo, BC, Canada V9X 1R3

VMAC – Vehicle Mounted Air Compressors

4

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

VMAC Warranty Claim Process
VMAC warranty work must be pre-authorized by VMAC. Claims are processed via our dealer network. If you are not a VMAC dealer, please select one to work with via our Dealer Locator: https://www.vmacair.com/dealer-locator/

1. Communicate with VMAC Technical Support at 1-888-241-2289 or tech@vmacair.com to help diagnose/troubleshoot the problem prior to repair. VMAC technical support will require the VMAC System ID, and hours on the compressor.
2. VMAC will provide direction for repair or replacement of the failed components.
3. If requested, failed parts must be returned to VMAC for evaluation.
4. Dealers may login to the VMAC website to view the “VMAC Labour Time Guide” (under “Agreements”) to see the allowable warranty labour times.
5. Warranty invoices must include the Service Ticket number, VMAC System ID#, hours on the compressor, and a detailed description of the work performed.
6. VMAC Warranty does not cover consequential damages, overtime charges, mileage, travel time, towing/recovery, cleaning or shop supplies.
7. Dealers submit warranty claims on behalf of the Vehicle Owner/End User affected by the defective part(s). The dealer ensures that all warranty credits are refunded back to the Vehicle Owner/End User who made the initial warranty claim.
   In order to qualify for Lifetime Warranty (Limited), the completed warranty registration form must be received by VMAC within 3 months of the buyer receiving the Product(s), or 200 hours of operation, whichever occurs first.
   If the completed warranty registration form has not been received by VMAC within 3 months of the buyer receiving the Product(s), or 200 hours of operation, the warranty period will be deemed to commence 30 days from the date of shipment from VMAC.
   Failure to follow the warranty claim process may result in denial of the warranty claim.
   VMAC Product Warranty Policies & Warranty Registration can be found on the VMAC website (see previous page for URL).

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

5

VMAC Knowledge Base: www.kb.vmacair.com

General Information

Optional Equipment Compatibility
While VMAC strives to design systems compatible with optional OEM equipment (such as running boards), it is impractical to develop systems that accommodate every OEM and aftermarket option or add-on. Whenever possible, VMAC endeavors to advise of compatibility issues in the “Additional Application Information” section of the manual. Even when specific optional equipment is determined by VMAC to be incompatible, it does not preclude the vehicle upfitter or end user from modifying the optional equipment to make it compatible with the installed VMAC system. VMAC does not warranty or accept responsibility or liability for the fitment, function or safety of any products modified in any way not expressly outlined in the installation manual.

Before Starting
Note and label all parts that are removed from the vehicle as many of the OEM parts will be reused during the installation of the VMAC system. Read this manual prior to beginning the installation to ensure familiarity with the components and how they will fit on the vehicle. Identify any variations from the application list such as vehicle model, engines, or optional equipment (e.g., dual alternator, active steering assist, etc.).
Open the package, unpack the components and identify them using the Illustrated Parts List (IPL) included in the Fastener Pack.

Hose Information
Depending on other installed equipment, it might be necessary to move the air/oil separation tank from its intended location. The hoses used in VMAC compressor systems have a specific inner liner that is compatible with VMAC compressor oil. Use of hoses other than those supplied or recommended by VMAC may cause compressor damage and may void your warranty. Please contact VMAC for replacement hoses and further information.

Ordering Parts
To order parts, contact a VMAC dealer. The dealer will ask for the VMAC serial number, part number, description and quantity. Locate the nearest dealer online at www.vmacair.com/dealer-locator or call 1-877-912-6605.

VMAC – Vehicle Mounted Air Compressors

6

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Special Tools Required

· None.
Torque Specifications
All fasteners must be torqued to specifications. Use manufacturers’ torque values for OEM fasteners.
The torque values supplied in Table 1 are intended for VMAC supplied components, or for use as a guide in the absence of a torque value provided by an OEM.

Apply Loctite 242 (blue) to all fasteners (except nylon lock nuts) unless otherwise stated.

Torque values are with Loctite applied unless otherwise specified.

Standard Grade 8 National Coarse Thread

Size (in)

1/4 5/16 3/8 7/16 1/2 9/16 5/8 3/4

Foot pounds (ft·lb) 9 18 35 55 80 110 170 280

Newton meter (N·m) 12 24 47 74 108 149 230 379

Standard Grade 8 National Fine Thread

Size (in)

3/8

7/16

1/2

5/8

3/4

Foot pounds (ft·lb)

40

60

90

180

320

Newton meter (N·m) 54

81

122

244

434

Size (mm)

Metric Class 10.9

M6

M8

M10 M12 M14 M16

Foot pounds (ft·lb) 4.5

19

41

69

104

174

Newton meter (N·m) 6

25

55

93

141

236

Table 1 — Torque Table

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

7

VMAC Knowledge Base: www.kb.vmacair.com

System Identification, Warranty Registration and Warning Labels
Preparation for installation is very important. Missing a step or an item can cause problems in the installation or damage to components.
Check off each item as it is completed so that no steps are
missed.
Review the contents of the system using the illustrated parts list to ensure all
components are present and in the correct quantity. If any components are missing, have the system ID ready and call VMAC Technical Support at 888-241-2289.
The VMAC warranty form must be completed and returned to VMAC at the time of installation for any subsequent warranty claim to be considered valid.
Complete the warranty form. The VMAC warranty form is located at the back of
this manual, as well as online at: www.vmacair.com/warranty
The System Identification Plate must be attached to the vehicle at the time of installation. This plate provides information that allows VMAC to assist with parts and repairs.
Locate a conspicuous area in the engine bay (where the tag will be easily
noticed) to install the System ID tag.
Mark and drill (×2) 7/64 in holes and secure the plate with the supplied self-
tapping screws (Figure 1).

Figure 1 — System Identification Plate

VMAC – Vehicle Mounted Air Compressors

8

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

As part of the installation process, ensure that the safety and operational
instruction decal is affixed in an obvious location so that it can be seen by vehicle operators. A good spot for this is usually on the inside of the door or on the panel underneath the steering wheel (Figure 2).

Figure 2 — Operating Instruction label
To alert any technicians that may service the vehicle, affix the servicing caution/
contact decal in a conspicuous area in the engine bay (where the decal will be easily noticed) (Figure 3).

Figure 3 — Advisory decal

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

9

VMAC Knowledge Base: www.kb.vmacair.com

Preparing for Installation
Ensure the VMAC Warranty Registration has been completed and the System Identification Plate and Operating Instruction Label are installed prior to proceeding (Please see page 8 for details).
To improve access while installing the system, park the vehicle with the wheels turned all of the way to the driver side.
Disconnect the negative terminal from the batteries. Drain the coolant into a clean container and set it aside for use later.
Ensure the hose is not damaged when removing the shrink cuffs.
Remove the lower radiator “hard line” (metal tube); retain all of the OEM clamps
(Figure 4).

Lower radiator hose

Cut shrink cuff

Radiator (for reference only

Remove “hard line”

Figure 4 — Remove lower radiator `Hard line”

Separate the lower radiator hose from the hard line; retain the lower radiator
hose and discard the hard line (Figure 4).

VMAC – Vehicle Mounted Air Compressors

10

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Using a grease pen, mark a line approximately 1/4 in past the curve on the 5/8
in OEM hose where it met the hard line. Cut the radiator hose in the marked location, ensuring the cut is square to the hose section (Figure 5).

Cut hose Figure 5 — Modify 5/8 in hose
Lay the curved section of the lower radiator hose flat on a bench. From the engine side of the hose, measure 1 in towards the center of the hose
and mark it with a grease pen (Figure 6). Radiator side
1 in

Figure 6 — Modify lower radiator hose

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

11

VMAC Knowledge Base: www.kb.vmacair.com

Cut the radiator hose in the marked location, ensuring the cut is square to the
hose section; discard the 1 in section of hose (Figure 6 on page 11).
Cut 1 in from the front edge of each of the OEM lower radiator braces (Figure 7).
Cut 1 in from braces
Figure 7 — Modify lower radiator support braces
Remove the tension from the fan drive belt. Remove and discard the front OEM pulley but retain the (×3) OEM crank pulley
fasteners (Figure 8).

Figure 8 — Remove front OEM pulley

VMAC – Vehicle Mounted Air Compressors

12

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Installing the Crank Pulley and Oil Cooler
Vehicles manufactured after 20 March 2023 have a different OEM belt line from earlier model years. This VMAC kit includes an idler, spacers, and fastener that replace the OEM assembly used on post 20 March 2023 vehicles. For vehicles manufactured prior to 20 March 2023, discard the idler, spacers, and fastener as they are not used.
Identify which belt line the vehicle is equipped with (Figure 9).

Pre 20 March 2023 build

Post 20 March 2023 build

Figure 9 — Identify belt line

Vehicles manufactured prior to 20 March 2023: skip to “Installing the Crank
Pulley” on page 14.

Vehicles Manufactured After 20 March 2023
Remove the belt. Remove and discard the idler and fastener (Figure 10).

Remove idler

Figure 10 — Remove OEM idler

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

13

VMAC Knowledge Base: www.kb.vmacair.com

Install the supplied idler spacer, idler, and idler adaptor (Figure 11).
Idler adaptor
Idler spacer
Figure 11 — Install idler assembly Installing the Crank Pulley
Scrape any clear coat or rust from the inside front face of the crank pulley hub
to ensure the VMAC crank pulley will sit squarely against it
Using the (×3) OEM crank pulley fasteners, install the VMAC crank pulley
(Figure 12).

Figure 12 — Install VMAC crank pulley

VMAC – Vehicle Mounted Air Compressors

14

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Tension the fan drive belt. Install the supplied coupler with spigot using the supplied gear clamp (Figure 13).
Install coupler
Figure 13 — Install coupler
Using the OEM spring clamp, connect the modified 5/8 in hose to the spigot on
the coupler (Figure 14).

Figure 14 — Install 5/8 in hose

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

15

VMAC Knowledge Base: www.kb.vmacair.com

Using one of the supplied gear clamps, install the modified lower radiator hose
onto the coupler (install the hose with the unmodified end of the hose toward the coupler) (Figure 15).

Modified end
Figure 15 — Install modified hose
Using one of the supplied gear clamps, install the supplied 2 in radiator hose
onto the radiator (Figure 16).

Install supplied radiator hose

Figure 16 — Install radiator hose

VMAC – Vehicle Mounted Air Compressors

16

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Using the clamp retained earlier, install the oil cooler onto the lower radiator
hose (Figure 17).

Figure 17 — Install oil cooler
Using one of the supplied gear clamps, connect the modified lower radiator
hose to the oil cooler (Figure 18).

Figure 18 — Install oil cooler

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

17

VMAC Knowledge Base: www.kb.vmacair.com

Using the supplied M6 fasteners and lock nuts, secure the oil cooler to the
modified radiator brace (Figure 19).

Figure 19 — Install oil cooler
Remove the coolant drain back hose running between the degas bottle and the
hard line, retain the spring clamps (Figure 20).
Remove coolant drain back hose
Coolant drain back “hard line”

Figure 20 — Remove coolant drain back hose

VMAC – Vehicle Mounted Air Compressors

18

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

The coolant drain back “hard line” can either be removed and discarded or left in place (provided it remains securely attached to the engine).
Using a grease pen, mark a line approximately 3 in past the curve on the 5/8 in
OEM coolant drain back hose. Cut the hose in the marked location, ensuring the cut is square to the hose section (Figure 21).
To “hard line”
3 in
Figure 21 — Modify coolant drain back hose
Using the retained spring clamp, install the modified coolant drain back hose
onto the degas bottle (Figure 22).

Figure 22 — Install coolant drain back hose

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

19

VMAC Knowledge Base: www.kb.vmacair.com

Using the remaining spring clamp, install the hose barb onto the modified
coolant drain back hose (Figure 23).

Figure 23 — Install hose barb
Using one of the supplied gear clamps, connect the supplied heater hose to the
hose barb on the coolant drain back hose.
Route the hose down toward the VMAC oil cooler, securing it as necessary with
rubber coated P-clips or cable ties.
Using one of the supplied gear clamps, connect the heater hose to the barb on
the oil cooler.
Fill the coolant system with the coolant that was retained earlier.

VMAC – Vehicle Mounted Air Compressors

20

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Installing the Air Oil Separator Tank (AOST)
Dependent upon other installed equipment, it may be necessary to move the AOST from its intended location. The hoses used in VMAC compressor systems have a specific inner liner that is compatible with VMAC compressor oil. Use of hoses other than those supplied or recommended by VMAC may cause compressor damage and may void the warranty.
The AOST must be level for proper air/oil separation, and to ensure that the oil level will display accurately in the sight glass.
Apply Loctite 242 (blue) to all fasteners.
Installing the AOST
The AOST will mount on the driver side, to the rear of the battery box step (Figure 24).

Front of vehicle Figure 24 — AOST installed

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

21

VMAC Knowledge Base: www.kb.vmacair.com

Using the (×3) M6 × 1 × 25 fasteners and (×3) M6 nuts, install the “Outboard”
AOST mounting bracket onto the body mount located to the rear of the battery box and step (Figure 25).

Front of vehicle

(×3) M6 × 1 × 25 fasteners

(×3) M6 nuts

Battery box
Figure 25 — Installing the AOST
Using the (×2) M12 × 1.75 × 25 fasteners and (×2) M12 nuts, install the “Inboard”
AOST mounting bracket to the frame cross member (adjacent to the body mount that the “Outboard” AOST mounting bracket is installed on) (Figure 26).

“Outboard” AOST mounting bracket (For reference only)

Front of vehicle
(×2) M12 × 1.75 × 25 fasteners

(×2) M12 nuts

Figure 26 — Installing the AOST

VMAC – Vehicle Mounted Air Compressors

22

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Remove the AOST clamp pinch bolts (Figure 27).
(×2) Tank clamp lock nut

(×4) M8 nut

(×2) Pinch bolt
(×4) M8 × 1.25 × 20 fastener
Figure 27 — Install AOST (AOST not shown for clarity)
Install the tank clamps over the front of the tank and slide them toward the
centre of the tank. Install the tank onto the tank mounts, leaving the fasteners finger tight (Figure 27):
Adjust the tank in the straps, the front of the AOST should protrude
approximately 5 in ­ 6 in past the tank strap.
Apply loctite 242 (blue) to the (×2) 3 in × 1/4 in pinch bolts and install them
into the mounting clamps.
Rotate the tank so that the directional arrow on the blowdown cap, at the rear
of the tank, is pointing upward.
AOST orientation is critical. The arrow on the blowdown cap at the rear of the tank must be pointing up to prevent compressor failure due to oil starvation, or oil in the discharge air.
Tighten the AOST mounting bolts.
VMAC recommends using a using smooth radius 90° hose crimp fitting at the AOST discharge for best performance and exhaust clearance

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

23

VMAC Knowledge Base: www.kb.vmacair.com

Installing the Main Bracket and Compressor

Apply Loctite 242 (blue) to all engine mounted fasteners.

In order to accommodate the VMAC main bracket, it may be necessary to deflect brackets supporting hoses and/or electrical harnesses. If bracket adjustment is required, ensure the OEM hoses/ harnesses are adequately protected from heat, vibration, and sharp or moving components.
Remove and discard the fasteners securing the power steering fluid reservoir to
the bracket.
Secure the power steering fluid reservoir upright and out of the way.
Remove the fan stator mount; retain the stator post but discard the bracket and
fastener (Figure 28).

Fan stator brace

Retain post

Discard bracket and fastener
Figure 28 — Remove fan stator mount
Install the fan stator post onto the VMAC main bracket (Figure 29).

Install post

Figure 29 — Install fan stator post

VMAC – Vehicle Mounted Air Compressors

24

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Remove the lower idler from the FEAD bracket assembly and set it aside (Figure 30).

Remove idler
Figure 30 — Remove lower idler
Remove and discard the fastener directly below the power steering pulley
(Figure 31). Power steering pulley

Remove fastener

Figure 31 — Remover OEM fastener

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

25

VMAC Knowledge Base: www.kb.vmacair.com

Thread the supplied stud into the extension post, leaving 3 1/2 in of the stud
exposed (Figure 32). 3 1/2 in
Figure 32 — Install extension post
Insert the roll pin into the extension post, followed by the idler fastener retained
earlier. Thread the idler fastener in until it locks against the roll pin (Figure 33).
Figure 33 — Install extension post
Install the stud into the engine, below the power steering pulley, and torque it
to 21 ft·lb (Figure 34).

Figure 34 — Install extension post

VMAC – Vehicle Mounted Air Compressors

26

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Remove and retain the idler fastener. Discard the roll pin. Torque the extension post to 21 ft·lb (Figure 35).
Remove fastener and roll pin
Torque extension post
Figure 35 — Install extension post
Using the supplied fasteners, install the main bracket onto the OEM AC bracket
(Figure 36).
(×2) M10 × 1.5 × 45

Modified M10 × 1.5 × 80

Figure 36 — Install main bracket (OEM drive belt not shown for clarity)

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

27

VMAC Knowledge Base: www.kb.vmacair.com

Using the supplied fasteners, install the FEAD bracket assembly (Figure 37).
(×2) M10 × 1.5 × 60
M10 × 1.5 × 150
M10 × 1.5 × 90 M10 × 1.5 × 60 Figure 37 — Install the FEAD bracket
Reinstall the lower idler onto the FEAD assembly bracket (Figure 38).

Figure 38 — Install idler
Torque the tensioner and all of the idlers to specification.

VMAC – Vehicle Mounted Air Compressors

28

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Mount the fan stator brace onto the relocated post (Figure 39).

Fan stator brace post

Fan stator brace

VMAC FEAD bracket assembly
Figure 39 — Mount fan stator brace
Install the fan harness extension, ensuring the plug and pins are firmly seated. Route the fan stator harness past the air conditioner pump and secure it to the
air conditioner pump fastener using the supplied P-clip and nut (Figure 40).

Figure 40 — Route fan stator harness

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

29

VMAC Knowledge Base: www.kb.vmacair.com

Route the fan stator harness around back of main bracket and connect it to the
OEM connector.
Apply the supplied protective loom on the OEM harness where it passes near
the rear of the compressor (Figure 41).
Apply protective loom

Figure 41 — Install loom
Install the compressor onto the VMAC main bracket; install the shortest fastener
in the front passenger side of the compressor (Figure 42). M8 × 1.25 × 110
(×3) M8 × 1.25 × 120

Figure 42 — Install compressor

VMAC – Vehicle Mounted Air Compressors

30

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Install and tension the VMAC FEAD belt (Figure 43).

Figure 43 — VMAC FEAD belt routing

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

31

VMAC Knowledge Base: www.kb.vmacair.com

Hose Requirements
Only attempt to shorten the supplied hose if there is access to the appropriate equipment. Do not attempt to cut the hose and splice it using hose clamps.
VMAC Compressor oil will degrade rubber lined hoses, use only hoses with an AQP elastomer type liner. Contact VMAC Technical Support at 1-888-241-2289 for further information.
The PTFE tubes and AQP elastomer lined hoses are specifically designed to work with VMAC compressor oil and at compressor operating temperatures.
Dependant upon the desired location of the AOST, the hose lengths provided with this system may not be ideal. VMAC suggests first trying to adjust the AOST within its mounts to take up any excess slack in the hoses. If this is not effective, the hoses can be shortened or replaced as necessary, or hose extenders can be used.
VMAC recommends shortening these hoses as a preferred alternative to coiling up and securing the excess. Shorter hose length will maximize system performance.
Avoid using 90° fittings wherever possible as they cause flow restrictions and negatively impact performance.
The following hoses are included with this compressor kit:
· 3/4 in × 93 in. · 1/2 in × 109 in. · 1/2 in × 42 in. · 1/4 in (PTFE tube) × 120 in. · 3/16 in (PTFE tube) × 120 in.
If longer hoses are required:
To order parts, contact a VMAC dealer. The dealer will ask for the VMAC serial number, part number, description and quantity. See page 6 for ordering information.
· Eaton Aeroquip hoses with an “AQP” type inner liner are required. · OTC fittings are required for the VMAC supplied hose. · Push-lock fittings are suitable if FC332 hose is used. · If Push-lock fittings are being used, do not use hose clamps as they will
damage the hose and cause leaks.

VMAC – Vehicle Mounted Air Compressors

32

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Connecting the Hoses

When routing hoses, ensure cap plugs are installed so that contaminants do not get in the line. Take care when routing hoses, as a hose failure may damage the compressor and/or cause injury.

All hoses, tubes and wires that are installed, rerouted or shifted during the installation must be secured so that they do not contact any hot, sharp or moving parts. Use rubber coated P-clips wherever possible. Follow the routing suggestions in this manual and cover all hoses with plastic loom.
Push-To-Connect Fittings (Figure 44)
Lubricate the tube and firmly push it into the fitting so that the tube fully seats
in the fitting.
Slide the collet out, away from the body of the fitting to lock the tubing in place.
Ensure the tube does not have any “play” to prevent the O-ring from wearing.

Cut the tube squarely, using only proper tubing cutters as side cutters
will deform the tube.

Slide the collet out once the tube is fully inserted

O-ring

Figure 44 — Push-to-connect fittings

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

33

VMAC Knowledge Base: www.kb.vmacair.com

Connect the straight fitting on the 3/4 in discharge hose to the fitting on the
back of the compressor.
From the compressor, route the hose down to the top of the frame rail and to
the inside of the cab mount (Figure 45).

Figure 45 — Connect discharge hose
From the cab mount, route the hose along the cab, then down to the AOST.
Secure the hose to the cab using the supplied P-clips and fasteners (Figure 46).
Supplied P-clips

Figure 46 — Connect discharge hose (Step / battery box removed for clarity)

VMAC – Vehicle Mounted Air Compressors

34

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Apply split loom to the 3/16 in and 1/4 in PTFE tubes. Connect the PTFE tubes to the push-to-connect fittings on the compressor. Route the PTFE tubes along the 3/4 in discharge hose to the frame rail. From the 3/4 in discharge hose, route the PTFE tubes along the OEM fuel lines
to the fuel filter.
From the fuel filter, route the PTFE tubes along the top of the AOST, and
connect them to the push-to-connect fittings in the blowdown cap.
Connect the 90° fitting on the shorter 1/2 in hose to the passenger side fitting
on the VMAC oil cooler.
Route the 1/2 in hose to the driver side of the vehicle, then up toward the OEM
wiring bundles (Figure 47).
Figure 47 — Connect compressor oil supply hose
From the OEM wire bundles, route the 1/2 in hose up to the compressor and
connect it to appropriate fitting (Figure 48).

Figure 48 — Connect compressor oil supply hose

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

35

VMAC Knowledge Base: www.kb.vmacair.com

Connect the 90° fitting on the longer 1/2 in hose to the driver side fitting of the
VMAC oil cooler.
Route the 1/2 in hose over the engine cross member, following the transmission
cooler lines, then down toward the bottom of the driver side frame rail (Figure 49).
Figure 49 — Connect compressor oil return hose
Continue to route the 1/2 in hose along the same path as the transmission
cooler lines, then loop the hose toward the AOST along the bottom of the battery box (Figure 50).

Figure 50 — Connect compressor oil return hose

VMAC – Vehicle Mounted Air Compressors

36

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Using the supplied 90 ° fitting, connect the 1/2 in hose to the fitting on the
AOST (Figure 51). Figure 51 — Connect compressor oil return hose

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

37

VMAC Knowledge Base: www.kb.vmacair.com

Adding Oil to the System
The VMAC supplied and approved compressor oil must be used in this system. Failure to use this special oil will result in damage to the compressor and will void warranty. Do not overfill the system. Overfilling the system with oil can flood the sight glass window and make the system appear empty.
Ensure the vehicle is parked on level ground. Remove the oil filter from the AOST and discard the cardboard warning tag. Apply a light film of compressor oil to the filter gasket and thread the filter onto
the AOST until the gasket makes contact. Tighten the filter an additional 3/4 to 1 turn after the gasket contacts the base.
Remove the fitting from the inlet (Figure 52).
Oil fill fitting

Figure 52 — Oil fill location
Using a funnel, fill the system with the supplied oil. When dry, the system will
take approximately 5 L (5.2 qt) of oil.
Allow a few minutes for the oil to drain into the AOST. Check the level at
the sight glass at the front of the AOST. Continue adding oil until the level is correct.
Replace the oil fill fitting and tighten.

VMAC – Vehicle Mounted Air Compressors

38

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Installing the Control Components
Best Practices
· To confirm a good ground, use an ohm meter to measure the resistance
between the ground point and the negative battery terminal. Resistance should be less than 1 .
· Route all wires to ensure they will not contact hot, sharp or moving parts
(including the park brake mechanism, steering column, and pedals).
· Before drilling any holes ensure there are no OEM wires, hoses, or
components that may be damaged.
· Do not use a test light to probe for power on vehicle circuits, the increased
current draw of the test light may damage components.
· VMAC recommends using only sealed crimp and solder butt connectors for
all electrical connections.
· To ensure a durable connection, use only good quality crimping tools. · Apply loom to all wiring:
Use high temperature loom in areas where high temperatures may be expected.
Use spiral loom in areas with high vibration.

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

39

VMAC Knowledge Base: www.kb.vmacair.com

Analog Throttle Control Wire Schematic

Figure 53 — Analog throttle control

VMAC – Vehicle Mounted Air Compressors

40

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Digital Throttle Control Wire Schematic

Figure 54 — Digital throttle control

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

41

VMAC Knowledge Base: www.kb.vmacair.com

Pin 85

Pin 38

X2 Engine Control Module (ECM)

Transmission Control Module (TCM)

Figure 55 — ECM / TCM Connectors

(As viewed from “mating” side)

VMAC – Vehicle Mounted Air Compressors

42

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Control Box
Remove the kick panel in the driver side footwell. Mount the Control Box in a convenient location in the cab (such as the
lower dashboard panel), positioned such that the wire harness will reach the compressor. Ensure there is adequate clearance for the door to close before permanently mounting the Control Box.
Throttle Control
Using cable ties, secure the throttle control under the dashboard, away from
moving parts and positioned so that the adjusting screws, or the buttons and LED lights, are accessible.
Connecting the Wiring
Unplug the OEM cable from the accelerator pedal and plug it into the matching
connector from the throttle control. Plug the cable from the throttle control into the matching connector on the accelerator pedal.
Connect the interface harness to the matching connector from the Control Box. Replace the kick panel. Attach the (×2) green wires with ring connectors to a good ground under the
dash. Digital Throttle Control only:
Locate the OBD II port (generally located under the dashboard, beneath the
steering wheel column).
Remove the fasteners securing the OBD II port to the dashboard; this provides
easier access to the wires at the back.
Peel back the tape on the harness a few inches.
The wires populating pins 6 and 14 are a twisted pair (blue and white wires).
*Locate the blue wire connected to pin 6 of the OBD II port (Figure 56).

Figure 56 — OBD II connector
Cut the blue wire approximately 2 in from the back of the OBD II connector. Strip approximately 3/8 in from the end of both wires. *Twist the light blue wire from the throttle control together with the blue wire;
using the supplied butt connector, splice these paired wires to the blue wire at pin 6.

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

43

VMAC Knowledge Base: www.kb.vmacair.com

Locate the white wire connected to pin 14 of the OBD II port (Figure 56). Cut the white wire approximately 2 in from the back of the OBD II connector. Strip approximately 3/8 in from the end of both wires. Twist the grey wire from the throttle control together with the white wire;
using the supplied butt connector, splice these paired wires to the white wire at pin 14.
Lightly tug the wires to ensure they are properly crimped. Using a heat gun, carefully apply heat to the butt connectors to seal the
connection. Route the following wires into the engine compartment via a grommet in the firewall:
Analog throttle control only: White wire from the throttle control
(tachometer signal).
White wire from the 4 pin connector (clutch wire). Grey cable with the green 4 pin connector (temperature sensor). Grey cable with the black 3 pin connector (pressure sensor). Red wire from the white 4 pin interface (key switched 12 V). Long blue wire (automatic transmission only).
Cover all of the engine compartment wires with plastic loom.
Analog throttle control only:
Locate the X2 ECM connector (the X2 connector is the leftmost connector)
located on the driver side radiator support.
Splice the white wire from the VMAC throttle control to the green wire
located at pin 85 (Figure 55 on page 42).
Locate the TCM connector (the TCM connector is located below the ECM
module) located on the driver side radiator support.
Splice the blue wire from the throttle control to the orange wire at Pin 38 on the
X1 connector (Figure 55 on page 42).
Compressor connections
Route the (×2) grey cables and the white wire over to the compressor. Connect the grey cable with the green 4 pin connector to the matching
connector at the compressor.
Connect the grey cable with the black 3 pin connector to the matching
connector at the compressor.
Connect the white wire with the bullet connector to the compressor clutch.

VMAC – Vehicle Mounted Air Compressors

44

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Connecting to Key Switch 12 V Supply
The instructions provided below can be used in cases where no upfitter switched power circuits (minimum 10 A free) are available. The VMAC system can be wired using the directions below or as per GM bulletin UI #148 (Scan or click the QR code).
Locate the junction block located in the driver side foot well, near or below the
parking brake mechanism.
Remove the plastic cover on the junction block by gently prying the (×3) locking
tabs away from the housing to release the cover.
Remove the (×3) nuts securing the junction block (Figure 57).

Top view

Bottom view

Figure 57 — Junction block

Lift the assembly up and out of the way to give clearance to the electrical
connectors on the back of the junction block.
Remove the X1 connector from the junction block (Figure 57).

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

45

VMAC Knowledge Base: www.kb.vmacair.com

Locate the violet wire with white stripe running to pin 30 of the X1 connector
(Figure 58).

Pin 30
Figure 58 — Remove PDC (as viewed from mating side)
Splice the red wire from the VMAC 4 pin interface connector to the violet wire
with white stripe.
Cover the soldered wire with 1/4 in loom, insert the wires back into the OEM loom
and secure with a cable tie.
Reinsert the X1 connector into the junction block. Unplug the connector from the park brake switch and connect the black wire with
the piggyback connector from the interface cable to the connector on the park brake switch.
Connect the OEM park brake connector to the piggyback connector. Reinstall the junction block.
Key switched power is supplied via fuse 30DL in the “instrument panel left” fuse panel.

VMAC – Vehicle Mounted Air Compressors

46

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Air Receiver Tank
If an air receiver tank will be used with this system, a check valve (not supplied) must be installed to prevent damage to the system.
Once a check valve is installed, pressure in the air receiver tank will not be relieved when the compressor system blows down. This is normal operation.
Prior to performing any service work on the system, discharge any stored air in the air receiver tank.
If an air receiver tank will be used with this system, the following installation procedure must be used to prevent damage to the system.
The VMAC compressor system will automatically depressurize when it is shutdown, therefore the hose from the VMAC AOST to the air receiver tank must have a check valve installed; this prevents blow back and moisture from the receiver tank entering the AOST
While the air receiver tank can be installed at any height in relation to the AOST, the discharge hose running from the AOST must be installed as high as possible on the air receiver tank to prevent problems with condensation that may have accumulated in the receiver tank (Figure 59).
Drain the condensed water from the receiver tank daily.
Install the line to the receiver tank as high as possible

Check valve

Air Receiver Tank

AOST

Figure 59 — Air receiver tank

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

47

VMAC Knowledge Base: www.kb.vmacair.com

Recommended Accessories
While the compressor system will function without the following accessories, VMAC strongly recommends their use for optimal performance.
See the “Accessory Product” section of this manual on page 56 for a list of products available for purchase through VMAC.
Receiver Tank
An air receiver tank provides a buffer as it gives the compressor time to react by increasing the engine speed and producing air before the tool stalls. It also has the advantage of lowering the duty cycle of the compressor system.
Pressure Gauge
While not critical to system performance, a pressure gauge is important for fine tuning the system and simplifies any potential troubleshooting. Install a 200 psi pressure gauge downstream of the air discharge valve.
Pressure Regulator and/or Lubricator or FRL
The compressor can produce air pressures up to approximately 175 psi (1206 kPa). It is the responsibility of the user to know the pressure and air flow requirements of the tools powered by the air compressor system.
An appropriate air pressure regulator and lubricator can be installed downstream of the air discharge valve. Failure to regulate the air pressure may cause damage to the tool.

VMAC – Vehicle Mounted Air Compressors

48

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Completing the Installation
Check all wiring, hoses and tubes to ensure that they will not contact any hot
or moving components and will not interfere with the operation of the vehicle. Ensure all wiring, hoses and tubes are secured with cable ties and protected with loom as required.
Pull any excess wiring back into the cab and tie it up and out of the way under
the dash with cable ties.
Replace all dash panels and covers removed during installation. Install the power steering reservoir using the supplied spacers and fasteners
(Figure 60).
(×2) Spacer
Supplied fasteners Figure 60 — Install radiator hose support bracket
Connect the batteries.

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

49

VMAC Knowledge Base: www.kb.vmacair.com

Testing the Installation
Safety Test
Ensure the following has been completed:
Place the automatic transmission in “PARK” and apply the park brake. Turn the
ignition “ON” but do not start the engine.
Check the control box to see if it is illuminated. If there is no display, there is no
power to the control box.
Press the “ON” button. The green LED should come on and the compressor
clutch will engage, this should be audible.
On systems equipped with VMAC’s Digital Throttle Control, the “PRK BRAKE” LED will remain illuminated at all times, regardless of park brake position.
Release the park brake. The green light on the control box should flash and the
display will flash “PARK BRAKE”. Apply the park brake again and press the “ON” button. The green light should come on.
Press the “OFF” button. Turn the ignition “OFF”.
The engine must be running to complete the final steps in the safety test. This will be done after the pre-start checks have been completed.
Place the vehicle in a safe operating position and adequately block the wheels. Ensure that there are no people around the vehicle before beginning the test
Before Starting the Engine Checklist
Ensure the following has been completed:
Verify that the compressor oil level at the AOST sight glass is correct. Verify that the vehicle coolant level is correct. Perform a final inspection of the installation to ensure everything has been
completed.
Check all wiring for security and protection. Ensure nothing is touching the
compressor body.
Install the VMAC Air Test Tool (P/N: A700052) with the 70 cfm (0.190 in) orifice
installed and the ball valve closed.
Ensure all of the compressor outlets are closed. Ensure the parking brake is engaged and the transmission is in “PARK”. Start the engine.
After Starting the Engine Checklist
Check for any leaks, confirm belt alignment, and ensure the belts are rotating
properly.
Close and latch the hood.

VMAC – Vehicle Mounted Air Compressors

50

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Allow the vehicle to reach operating temperature. Turn on the compressor.
Analog Throttle Control
When the VMAC system is first engaged, the engine speed should increase
to between 1,800 rpm and 2,200 rpm and then drop down to VMAC base idle (approximately 1,000 rpm) once system pressure is reached.
Digital Throttle Control
The VMAC digital throttle is a “slow ramp” throttle. Each time the system is powered on, it will quickly increase engine speed to 1,500 rpm; then increase to maximum VMAC rpm over 8 seconds (provided the system has not reached full system pressure before maximum VMAC rpm is reached).
After the initial slow ramp, the throttle will respond normally to air demand
When the VMAC system is first engaged, the engine speed should increase to
1,500 rpm and then drop down to VMAC base idle (approximately 1,000 rpm) once system pressure is reached. With the system running, check for:
Coolant leaks. *Compressor oil leaks. Allow the compressor to run until the system reaches full system pressure. Engine speed should reduce to between 900 rpm to 1,100 rpm. Turn off the compressor. Shut down the engine. Check the compressor oil level after the engine has been shut down and the oil
level has had time to stabilize.
Ensure any stored air is drained from the system prior to adding oil.
Add oil as necessary to bring the level to the “FULL” line in the sight glass and
check for leaks.
Start the engine. Turn on the compressor and allow it to build to full system pressure. Release the park brake.
· The control box should read “PARK BRAKE”, the compressor clutch should
disengage and engine speed should reduce to OEM idle.
Re-engage the park brake and start the compressor. Allow engine speed to stabilize after re-engaging the compressor.

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

51

VMAC Knowledge Base: www.kb.vmacair.com

Analog Throttle Control:
With the brake pedal firmly depressed, shift the truck into “REVERSE”.
The engine speed reduces to OEM base idle (Approximately 650 rpm). The green LED on the control box remains illuminated. Repeat these steps in all gear selector positions to ensure the engine speed
does not increase unless the gear selector is in “PARK” or “NEUTRAL”. Digital Throttle Control:
With the brake pedal firmly depressed, shift the truck into “REVERSE”.
The engine speed reduces to OEM base idle (Approximately 650 rpm). The green LED on the control box remains illuminated. The “STATUS” and “PRNDL” LED’s on the digital throttle control will turn off
and engine speed will reduce to base idle.
Shift the vehicle back into “PARK”. *Cycle the compressor off, then on again to reset the safety parameters. Repeat these steps in all gear selector positions to ensure the engine speed
does not increase unless the gear selector is in “PARK” or “NEUTRAL”.
Allow the compressor to run until the system reaches full system pressure.
Confirm all air valves are closed and the system has no air leaks.
Turn off the compressor.
Ensure any stored air is drained from the system.
Final Testing
Ensure the following has been completed:
Operate the system with an air tool (or the VMAC Air Test Tool with the
appropriate orifice installed) for at least 1/2 hour (1 hour preferred).
Road test the vehicle for approximately 14 miles (20 km). Observe the compressor operation to ensure that the belt alignment is good
and nothing is rubbing or contacting hot components.
Check all components, connections and fasteners once the engine is turned off
and the system has cooled.
Check the coolant level after the engine has been operated. Check the compressor oil level after the engine has been shut down and the oil
level has had time to stabilize.

VMAC – Vehicle Mounted Air Compressors

52

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Performance Testing and System Adjustments

Performance Testing and System Adjustment
System operation can be tested using the tools that will be operated by the system or by using the VMAC Test Tool (A700052) with the 70 cfm (0.190 in) orifice in the outlet to simulate tool use (Figure 61).

JIC Adapters

Orifice

Ball valve

Install orifice here
Figure 61 — A700052 VMAC Air Test Tool
Disconnect all downstream equipment (hose reels, etc.) and connect the test tool directly to the discharge fitting on the AOST.
Ensure there are no leaks in the test tool. The system may not idle down if there are leaks in the lines or fittings.
Install the VMAC test tool at the AOST outlet with the 70 cfm (0.190) orifice. Ensure that the ball valve is closed. Place the transmission in “PARK” and fully apply the park brake. Allow the engine to run until it is at operating temperature. Turn on the air compressor system and allow it to operate until the oil is warm. Observe the pressure gauge. Pressure should be approximately 150 psi.
Open the ball valve on the test tool and observe the engine tachometer:
Analog throttle control: Engine speed should increase to approximately
1,800 rpm ­ 2,200 rpm.
Digital throttle control: Engine speed should increase to approximately
2,400 rpm.
Close the air valve slowly to allow the system pressure to rise. When the
pressure reaches 150 psi (factory setting), the system will close the inlet valve poppet and reduce the engine speed to VMAC base idle (approximately 1,000 rpm).
Once the system pressure is at maximum, slowly open the ball valve on the
test tool until the pressure on the gauge begins to drop. Engine speed should ramp up when the pressure drops to approximately 140 psi. This value can be adjusted via the “IDLE DOWN PRESSURE” (analog throttle) / “RAMP UP PRESSURE” (digital throttle) adjustment.

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

53

VMAC Knowledge Base: www.kb.vmacair.com

Digital Throttle Control Operation and Adjustments
The VMAC digital throttle is a “slow ramp” throttle. Each time the system is powered on, it will quickly increase engine speed to 1,500 rpm; then increase to maximum VMAC rpm over 8 seconds (provided the system has not reached full system pressure before maximum VMAC rpm is reached).
After the initial slow ramp, the throttle will respond normally to air demand.
The throttle control is configured at the factory for optimum performance at maximum cfm. In applications where maximum cfm is not required, or noise is a concern, the throttle control can be adjusted to reduce the maximum VMAC rpm.
Safety features
The throttle control has built in safety features that will disable the system if an unsafe condition is detected, or either of the lock out parameters is not met (the vehicle must be in “PARK” and the park brake must be engaged).
If an unsafe condition is detected, the “STATUS” LED will turn off, and engine speed will return to idle. Once all unsafe conditions have been removed, the system must be cycled off, then on again to reset it. Once the system powers up, the “STATUS” LED will illuminate, and the system will operate normally.

Figure 62 — Throttle control
If the vehicle is placed into gear, the “STATUS” LED and the PRNDL LED will turn off and the throttle control will deactivate. This will reduce engine speed to base idle.
In order to activate the system again, re-engage the appropriate lockout and cycle the VMAC “OFF” then “ON” via the control box.

VMAC – Vehicle Mounted Air Compressors

54

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

The “PRK BRAKE” LED will remain illuminated at all times, regardless of park brake position.
MAX RPM
The cfm produced by the system is directly related to engine speed; this system delivers 70 cfm at 2,400 rpm. Maximum VMAC rpm can be adjusted between 1,000 rpm and 2,600 rpm (in 50 rpm increments) via the “” or “” buttons in the “MAX RPM” column.
If the system is at full system pressure while the rpm is being adjusted, the engine speed will increase to the new value for 4 seconds, then return to base idle.
RAMP UP PRESSURE
“RAMP UP PRESSURE” is the amount of pressure the system will drop before the engine speed is increased to generate air; as air continues to be used and the pressure drops, engine speed will increase until maximum VMAC rpm is achieved.
“RAMP UP PRESSURE” is set to 140 psi (10 psi below the factory default maximum system pressure of 150 psi). This allows for a small amount of air use without the need to increase engine speed.
“RAMP UP PRESSURE” should only be adjusted if the maximum system pressure is changed (via the inlet regulator). To maintain proper performance, and rapid response to air demand, ensure the “RAMP UP PRESSURE” is set at no more than 20 psi below the maximum system pressure.
The “RAMP UP PRESSURE” can be set to “100 PSI”, “120 PSI”, “140 PSI”, or “160 PSI via the “” or “” buttons in the “RAMP UP PRESSURE” column; an LED will illuminate beside the setting that has been selected.
Factory Reset
The throttle control can be reset to factory default values via a button inside the throttle control box.
To perform a factory reset, turn the system on and allow the engine speed to drop to VMAC base idle (approximately 1,000 rpm). Using a paper clip (or similar object), push and hold the factory reset button for 5 seconds. All of the LED lights will illuminate for several seconds while the settings revert to their defaults. Once the LED’s return to their normal state, the system is ready for use again.

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

55

VMAC Knowledge Base: www.kb.vmacair.com

Accessory Products from VMAC
Compressor Service Kits
200 Hour or 6 Month Service Kit Part number: A700019 Includes 5 L VMAC high performance compressor oil, oil filter, air filter, and next service due decal.
400 Hour or 1-Year Service Kit Part number: A700020 Includes 5 L VMAC high performance compressor oil, oil filter, air filter, coalescing filter, pressure relief valve, muffler, and next service due decal.
Air Aftercooler — 70 cfm
Part number: A800070 Improves tool performance and extends the life of air tools; removes up to 80% of water from compressed air; includes automatic water drain.
· Max air flow: 70 cfm / 175 psi. · Port size: 3/4 in NPT inlet and outlet. · Electrical: 12 V. · Dimensions: 17 in (43.2 cm) L × 8.0 in (20.3 cm)
W. × 14.5 in (36.8 cm) H.
· Weight: 35 lb (15.8 kg).
Filter Regulator Lubricator (FRL) — 70 cfm
Part number: A700151 Extends the life of air tools; filter removes contaminants from the compressed air, adjustable regulator can reduce air pressure going to tools, lubricator adds atomized tool oil to the air stream to lubricate air tools (Tool oil not included).
· Max air flow: up to 70 cfm / 150 psi · Port size: 3/4 in NPT inlet and outlet
1/2 in × 50 ft Hose Reel
Part number: A700007 Spring-loaded 1/2 in × 50 ft hose reel; steel construction; full flow shaft and swivel for maximum performance.

VMAC – Vehicle Mounted Air Compressors

56

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

VMAC De-icer Kit
Part number: A700031 Cold climate heater package for operating VMAC compressors in cold climates; proven at temperatures of -30 °C (-22 °F). Requires 12V DC at 10A.
10 Gallon Air Receiver Tank w/ Mounting Feet
Part number: A300047 Air receiver tanks are used for lowering compressor duty cycle and removing water from compressed air. Recommended for optimum operation of VMAC Hydraulic Air Compressors, VMAC Diesel Driven Air Compressors, UNDERHOOD40, UNDERHOOD70 ­ Green Series Air Compressors, and VMAC Multifunction Power Systems, which include standby mode; ASME certified; includes fittings, 200 psi pressure relief valve, tank drain, and 200 psi pressure gauge.
· Max pressure: up to 200 psi. · Dimensions: 30 in (76.2 cm) L × 10 in (25.4 cm) D. · Weight: 33 lb (15 kg).
35 Gallon Air Receiver Wing Tank
Part number: A300010 Air receiver tanks are used for lowering compressor duty cycle and removing water from compressed air. Recommended for optimum operation of VMAC Diesel Air Compressors, Hydraulic Air Compressors, UNDERHOOD40, UNDERHOOD70 ­ Green Series Air Compressors, and VMAC Multifunction Power Systems, which include standby mode; ASME certified; includes fittings, 200 psi pressure relief value, tank drain, and 200 psi pressure gauge.
· Max pressure: up to 200 psi. · Dimensions: 73 3/4 in (187.3 cm) L × 14 in (35.6 cm) D. · Weight: 95 lb (43.1 kg).

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

57

VMAC Knowledge Base: www.kb.vmacair.com

Notes

VMAC – Vehicle Mounted Air Compressors

58

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Notes

VMAC – Vehicle Mounted Air Compressors

VMAC Technical Support: 888-241-2289

59

VMAC Knowledge Base: www.kb.vmacair.com

Warranty Registration

This form must be fully completed and returned to VMAC at the time of installation. Warranty may be void if this form is not received by VMAC within 30 days of installation.
VMAC’s Warranty policy and registration can be viewed online at: www.vmacair.com/warranty

VMAC Dealer Information

Company Name:

City:

State / Province:

Installer Information
Company Name: City: Installation Date: / /
Day Month Year
Owner Information
Company Name: Address: City: Zip / Postal: Email Address:

State / Province:
State / Province: Phone: ( ) ­

Vehicle Information
Year: Vehicle Identification Number: Unit:

Make:

Product Information
System Identification Number: V Compressor Serial Number: P Throttle Control Serial Number: AOST Serial Number:

Submitted by
Name:

Contact:

VMAC – Vehicle Mounted Air Compressors

60

VMAC Technical Support: 888-241-2289

VMAC Knowledge Base: www.kb.vmacair.com

Manufactured by

®

888-241-2289

tech@vmacair.com

877-740-3202

warranty@vmacair.com

www.vmacair.com

www.kb.vmacair.com

1333 Kipp Road, Nanaimo, B.C., V9X 1R3 Canada

Read User Manual Online (PDF format)

Read User Manual Online (PDF format)  >>

Download This Manual (PDF format)

Download this manual  >>