BENNETT Standard (Classic) Hydraulic Trim Tab Systems Owner’s Manual

BENNETT Standard (Classic) Hydraulic Trim Tab Systems Owner’s Manual

System Specifications

SYSTEM COMPONENT SPECIFICATIONS

System Information

Bennett Trim Tabs are built to rigid quality standards. However, the marine environment is harsh. So, in the unlikely event a malfunction occurs, here is some helpful information:

1. If trim tabs do nothing . no movement . . no sound from HPU:

• Inspect for blown 20 amp in-line fuse in helm control’s orange wire.
• Inspect for disconnected or corroded connections on HPU ground wire, orange positive wire from helm control, and quick-disconnect plug.

2. If HPU runs but trim tabs do not move:

• Inspect for disconnected or corroded red and green wire connections at helm control and quick-disconnect plug.
• The following test can be used to help isolate malfunction. Remove wires from helm control and touch together as follows:

If trim tabs function in each of the above combinations, check helm control. If during this test trim tabs continue to malfunction, inspect HPU.

3. If one trim tab operates and the other one does not:

• Inspect for disconnected or corroded red or green valve wire connections at helm control and quick-disconnect plug. (Red wire operates port trim tab; green wire operates starboard trim tab).
• Reverse hydraulic lines at front of HPU to determine if malfunction is in HPU or actuator / hydraulic connections. If after reversing lines, symptom shifts to other trim tab, malfunction may exist in HPU. If symptom remains on the same side, malfunction may exist with the actuator/hydraulic connections.

4. If trim tabs go down but will not retract:

• Inspect for low voltage of the battery. Check battery for voltage while HPU (or another accessory) is running. If voltage is less than 10 volts, valves may not open.
• Inspect for disconnected or corroded connections on helm control, and quick-disconnect plug.

This general information is not intended to be complete. Please feel free to call Bennett Marine to assist in solving situations not clarified or addressed above. Bennett Marine customer service is available to help Monday through Friday, 8am to 5pm Eastern time. 954-427-1400.

MAINTENANCE

• Periodically, check fluid level in HPU. With trim tabs completely retracted, fluid level should be about 2″ from bottom of reservoir (approximately 22 ounces).
  To refill, remove lexan cover and filler plug located at the front left hand corner of the reservoir. FILL WITH ANY TYPE AUTOMATIC TRANSMISSION FLUID (ATF) ONLY. Brands or types of ATF can be mixed. Running HPU with an excess or lack of fluid will not cause damage.

• Periodically, check for clean electrical connections on back of control, HPU ground wire, and quick-disconnect plug.

• Cold temperatures do not affect the trim tab system. No winterization is necessary.

• (SALTWATER ONLY) To deter electrolysis, a zinc anode should be attached to the top of each trim tab. Zinc must make direct contact with stainless steel. Do not paint zinc. Do not ground trim tabs to other underwater appendages.

• Paint trim tabs to discourage marine growth.
  I. Clean surface of all grease, oil, dirt.
  2. Apply two coats of epoxy metal primer.
  3. Apply two coats of anti-fouling paint.
  Actuator, including the piston, may be painted.

• Unpainted trim tabs may acquire an orange discoloration. THIS OXIDATION OF SURFACE CARBON MOLECULES IS NORMAL. The integrity of the stainless steel is not affected. Orange coating can be cleaned off, but may eventually return. Note: This discoloration should not be confused with the pitting and corrosion of electrolysis.

SAFETY INFORMATION

• Take immediate action to correct any malfunction or failure of your trim tabs.
• Occasionally, check for loose or corroded wiring connections.
• Stepping on the trim tab may cause damage to the unit, or injury.
• Make sure the HPU is mounted in a dry location to avoid drenching and consequent failure.
• Leaving the actuator extended when boat is not in use will not cause seal damage.
• Occasionally, inspect HPU fluid level.
• REFER TO SAFETY PRECAUTIONS ON PAGE 4.

How to Use Your Trim Tabs

RUNNING IN ROUGH WATER
When running in a chop or heavier seas, press “Bow Down”. This will bring the “V” of the hull in contact with the waves rather than having the waves pound the hull and your passengers. In a following sea or when running an inlet, the trim tabs should be fully retracted for maximum rudder response.

CORRECTING FOR A LIST
Bennett Trim Tabs are operated individually so that you can correct for listing. Your control is designed so that you can use it “intuitively”. Do not think about what the trim tabs are doing, just concentrate on the bow. If the port bow is high, push the port-side “Bow Down” direction.

If the starboard bow is high, push the starboard side “Bow Down” direction until the boat is level.

TRIM TABS WITH POWER TRIM – GETTING OPTIMUM SPEED AND POWER
Using your trim tabs in conjunction with your power trim will give you increased speed and power.

1. Adjust the trim tabs to achieve a planning attitude.
2. Use the power trim to position the prop path parallel to the water flow.
3. If necessary, just the trim tabs to “fine tune” your tabs. In other words, use your trim tabs to trim the boat and your power trim to trim your prop.

CORRECTING FOR PORPOISING
Porpoising is a condition more common in faster, performance boats. As speed increases, the bow repeatedly rises out of the water until gravity overcomes lift and the bow bounces down. Press “Bow Down” in half second bursts. As the trim tabs deflect, the proposing subsides and your speed should remain the same or increase. Only a slight amount of trim tab deflection should be necessary.

SAFETY PRECAUTIONS

• Do not overtrim, particularly at high speeds as the bow will dig in and wave action may cause the boat to veer.
• While underway, do not move one trim tab significantly farther down than the other as undesirable listing could occur.
• Use your trim tab helm control with caution.
• For best maneuverability, trim tabs should be fully retracted in a following sea, or when running an inlet.
• Improper use of trim tabs can cause an accident or injury.

Bennett Trim Tabs have a significant effect on the operation and versatility of your boat. No one knows your boat better than you, the best learning method is to spend time getting familiar with your boat’s reaction to the trim tabs. As your experience with Bennett Trim Tabs increases, so will your enjoyment. Always operate your boat with safety first in mind.

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