Audi S8 High Pressure Fuel Pump Installation Guide

Table of Contents

Removing and installing high-pressure pump

Removing

WARNING
Danger of fire and damage if the engine cover panel is not fitted.

The engine cover panel must always be fitted before the bonnet is closed.
If the engine cover panel is not fitted, it is not permissible to start or drive the vehicle with the bonnet closed.

Note
Do not hold onto or pull on plunger of highpressure pumps.
Cylinder bank 1 (right-side), vehicles with engine codes CEUA/CTGA:

Cylinder bank 1 (right-side), vehicles with engine codes CGTA/CTFA:

Cylinder bank 1 (right-side), all engines:

Remove bolts -arrows- and push wiring guide -1- slightly to right side.
Unplug electrical connector -1-.
Release hose clips -2 and 4- and detach fuel hoses. **WARNING**
The fuel system is pressurised.
Risk of injury as fuel may spray out.
- Wear safety goggles.
- Wear protective gloves.
- Release pressure (wrap clean cloth around connection and open connection carefully).
Wrap clean cloth around connection, remove union nuts -3- and press highpressure pipe to one side.
Remove bolts -arrows-.

Cylinder bank 2 (left-side):

Unplug electrical connectors -3-.
Release hose clip -4- and detach fuel hose.
WARNING
The fuel system is pressurised.
Risk of injury as fuel may spray out.
- Wear safety goggles.
- Wear protective gloves.
- Release pressure (wrap clean cloth around connection and open connection carefully).
Wrap clean cloth around connection, remove union nuts -2- and press highpressure pipe to one side.
Remove bolts -1- and -arrows-.

Both sides (continued):

Carefully pull out high-pressure pump. It is possible that the roller tappet may remain lodged inside.

Note
Do not attempt to bend high-pressure pipe to a different shape.

Note

Do not hold onto or pull on plunger of highpressure pump.
Fit new O-ring.
Secure all hose connections with the correct type of hose clips (same as original equipment) → Electronic parts catalogue.
The connections of the high-pressure pipe must not be damaged.
Do not attempt to bend high-pressure pipe to a different shape.
Check roller tappet -1- for damage and renew if necessary.
Lightly lubricate roller tappet with oil and insert it so that lug -arrow A- slides into guide notch -arrow B-.
Disconnect vacuum hose -1-.
Unscrew bolts -3- and remove vacuum reservoir -2-.
Fit turning-over tool -T40272- onto wrench (21 mm) -T40263-.
Position adapter on bolts of vibration damper.
Semi-circular recess -arrow A- on turning over tool -T40272- must point to semicircular recess -arrow B- on vibration damper. **Note
** Disregard notch on turning-over tool -T40272 -.
Rotate crankshaft in direction of normal engine rotation -arrow- using wrench (21 mm) -T40263- and turning over tool T40272-, and at the same time press roller tappet into cylinder head until it reaches lowest point.

Remaining installation steps are carried out in reverse sequence; note the following:

WARNING
Danger of fire and damage if the engine cover panel is not fitted.

The engine cover panel must always be fitted before the bonnet is closed.
If the engine cover panel is not fitted, it is not permissible to start or drive the vehicle with the bonnet closed.