Fuel Supply System Components,Discription and Operation

NOTE:
Hose connections are secured with either screw spring or clamp-type clips.
Always replace clamp-type clips with screw or spring-type clips.
Fuel hoses In engine compartment must only be secured with spring-type clips. The use of clamp or screw-type clips is not permissible.
VAG 1921 pliers are recommended for installing spring-type clips.

NOTE:
Observe safety precautions.
Observe rules of cleanliness.

Fuel System Components,Description & Id.:

NOTE: After all repairs to the fuel supply unit or the fuel gauge sender unit have been carried out, ensure that supply/return hoses do not make contact with the fuel tank which could cause pump noise transferance

1 Collar nut
- Remove and install using tool 3217.
2 Fuel return line
- Blue
- Secure with spring-type clips.
3 4-pin harness connector
- Black
- For Fuel Level sensor and Fuel Pump.
4 Flange
- Note installed position on fuel tank.
- Underside marked with a "V" (for supply) and an "R" (for return) hoses.
5 Supply hose
6 Return hose
7 Sealing ring
- Coat with fuel when installing.
- Replace if damaged.
8 Fuel Level sensor.
9 Fuel delivery unit
10 Strainer:
- Clean if contaminated.
11 Fuel tank
- When removing; support using engine/transmission jack VAG 1383A.
12 Mounting straps:
- Note different lengths.
13 Torque specs:Nm (18 ft lb)
14 Bracket:
- For mounting straps.
15 Splash shield
16 Retaining ring
17 Gasket
- If damaged;
- Replace together with cap as an assembly.
18 Cap
- 10 Nm (7 ft lb)
20 Check valve:
- For fuel tank breathing
- For checking: See Fig. 3
21 Breather tube:
- To junction piece between EVAP canister and EVAP canister purge regulator valve See Below.
22 Breather tube
23 Supply line
- Black
- Mount using spring clips. Ensure it is securely seated to fuel supply line (on lower intake manifold).
24 Fuel filter
- Installed position:
- Arrow points in direction of flow.
25 Bracket:
- For fuel filter.
26 Breather tube:
- Fill vent
27 O-ring
28 Gravity/vent valve,cannot be removed.
- Replace as an assembly together with filler neck.
- Checking:See Fig. 2 .




Fig. 1 Fuel delivery unit/Flange, installed position.
- Marking on flange must align with marking on fuel tank.




Fig. 2 Gravity/vent valve:
- Checking:
- Lever in rest position:
- No Flow.
- Lever pushed in direction of arrow:
- Flow




Fig. 3 Check valve, checking From the direction of the gravity/vent valve,check valve is open in both directions of flow arrow -1->.
- From the direction of the EVAP canister/EVAP canister purge.
- Regulator valve 1 junction piece:
- Check valve is open in only one flow direction: arrow -2->.