Removing and installing fuel overflow valve: VW 2.5 TDI (BJJ, BJK, BJL, BJM, …)

Removing and installing fuel overflow valve
Special tools and workshop equipment required
Torque wrench
V.A.G 1331
Removing
Caution
When doing any repair work, especially in the engine compartment, pay attention to the following due to the cramped conditions:
Route all the various lines (e.g. for fuel, hydraulics, activated charcoal filter system, coolant and refrigerant, brake fluid and vacuum) and electrical wiring in their original positions.
To avoid damage to lines, ensure sufficient clearance from all moving or hot components.
The fuel and the fuel lines in the fuel system can become very hot (danger of scalding)!
The fuel system is also under pressure! Before opening the system, wrap cleaning cloths around the connection and carefully loosen connection to release the pressure!
Make sure that no escaping fuel runs onto radiator hoses and belts, as these are not resistant to fuel!
Wear eye and hand protection when performing all assembly work on the fuel system!
Remove air filter (see the separate procedure).
Caution
Extreme care and cleanliness are required when removing and installing the fuel overflow valve.
Use only lint-free cleaning cloths.
A fuel overflow valve which has been removed must always be renewed.
Additionally renew fuel accumulator (new part number with index
“A”)
Electronic Parts Catalogue on right in engine compartment.
Carefully clean area around high-pressure pump (1) with cleaning agents.
Then blow all surfaces dry with compressed air.
Place lint-free cloths below high-pressure pump to collect escaping fuel.
Completely remove guide tube (1) for oil dipstick
Item.
Remove fuel supply pipe (2) and fuel return pipe (3) from high-pressure pump (4).
Catch escaping fuel with a cleaning cloth.
Note
Seal pipe openings (1) and (2) with a lint-free cleaning cloth.
Using an appropriate
16 mm ring spanner e.g., release fuel overflow valve (3) approx. 2 revolutions.
Then again clean area around fuel overflow valve.
Then unscrew fuel overflow valve.
Clean particles of dirt from threads in high-pressure pump.
Installing
Installation is carried out in the reverse order; note the following:
Renew fuel overflow valve.
Coat fuel overflow valve threads and seal with fuel.
Screw fuel overflow valve back in, and tighten it.
Note
Renew oil seals.
The high-pressure pump must first be filled with fuel before the engine is started (see the separate procedure).
Avoid allowing the high-pressure pump to run dry under all circumstances.
Fit fuel supply line (2) and fuel return line (3) with new seals and install on high-pressure pump (4).
Install guide tube (1) for oil dipstick
Item.
Additionally renew fuel accumulator (1) on intake manifold
Item.
Pull off both pipes (2) at fuel accumulator to do this.
Note
Note new part number with index
“A”
Electronic Parts Catalogue for fuel accumulator.
Caution
Risk of irreparable damage to high-pressure pump if allowed to run dry.
The high-pressure pump must first be filled with fuel before the engine is started (see the separate procedure)
. Avoid allowing the high-pressure pump to run dry under all circumstances.
Check fuel system for leaks (see the separate procedure).
Specified torques (see “Assembly overview - fuel system”)