Fuel Leak at Rear of Car

Fuel Leak at Rear of Car

Last week I smelled gasoline in the garage so I checked the lawnmower, weed whacker and even my wife's van. Finally, I moved to my trusty 928 and found the culprit. Small drops of fuel form on the bottom of the external fuel pump and drip, about one every 15 minutes. With the car running, there is no leakage. It seams to stop leaking about 4 hours after the car is shut down. Do you think this is from the fuel pump, or is it likely to be running down from somewhere else? I checked the fittings on the fuel lines, and they seem tight. Does anyone know the torque value for these fittings? Any and all help is appreciated.

87 S4 5sp

It is very common for the check valve to not get tightened good enough, the
check valve screws into the output side of the fuel pump and due to the
electrical connections on each side it is hard to tighten properly.

Here is the solution.

A- Disconnect ground strap from battery.

B- Remove service cover to gain access to the pump/filter area.

C- Use locking pliers (needle nose preferred) to pinch rubber hose from tank to input side of fuel pump cutting off flow from tank.

D- Remove Cap nut from output side of Fuel Pump

E- Loosen or remove Fuel Pump retaining strap

F- Slide Fuel Pump towards left side of car so to get it out of the metal Pump to Filter Fitting.

G- Angle Fuel Pump enough to gain access to check valve with deep set 17mm socket and tighten check valve. I do not know the torque spec, but since you will be counter-holding the pump with your hand, tighten it as tight as you can.

H- Reverse assembly, wash down area well with water , let dry and start engine to check for leaks.

Let me know if you need more info. I also have a pump/filter/check valve install/removal procedure with photos on my website in the "928SP Tips" Section.

David Roberts

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