Mercedes diesel handpump has vacuum lock and won't pump fuel

Submitted by mikiebenzo on 31 December 2006 - 10:18am.

85 300td odd, what can cause this kind of fuel starvation? handpump snaps closed when pulled and let go...leaked before this. filters are showing tank of sediment and maybe algae. even after removing fuel lines, vacuum created in handpump remains.

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Possible check valve failure

31 December 2006 - 1:38pm

Kent Bergsma

This sounds like the checkvalve in the hand pump or in the injection lift pump (on side of injection pump) has failed. Since the hand pump was already leaking previously I would recommend replacing that first. We offer two different style hand pumps. CLICK HERE to view both types.

If you are still having problems after replacing the hand pump you will need to look into the lift pump.

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Eric and Carla V - With warmest regards

Hi Kaia,

Here are some pictures. We have done a ride of 400 miles yesterday with heavy rain, snow, wind and traffic jams. No troubles or what so ever and 29 miles to the (American 3.8 ltr.) gallon. Look forward of your expert opinion. Did some work on the SD lately. New windshield and seal, new rear window seal (California car)

New injectors (Bosch) wow she's quiet now, new motor mounts, swaybar kit, ... Read More

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Mercedes diesel handpump has vacuum lock and won't pump fuel

Possible check valve failure

Eric and Carla V - With warmest regards