Fuel Pump Seal Rebuild

Aqua Puttana

Poly - Thread Finder
OM612 high Pressure Fuel Pump seal replace install repair

Not a complete Write-up as such, but some good information.

Thanks goes to Toobiloo. :thumbup:

This is a pretty old thread but was useful so I figured I’d post my experience.
I have a OM 612, it started to leak fuel at low temperatures, so I determined it was the high pressure fuel pump. The leak was pretty constant, so needed to be fixed.
I contacted Dr. A but he no longer rebuilds the pumps, so that left me trying to find a decent price for a rebuilt pump or attempting to replace the seals myself.
I decided to attempt the seal replacement myself.
I bought this seal kit:

The kit includes the big o-ring that fits between the pump body and the crankcase. The seal did not exactly match the seals that came out of the pump, but they seamed to be the same sizes.
I followed procedure outlined by surly old bill to get the pump out, and this Utube vid to replace the seals:

Somewhere I picked up a useful tip, which was after the pump was re- installed, I left the high pressure fuel line off (the steel fuel line) and fit a piece of tubing over the pump side of the connector and turned the motor over to run some fuel through the system to flush out any possible contaminants. After I flushed through a fair amount of fuel, I hooked the high pressure fuel line.
So far the repair is working, but it is still early days.
Feel free to expand upon the information.

:cheers: vic


Do you really need to take the whole front end off? I did it for a water pump but this seems a bit much..

Aqua Puttana

Poly - Thread Finder
The OM612 engine/fuel pump would be found in NAS aka NAFTA 2001 - 2003 Sprinters.

The OM647 engine/fuel pump is found in the NAS aka NAFTA 2004 - 2006 Sprinters.

The pumps are different.

:cheers: vic

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