123 injection pump leak at delivery valve - PeachParts Mercedes-Benz Forum

jfowler · #1 10-12-2008, 06:36 PM

I have done a search for strings addressing this issue but cannot find pictures or diagrams telling me what everything is and where there should be a replaceable crush washer on the injection pump for a 1985 300TD injection pump.

I removed the #1 delivery valve, spring, and whatever the spring rides on top of to do a drip test for i.p. timing last week. I also pulled out whatever the little valve thing under the spring rides inside of (I thought maybe it was a washer but it is about 3/4 of an inch deep with a hole in it) and put it back before the drip test. I put it all back together and have diesel leaking from the delivery valve threads. I did not see any crush washer between these parts. I took apart once more to check that it was all together ok and that I didn't crack any threads, etc. I had read about a groove that needs to be aligned but saw nothing of the sort on any pieces (except for the four grooves on the thing that the spring rests on that I assume diesel travels along when it is pushed up out of the piece it rests inside of. Sorry for the lack of terminology here. Terms and diagrams, pictures, explanations would be a great help (or direction to a thread that has already been over this). This is about the last issue my wonderful car has now.

-Jeb
Austin, TX

#2 10-13-2008, 02:25 AM

There is a copper crush washer. Its likely stuck either to the underside of the delivery valve holder or to the barrel of the plunger body.

The washer is #5 in the picture.

Do NOT even loosen the hold down nuts of #6 or the base timing of that cylinder will be changed and the injection pump will have to be recalibrated on a test bench.

latitude500 · #3 10-13-2008, 02:26 AM

Mind you I'm in the process of doing research into replacing my delivery valve when I get my nozzles in. But I did read up and find out that you need to replace the rubber gasket and the copper washer. Did you end up replacing these two parts when you did your job?

Just a thought.

#4 10-13-2008, 03:01 AM

There is no rubber gasket on his engine. That only applies to 190D and 86+ 300D/TD/SD/SDL models.

jfowler · #5 10-13-2008, 03:07 PM

ForcedInduction, you rock. That diagram was exactly what I was looking for. I thought I was spotting a washer down there but I was afraid to take anything else out since I thought I had already committed a no-no in taking #4 out. I wouldn't dream of removing #6 ( I have seen other posts where you warned against this). Thank you. Any chance you could list the nomenclature of part #'s 1-6?

-Jeb

Diesel911 · #6 10-13-2008, 03:16 PM

For comparison here is a pic of the newer IP parts; the ones that do have the O-ring. Also note that the Crush Washer is on the top of item #5 the Delivery-Valve Support and under item #1 the Pressure Valve holder/Delivery Valve holder. On the older IPs (not shown) the Crush Washer is at the bottom of item #5 (which also has a different shape) in the part labled "Lapped Surface" in the pic.
This pic is from a Bosch book so the terminology of the parts may not be exactly the same as Mercedes uses.

#7 10-13-2008, 03:37 PM

Quote:

Originally Posted by jfowler

Any chance you could list the nomenclature of part #'s 1-6?

Here.

jfowler · #8 10-13-2008, 06:54 PM

Thanks, folks. For anyone looking for this part, the MB dealer computer system does not detail any Bosch parts when they pull up the 617 engine. We were able to find the washer only after having him look it up on the 603 engine. It is the same copper washer (or seal), though. I've pressure washed the engine after replacement and will update as to whether the leak is gone. I suspect this will have done it. And yes, it definitely goes under the delivery valve carrier on my model pump.