OM602 Injection Pump - Questions - PeachParts Mercedes-Benz Forum

JamesDean · #1 07-22-2014, 08:31 AM

Morning All,

I've got a number of leaks on my 602's injection pump. Some are oil, some are fuel. They are causing it to idle extremely rough.

A video showing two leaks, dripping nicely as it idles horrible:
MVI_0302_zps93a26a14.mp4 Video by JamesDean59 | Photobucket

I was looking in the EPC at seals and noticed that the drawing in the EPC does not account for a part on my IP, at least I did not see it.

What is the indicated item? What does it do? I see fuel dripping out of a corner of it (above video)...

DieselPaul · #2 07-22-2014, 08:34 AM

That's the Vacuum Control Valve for your automatic transmission. There should not be anything that can leak out of it.

Based on the amount of crud sticking to them and your rough idle, I'd say your delivery valves are shot.

JamesDean · #3 07-22-2014, 08:48 AM

Quote:

Originally Posted by DieselPaul

That's the Vacuum Control Valve for your automatic transmission. There should not be anything that can leak out of it.

Based on the amount of crud sticking to them and your rough idle, I'd say your delivery valves are shot.

Ah that explains why it was not in the EPC drawing. It might be the case that the leak just drips around it and looks like its coming from it.

You can see it in the video.

Shot as in the entire valve assembly should be replaced or the seals should be replaced? Aside from the ****ty idle it drives perfectly normal once you get above idle rpms. At last check I was still getting respectable fuel economy at 75mph (31-32mpg).

DieselPaul · #4 07-22-2014, 01:30 PM

There is a rubber O-ring on the DV valve holder, and when you take it off there is a copper crush washer on top of the delivery valve.

The DV holders themselves only go bad if you over-torque them and break them off in the pump... had to help a friend out of that the other day, Inch-Pounds and Foot-Pounds are very different

The O-rings should be

P/N - 0179974148 (Reinz number)

Crush Washers

P/N - 0049974540 (Bosch Number)

This is a 606 but the tool and method are the same

http://www.peachparts.com/Wikka/OM606DeliveryValveSeals

They are letting air in at low rpms, but when you come off idle and fuel pressure jumps up it becomes much less noticable.

JamesDean · #5 07-22-2014, 01:41 PM

Thanks. That at least takes care of one of the problems.

What about the visible fuel leaks in the video?

Should I have the pump removed or just do the DV seals with the pump in place?

DieselPaul · #6 07-22-2014, 01:46 PM

I always tdo DVs in place. Im at my office, I can't see your videos.

JamesDean · #7 07-22-2014, 01:52 PM

Quote:

Originally Posted by DieselPaul

I always tdo DVs in place. Im at my office, I can't see your videos.

Ah. No problem. There is a visible drip/leak that appears to be coming from the back of the IP. It might be just dripping from there and coming from somewhere else, not sure. I might have to fire it up and get a mirror to find it.

I was planning on putting an order in to MB, maybe I'll pick up the DV seals parts as well and that special socket.

JamesDean · #8 07-23-2014, 11:40 PM

Alright. Seals ordered, socket ordered. I'm going to borrow a dial type torque wrench from work. Expensive looking snap-on tool.

I read in a few places that there is a specific tightening procedure that should be followed when doing this? Any comments on that end?

Edit found it:

install new copper ring and O ring
torque to 30 Nm > loosen
torque to 30 Nm > loosen
torque to 35 Nm

IMPORTANT: clean the pump exterior and wash your hands before embarking on this repair. Watch out for dirt getting into the pump.

There is a spring under the delivery valve holder, don't lose it.

Procedure:
http://www.benzworld.org/forums/w123-e-ce-d-cd-td/1547587-leak-top-injection-pump-my-gray.html

JamesDean · #9 07-26-2014, 06:30 PM

Done!

The o-rings were not horrible. They were certainly squished and a little deformed but none were super brittle.

The holders were very tight though. At least it seemed so to me. I had to stand at the front of the car and jerk them a few times they came free and that was using a 1/2D socket wrench.

Hopefully this will fix something, I know there are still other leaks. Not sure if they can be fixed with the pump installed or not.

I'm letting the collars sit in the sonic cleaner for a while. After that I'll put them on, the hard lines and crank like hell.

JamesDean · #10 07-26-2014, 07:46 PM

Bah.

I should have looked better at the leak.

#4 injector hard line has a break in it. Its pissing diesel on the top of the pump which is flowing everywhere. I had to remove the cruise control actuator and use a mirror to actually see it.

601 070 40 33 is the latest part number for the line.

JamesDean · #11 08-01-2014, 08:42 PM

Bah x2.

#5 injector line is also broken.

#4 was literally machined to death. It must have been rubbing on a metal clip for a long time. I'll post a picture at some point here.

I'm going to order a new #5 line, and all new retaining clips to prevent this from happening again.