5.9 Cummins Bosch injection pump leak

newoodguy78 · April 05, 2021, 10:52:14 PM

I recently fired up a 5.9 that had been sitting for quite awhile.
When I was priming the fuel system by hand I noticed the top of the pump started to weep at the base of the the throttle return spring.
Once I ran it it was a very steady drip.
Just wondering if anyone has experienced this I'm guessing it's an oring or seal that has dried out and also if this is a difficult fix.
I've never messed with internals on an injection pump and hate to open pandoras box, but am not afraid of jumping in either.

The second picture shows the source of the leak the best , it's coming from the base of the spring that is behind the jam nut on the linkage rod.
Thank you for any input

Southside · April 05, 2021, 10:55:42 PM

@mike_belben

mike_belben · April 05, 2021, 11:00:09 PM

Im sorry but i dont have any experience with bosch VE pumps and dont want to steer you wrong. Im sure a large body of info on it is just a google away. Competitiondiesel.com aka 'compD' is a wealth of top info on all things passenger diesel.

It is purely a guess that the throttle shaft will have a seal where it passes through the housing, and has failed, allowing low pressure galley fuel to weep out.

newoodguy78 · April 05, 2021, 11:10:54 PM

That's kinda what I'm thinking myself. Would love to hear it's an easy fix if not we've got a pump shop that been great to deal with that will be getting a call ;D

Oliver05262 · April 06, 2021, 07:21:12 AM

I have only done two; one just leaked like yours. The other broke that shaft because the TJ throttle linkage was worn and allowed that shaft to be the throttle stop. D&W advised that resealing that pump is a pump shop job (surprise), and the customer accepted that. Not cheap, either.
Not a hard job to R&R the pump, and I learned how on YouTube. I will caution that it is easy to lose the shaft key when you reinstall the pump. Peen the edges of the key way slightly to hold the woodruff key securely when you put it back on. A puller "could be" homemade to pop the gear loose from the shaft, but they are cheap enough on Amazon. The lower inside retaining nut is difficult to get to, and the Amazon bent wrench will need to be ground down to get on it. Put a magnetic dish underneath the pump if you are afraid you'll drop it. On a TJ 240 with a 3.9 that I did one on, the hydraulic pump had to be pulled back to get that nut off.
Repeat the warning about that woodruff key. If you lose it in the timing cover.....find it or risk gear damage. The one I dropped just happened to land on a web of the inner timing gear cover and I snagged it with a magnet.

newoodguy78 · April 06, 2021, 07:38:18 AM

Thanks Oliver I'll check out YouTube some more started to last night and fell asleep.
Funny one you did was on a Timberjack , that's where this motor started it's life

azmtnman · April 06, 2021, 09:55:04 AM

That's what is in my '88 Chevy R-30. It is an '86 BT-6.
Mine has leaked after it sits for a while. For years, it would quit leaking after we drove it a bit. Now it leaks a little more and doesn't seem to go away. BUT......the leak has been small enough for like 12-15 years we haven't messed with it.
I've used Lucas fuel treatment and don't know if that slowed it down or just driving it.

barbender · April 06, 2021, 01:40:17 PM

I had a Bosch VE pump on my first Dodge Cummins, and it developed the same leak. I took it to a mechanic who said he could fix it. Get it (and the bill) here he just sent it to a pump shop and they rebuilt the whole thing. About $2000🙄 I don't let them out of my sight now, I'm sure it was just the o-rings.

sawguy21 · April 06, 2021, 02:36:26 PM

Yeah, the $$ appear in their eyes when diesel is mentioned. :

My 05 5.9 developed an annoying leak that I thought was the high pressure line to the rail. Turned out to be the #1 injector line at the rail, fuel was running down and dripping off the lowest point which of course is the pump. Loosened the fitting, gave it a shot of brake clean and retightened. I found a GOOD diesel tech, he is not long out of school but knows his stuff.

newoodguy78 · April 06, 2021, 07:54:02 PM

Quote from: barbender on April 06, 2021, 01:40:17 PM
I had a Bosch VE pump on my first Dodge Cummins, and it developed the same leak. I took it to a mechanic who said he could fix it. Get it (and the bill) here he just sent it to a pump shop and they rebuilt the whole thing. About $2000🙄 I don't let them out of my sight now, I'm sure it was just the o-rings.

If the pump shop thinks it'll be 2 grand to fix one of two things will happen. I'll be learning how to reseal it or it'll get a can wired to it to catch the drip ;D. I'd like to run it for awhile and see what other if any issues arise. Currently waiting for some parts I ordered the beginning of last week. Other than that this old girl is ready to roll some dirt 8)

kiko · April 06, 2021, 10:03:15 PM

How To DIY - [url=http://www.diydieselshop.com]HOME - www.diydieselshop.com[/url]

This is easier than trying to explain, there are two different bushings.

newoodguy78 · April 07, 2021, 06:04:41 PM

Thank you for everyone's suggestions especially @kiko and @oliver05262
After talking with the parts guy who is also a Cummins and Agco dealer watching videos and the link kiko posted I'm gonna try it, he said replacing the oring/seal on the throttle shaft wasn't too bad. The key is measuring the distance the fuel adjustment screw sticks beyond the case before taking the cover off as it has to be removed. Ordered the seal kit for 40 bucks.
If anyone is looking for White tractor/Cummins parts I'd be happy to pass their info along. Very knowledgeable and easy to deal with they're located in Ohio
Thanks again

MakitaDolmar · April 10, 2021, 09:31:28 PM

I've messed around with a lot of Cummins and quite a few VE pumps...I say have the entire pump resealed. Any Bosch shop can do it and honestly if its got 1 leak now the rest of the seals are at the same point. The shaft seal behind the gear is an important one; it keeps diesel fuel from pumping into the engine through the timing cover. At the least pry that out and replace.

newoodguy78 · May 02, 2021, 09:02:01 AM

Finally got to put this repower to work. Was more than pleasantly surprised that the leak seems to have fixed itself. I never have luck like this but I'll take it ;D. Ran it for probably 10 hours yesterday disking and plowing. More than enough time to cover any leaks in dust.
The zip tie is part of my prototype linkage to make sure it would work I'll be doing something more permanent there.
I do have the seal kit ordered for the pump just in case, don't get me started on waiting for parts that aren't in stock