Visit our Popular Forums

eweb101 · 24-03-2019, 18:57

I've developed a pretty substantial leak in my fuel injection pump and am not sure how to fix it. The engine is a mid-2000's Volvo Penta MD2040-D. In the diagram I attached, it looks like it's leaking under the flange of part #9. As if the two o-rings, #10, need to be replaced.

I don't think I can take part #9 out of the pump body as the screws holding it to the pump body aren't standard screws.

Is this kind of leak something that would make me have to have the pump rebuilt? Or is there some way to get to the o-rings and change them.

belizesailor · 24-03-2019, 19:50

These are pretty basic pumps, so it is feasible to DIY some repairs, but what you cant do is proper testing. A diesel lab is set up to do that. I would take it in for evaluation at least. That should isolate the problem and tell if there are other things that need attention too.

eweb101 · 25-03-2019, 04:35

Quote:

Originally Posted by belizesailor

These are pretty basic pumps, so it is feasible to DIY some repairs, but what you cant do is proper testing. A diesel lab is set up to do that. I would take it in for evaluation at least. That should isolate the problem and tell if there are other things that need attention too.

I was hoping someone would know an easy fix since the pump works well, except for the leak.

If I can't figure something out, I'll pull the pump later today and try to find someone to repair it.

DougR · 25-03-2019, 10:13

It could be O rings #10, or it could also be O ring #8 under the delivery valve retainer, which would look very similar to #10, only with the fuel coming up around the threads of the retainer.

Probably the best thing is to pull the pump and have a diesel fuel shop have a look at it. It should be an easy fix.

If you pull the pump, take extra care of the gaskets and shims between the pump flange and the block. The combined thickness of the combination of gaskets and shims here, or several gaskets, determines the injection timing of the pump. You want to go back with the same thickness as that which was there to begin with.

DougR

eweb101 · 25-03-2019, 14:03

Two do-it-yourselfers telling me to take the pump into a shop.

I took your advice, pulled the pump, and took it into superior diesel to get it looked at.

thanks for the replies.

belizesailor · 25-03-2019, 16:04

Be very careful with alignment when putting the pump back in. I got one slightly misaligned once and put a hairline crack in the pump body...not good.

Also, this is a critical torque item so you should use a torque wrench to get right.

Check oil level frequently after reinstall to confirm you dont have any internal leaks...which could result in run away.

eweb101 · 26-03-2019, 07:33

How do you fix a crack in the pump body? Do you have to buy a new pump or did you JB weld it?

belizesailor · 27-03-2019, 07:10

Apparently something was slightly misaligned and it developed a hairline crack when I brought it up to torque spec. I discovered it, fortunately, by a rise in oil level (diesel was leaking into sump). I replaced the pump body.

eweb101 · 28-03-2019, 05:53

Wow. That was an expensive little crack.

You must've posted about it in another thread. I remember reading it the last time I had to pull an injection pump and buying a torque wrench because of it.

Sailor 99 · 28-03-2019, 06:08

Quote:

Originally Posted by eweb101

Two do-it-yourselfers telling me to take the pump into a shop.

I took your advice, pulled the pump, and took it into superior diesel to get it looked at.

thanks for the replies.

Even the tough guys get a doctor if they need heart surgery.

belizesailor · 28-03-2019, 08:45

Quote:

Originally Posted by eweb101

Wow. That was an expensive little crack.

You must've posted about it in another thread. I remember reading it the last time I had to pull an injection pump and buying a torque wrench because of it.

Yes it was, but sure was a lot cheaper than a run away!

When reinstalling the pump you are working against the spring loaded plungers, so aligning it properly can be harder than it seems. Probably a trick or special tool to deal with this, but I dont know it.

eweb101 · 08-04-2019, 11:31

I just got the pump back from fuel shop. The problem was the #10 o-rings which I don't think I could've replaced myself.

It cost more than I wanted it to but the leak stopped and the engine runs a little better at idle so can't complain.