APD

Over the last few days when I start the truck it runs rough for just a second. Never did that before.
Driving yesterday, the idle sounded a bit lower than normal.
Went to start this morning, no start.

While staring at the engine, I notice fuel dripping from the IP about every 5 seconds. So obviously the fuel pressure is bleeding off when parked.

The drips are forming where the high pressure head meets the main body of the pump, and drip they drip onto the power steering pump reservoir.

I assume this is the big O-ring that seals the head to the body?

Can this be fixed without removing the pump?
What special tools, techniques, and precautions should I take?
Gotta have my truck for work, so Im hoping to do this as quickly as possible.

This is 1990 with about 300k miles on it.

cougar

Try tightening the bolts first. Sometimes it works, sometimes it doesn't.
Look in the FAQ's section at the top of this section. There is a lot of info on the VE pumps in there.

93-331-29psi

If I were to attempt this seal replacement I'd pull it off the truck, just because there'll be more room, it'll be less awkward to get at. You can stretch the o-ring around the distribution head, but I kinda question what that does to the integrity of the o-ring stretching it that far. If you do attempt it be sure to do the two screws at a time method and don't let them back all the way out. I tried to do mine on the truck and failed miserably! In my case though the pump had a broken pin on the cam disk/driveplate (I think that's what it's called) so it needed a rebuild anyhow. I learned my lesson and decided I'll let pump work to those who know what they're doing. Good luck

93-12Smoke

Very risky to try it on the truck.

Jim Lane

It can be done but you have to stretch the o-ring, not worth the risk, better to remove the pump and do it right.

APD

So from what I've read so far, I cannot pull the head completely off.
What Happens if I do? Will parts fall out?

What are the risks? Just stretching the O-ring? any others?

It looks like the technique is to loosen the bolts a little at a time, and pull the head back until the O-ring is visible.
What else do I need to know about?

93-12Smoke

Yes, parts will fall out or can become misaligned causing a more expensive failure. A damaged pump head will cost you about $800 to replace just that.

93-331-29psi

You'll mess up the entire timing of the pump if anything falls out of place. Definitely a huge risk. Like I said stretching can be done but ok the truck leaves the possibility of the o-ring not getting in the groove. Taking it off is only a 45 minute job.

APD

Ok I have replaced VE pumps on VW's, but not a Cummins.

If I take the pump off, and orient it vertically on the bench, and then remove the head, will everything stay together?

And If I replace the seal without rotating the pump, can I slip it back into the timing gear and everything should remain in time?

thrashingcows

My opinion...as always...is if you have the pump out to replace one or two O-rings....you may as well do the whole thing. I just don't see the point of only replacing a couple old O-rings that are failing...then have to do it again in 6 months or so when the next one fails. But this is just me.

I've tried to change the big O-ring with a spare IP on the bench. Just how you would be doing it on the truck. And I could not get the O-ring off without things falling apart inside the pump.

Once the pump is oriented vertically you can slowly remove the bolts and carefully remove the head. There are a couple big HD springs that may tip or fall to the side. There is usually a couple shims on the top, and bottom? of these springs. Just watch where they go.

Other then that, that is all that should move. You can then replace the O-ring and re-install. Make sure you lube the O-ring with some clean engine oil, or tranny fluid before you re-install. And watch the O-ring as your tightening it down. I use a soft/blunt end pick to push the o-ring in as I'm tightening it down. You don't want to fish mouth the O-ring and cut it off.

APD

Ok, having now done a head reseal successfully, there is no way you can do it on the truck.
Maybe it is theoretically possible, but you have know way of knowing if the springs have come loose, or if that little washer has become unseated.
The only way you know is by cranking the starter and risking damage.
And to get to the point where you can take the head off, you have already done about half of the removal job


Thanks for the good advice....now that I've taken the pump off (twice), its quite easy and quick.

93-331-29psi

Don't feel bad. I pulled mine 6 times because I couldn't get the **** thing started after putting a new IP on. Turned out to be a bad lift pump. Put a new LP on and it first first turn of the key. Live and learn right.