Sadly, I am having to start a thread for my HPOP leak. I've read about 15 of them, and it seems most people get lucky with having an o-ring go out.

So after a couple hours of cleaning and investigating . . . I pinpointed the leak to be coming from the VICINITY of the rear oil plug. Easiest one to pull . . . pulled it, and the o-ring on it was trashed . . . so I replaced it 2 days ago and figured all should be well.


Seems I'm especially lucky . . . the oil leak is definitely not as much or as big . . . but, I am still getting a leak. I honestly cannot figure out from where, but I am about 95% sure it is leaking from that big flat end next to the rear plug. The HPOP is wet just underneath that part, and the rest of the pump is dry everywhere else that I can tell. The "non-serviceable" plug doesn't seem to be wet at all, but it is hard to tell down there . . . but certainly it is still leaking, NOT from the rear oil plug, and almost certainly from that flat area which I'm not sure whether or not I can get something to fix it.


#1, does anyone know if this part is known to leak? Is it under high pressure, and if it is leaking, is it serviceable?

#2, if it is serviceable, where do I find whatever would be needed to stop the leak?


I'm really lost at this point . . . because none of the classic leaking points seem to be wet . . . and to further my discouragement, when I went inside the engine a couple days ago, I found 2 different wire plugs that were not connected. I found a unplugged fitting on the HPOP, and plugged the one that fit in there (must have come from there right?) and then I searched high and low within the radius of the other plug . . . cannot find where it came off of. It branches out of a thick mass of wiring right behind the HPOP and has a small metal clip that swivels on the end of it. It runs 2 wires . . .

And it does NOT clip into the HPOP next to the rear plug because an identical plug is plugged into that one. Ideas and help please?

 

Are you talking about the large plug held in by a snap-ring? It has been known to leak, but very rare. There is an O-ring in there that can be replaced. I noticed mine seems to be a little wet too.

 

It is pretty hard to find HPOP leaks sometimes because of the airflow that seems to push everything towards the back. Easiest thing would be to just get the HPOP kit and then start replacing till its gone, IMO. I thought mine was leaking once also, but it turned out to be the IPR.

Riffraff Diesel: HPOP o-ring kit w/ 7 o-rings

 

The large plate on the back of the HPOP is low pressure, therefore it is a VERY RARE leak indeed.

You say that you replaced the rear plug o-ring but did you use the proper LocTite compound? The LockTite 680 retaining compound is the correct sealing compound for the HPOP but you need it to setup for a couple of hours before starting the truck to allow time for it to begin curing. The o-ring does only 40% of the sealing, the LocTite does the rest.

If you used regular LocTite threadlock, the blue will not seal and the red will fuse the plug to the aluminum body and when you try to remove it, usually you destroy the HPOP.

As Clay said, the air flow will move the oil around and make it difficult to find the leak. It will usually push it to the rear of the HPOP and allow it to collect on the lip for the large snapring. A telescoping inspection mirror and flashlight sometimes helps.

 

I would take the HPOP out. Not really too difficult...time consuming because of the orietation of the HPOP mounting bolts but something that can be done with a little patience, a decent set of tools and the correct o-rings.

I replaced every single o-ring I could while I had it out of the truck. Removing the HPOP also allowed me to clean it throughly and double check for any leaks. The rear plate o-ring is easy if you have the right size snap ring tool.

I am going on two weeks with zero leaks so far. But I was **** about making sure I cleaned the threads on everything and applied the locktite compound. The exception to this was the IPR due to a port opening in the threaded region of the sensor.

 

Huh, I thought I posted a reply yesterday . . . don't see it.

Anyone think this is trouble: I put loc-tite 680 . . . right stuff . . . but the two lines were connected because they are dry, thus not the problems, and they keep a vacuum in the HPOP I think. I pulled the rear plug, but the oil kept seeping . . .

After 30 minutes of oil still seeping out . . . I just wiped it and threaded the plug back in. But of course by the time I had it there and began the threads . . . the oil had reappeared. So, could this have compromised the seal of the loctite? I know it says make sure it is dry before applying. The rear plug threads were dry, but the hole was certainly wet. Maybe this is the problem. If it is . . . how do I keep it dry? Pull the two lines and hope there is no more vacuum?

 

I would say you found your problem. Any time it says to clean the threads, it means both sets, male and female sides.

 

I sincerely believe whole-heartedly, that THIS is the secret to success in eliminating HPOP leaks.

I believe the o-ring is still there because it's just part of the original design.

The LocTite does the real job.

H&ll, I used the wrong type and it's still holding, but I was REAL careful about cleaning any oil residue off all the threads.

Of course, YMMV.....

Pop

 

Could someone confirm or advise on how to prevent that oil seepage for hours?

If I pull the two lines on the side out, will that eliminate any vacuum . . . and all the oil will come out?

Otherwise I think the oil will seep out for 4 or 5 hours at least.

 

Not sure what you're asking. If you're going to open up the HP oil system, it's wise to go ahead and suck out the HPOP reservoir as much as you can. Even then, you'll get some drainage out of where ever you're opening it up. At least for a short time. But if you get most of the oil out of the reservoir being the high point of the system, you'll save at least a quart or so of oil.