Nother top end oil leak on my PSD...grrr

[paulkeith]

Dammit.

I did my high pressure o-rings back in fall of '06. Started leaving puddles of oil again, checked the intake valley, sure enough, full of oil. THINK I've tracked it to the hpop to hpop reservoir gasket. I had the intake spider off 3 times in 3 hours. Annoying.

I'm ordering the gasket tomorrow and just ordered the high pressure line disconnect tool. Looks like this coming weekend is shot

any of the rest of you 7.3ers had hpop leak issues or removed the pump?

[Lucky Jeff]

It seems to be pretty common. I have plenty of friends with PSD's and pretty much all of them have messed with the HPOP at some point because of a leak. I've played with those things a bit when we're all hanging around in the shop. They confuse the hell out of me. Easy to do though since I own a simple mechanical 12 valve Dodge.

[paulkeith]

times like this i wish i had a mech. 12V 6bt. probably the greatest diesel ever made. except for the 6.5L GM of course.


Since I made this post, I replaced the hpop to hpop reservoir gasket. As soon as I had the old gasket out, I realized it wasn't the problem, gasket was in flawless shape. I made the run up to TN for the windrock trip and back, and the truck left a 4" oil stain within 20 minutes.

Re-diagnosed and traced it this time to a plug on the hpop that ford calls non-serviceable. After a little more digging, I uncovered an IH repair kit intended for the hpop on the DT466 that apparently had similar problems. With a leak from this plug on the T444E, ford manuals say to replace the pump....but for the same leak on the 466, IH provides a repair kit. At $45 instead of $600, I'll try this repair kit first.

Apparently the issue is that the plug that is leaking is a steel plug and the hpop housing is aluminum. I've heard a lot of horror stories that when people go to remove this plug, the aluminum housing threads come right out with it. The IH repair kit instructions say to heat the plug to 4-500*F to break down the assembly loc-tite and then turn the plug out. Also heard that a very large number of HPOPs were manufactured incorrectly with the holes too large and that results in eventual leakage. Apparently this repair kit replacement plug is slightly larger to engage the aluminum housing more.

We'll see what happens. If i fubar the pump, the truck will be down for a week+ while I wait on a new hpop....and i'll be out $6-700 as my old pump will no longer be a quality core.

Sigh.

[Lucky Jeff]

we just had to make that plug for a friend of mine because his did the same thing. We decided to just make one that had twice the amount of threads on the plug and tap into the hole. There is a lot of excess aluminum down there and they just decided not to tap it in any further. Seems to be holding fine. But we still don't have the truck running yet from the motor swap.. Ran once and haven't gotten it refired . Pretty sure it wasn't our pump work because it wasn't running before that anyways.. Gets pretty frustrating that's for sure. Diagnosis sessions turn into sessions

[paulkeith]

Its a complicated system with a lot of places for failure to occur. My main worry with the pump is if that plug lets go while running, you're talking about emptying 15qts worth of oil pan within seconds.

[paulkeith]

Finding this thread - pretty hilarious.

Because.

The IH kit solved this subject leak above for about 4 years - just this past Saturday it started pumping oil all over the driveway again, from this port again. I found chunks of the o-ring pushed out.

So the deal is pretty much what I laid out before - the threads are cut like shit in the pump, tolerances are garbage, the OEM plug engages too few threads and eventually it leaks.

The "repair" plug has double the threads:



So, repeat the same work this time - $30 for a new gasket, $5 for o-rings and loctite 680 (bearing retainer compound) from mcmaster.

Here's the condition of the threads inside that port:



This plug holds ~3000psi ~2-300F engine oil any time the engine is running. Top notch machining, right?




New "extended threads" plug matches the full threaded depth of the pump:




So, new o-ring...Viton -903 90A durometer:



The 7.3 crowd recommends applying the loctite manually to the female threads rather than just the male threads because the rough condition of the threads may scrape the loctite off entirely as it goes by, so apply to both:




Torqued to 75lbin:


Baking under a hot halogen (loctite 680 cure is accelerated by temp - http://tds.loctite.com/tds5/docs/680-EN.pdf)


Last time I did this was on the floor of my garage with oil almost guaranteed to be seeping into the threads as I torqued the plug - and that held for 4 years. So hopefully this is the last time I have to fk with this port. Fingers crossed.

[BigDaveZJ]

I just got done doing the non-serviceable plug on mine as well. Major PITA but it was peeing oil out of there like crazy.

[rstrucks]

I looked all over my 12v and couldn't find the HPOP. Hmmmm, that's strange, musta fallen off.


Just kidding. When my POS truck falls apart around the drivetrain, I'll probably look for a 6.0 F-250 in need of an engine (or lots of expensive engine work) and swap in a 12v. Then I'd have a nice truck with the engine I have grown quite fond of.

[paulkeith]

I looked all over my 12v and couldn't find the HPOP. Hmmmm, that's strange, musta fallen off.


Just kidding. When my POS truck falls apart around the drivetrain, I'll probably look for a 6.0 F-250 in need of an engine (or lots of expensive engine work) and swap in a 12v. Then I'd have a nice truck with the engine I have grown quite fond of.

Funny guy. I wish I could fire back with a VP44 joke but I can't even do that.

Considering this is my 6th top end oil leak in as many years, I'm getting pretty exhausted with the ol 7.3. Paranoia each time I walk out and instinctively check for an oil stain underneath. On the upside I'm getting pretty quick at tearing the top of the motor apart.

The truck and drivetrain around it is of course aging like a champ....so I've definitely spent a few hours this week perusing destroked and reading some fummins threads. Figure I could probably get a 12v done nicely for about $4-5k depending what kind of deal i could find on the 12v, but until the 7.3 makes a window where one doesn't belong there's no way I can justify that.

I'll just keep my stock in Viton, Brakleen and Scott's Shop Towels in the meantime.

I just got done doing the non-serviceable plug on mine as well. Major PITA but it was peeing oil out of there like crazy.

Glad it is indeed serviceable. Here's to hoping yours outlasts my first attempt..

[ZJ TINS]

Before you do anything buy a tap a chase the internal threads until they are smooth and nothing comes loose.
For a thread to work the lands have to meet to apply the right stresses so the bolt stretches.
Or take it to a machine shop and let them chase the threads.