Jeff N.

Assuming there is no corrosion damage, is rebuilding this unit as simple as:

1 - pull unit
2 - replace 2 o ring seals
3 - re-install with new washer seal

Is the access port accessible or will I need to remove lots of parts to remove the OPRV?

Any other hints or thoughts most appreciated.

Chris White

Step 4 - throw it away and repalce with one peice unit.

If you are having oil pressue problems its quite possible that the piston is sticking in the bore due to wear. Once the position of the piston is change the problem can get worse.

In my experience once the original 3 pcs oil pressure valve starts giving you problems its time to repalce it.

Euro951

I have two 1986 one piece units which I will let go for 40 each including shipping. In case you or any others need one. Barry

KuHL 951

Hopefully the OP already has the 1-piece conversion valve since there's no o-rings on the 3-piece. If he has the 3-piece I would toss it, buy one from Barry, and then replace the o-rings. The inner o-ring is tricky to get seated correctly on reassembly and can roll out of it's groove if not well greased when the two halves are pressed back together. You'll know right away when you start it though, no oil pressure. Be careful what o-ring sets you are sent, there's been a few suppliers send parts for the 87+ OPRV and they won't work.

Jeff N.

Chris - er...right. Glad I asked.

Barry - thanks. Can you hold one with my name on for a few days until I get this apart and see what's up?

Steve - will take it apart and see what's in there. Parts ordered via Pelican's site.

Question: The problem is slow build up of oil pressure (~10 seconds) on startup. Occurred when I installed the second oil cooler (series install, second factory cooler). Zero problems prior. Can anyone think of what else it might be? Trying to understand how installed part A (cooler) might have broken part B (OPRV).

KuHL 951

The OPRV's don't really break but usually get small debris that cause them to bind or form a bad seal. It doesn't take much to foul one up. My 86 all at once would not build pressure on start-up. I had he original 3-piece. There was a small bit of seal or coked oil stuck at the tip of the sleeve that kept the piston from sliding smoothly. I cleaned it out with carb cleaner and compressed air, it worked fine but I ordered a 1-piece conversion style anyway.

Dare

I'll take one of those. PM sent.

Jeff N.

Thanks Steve. That makes some sense - might have been a little piece to something that got into the oil system when I did the cooler work. Tried to keep it all real clean buuuuut.......

BTW, anyone have a better oil system diagram than this on Clarks? This one doesn't show the oil thermostat system and suggests all oil pumps thru the cooler cycle all the time. We know that isn't true.

Clarks Garage Oil Flow Diagram

eniac

Slow building oil pressure means the outer small O-ring is worn out, cracked, or missing. You can try putting in new seals however once the seals are worn, the OPRV is no longered centered and gets worn on the sides.

As a standard, I always replace them with the 1-piece unit. Why take the chance...

lee101315

I didnt have much luck repairing my three piece OPRV last year, I had an oil pressure problem upon startup every few days until I went to the updated one piece unit

Jeff N.

As this was sort of an instantaneous type failure - ie: worked great one day, was bad the next day after the oil cooler was installed - I'm hoping that I can just blow out a piece of crud and it will be good.

Really appreciate the help everyone. Thank you!

Report in a few days....

eniac

The crud is most likely the broken down o-ring seal.

Euro951

One OPRV is spoken for and paid, Thanks Jeff

The other is awaiting payment.

Barry

Jeff N.

OK. Having problems trying to get the new 1 piece unit installed. Turns out that I did have the old 3 piece unit.

Problem is that I can't get the threads to "take" in the oil housing so the plug will screw in. I've tried a variety of techniques but it's a hard place to get any feel. Little to no hand room. Combine that with a honkin' 24mm socket and 1/2 drive and it's like trying to do surgery with a club.

So, any suggestions on how to get this thing threaded in? I'm scared as heck of bunging up the threads in the aluminum housing.

BTW, are the "rolled" threads at the bottom typical? I looked at a new one pelican and this seems to be the way they are made...

Bri Bro

Do you have the alignment tool?