What did you to reseal cooler?

 

Oil cooler o-rings get hard with age, part of "compression set". When it gets cold, they shrink and leak. Warn the engine up and they expand and stop the leak.

The cycle of expansion and contraction on an old o-ring is tough on them and will rapidly cause them to fail. With the oil cooler, this can spell big trouble when you mix the coolant with the crankcase oil. This problem should be repaired soon.

 

Crap, I shouldn't have read this thread, now mine is leaking.

 

Just got off the phone with Bob, O-Rings on the way! Can't thank you enough for doing what you do Bob, saved me time and money. Rep him for me when you can guy's!

Replacement O-rings for Ford Diesel Engines

 

very good write and perfect pictures. im ready to start on mine. thanx alot guys for
the help and info

 

This morning when I went to leave, as I was warming my truck up, I got white smoke. It cranked easily, on the first try. It has been cold lately, but only like in the 30s, not like -4 or nothing. After it warmed up it quit smoking, and didnt smoke the rest of the day. This evening when I got home I climbed under the truck not knowing what I would see. It looks like on both sides are leaking oil. If I go from the top there is nothing wet. If I go under I can see that below the exhaustg manifolds are 'wet'. It's oil, but could the oil cooler make both sides wet? I'm at a loss.

Theres no coolant in the oil, and no oil in the coolant (that I can tell). What the heck is going on??? It didnt do this until it got cold.

 

Both sides of the engine can get wet from a leaky oil cooler. If the oil cooler is leaking out of the front the oil tends to follow the crossmember, and pool in the depressions, and the airflow under the truck tends to blow it all over everything.

As for why its leaking, the O-rings have gone through so many heat cycles that they have lost their elasticity. When I did my oil cooler back in Nov. my old orings were very hard and very brittle. I could have re-treaded a shopping cart wheel they were so hard.

 

It happens to me too! and sure enough it was the O rings. they leaks when is cold and couple minutes after you start your engine, it warm up and seals temporarilly.

I buy a used oil cooler on Ebay, clean it, paint it and change the rings so when i take the bad one away I have the new one ready to go!

The folks at the dealership wanna charge me 1400 bucks to do it

https://www.ford-trucks.com/forums/p...ictureid=51138

 

These new advanced better quailty o-rings be have now helps a good measure but has anybody though of using a bead of hi-temp black Permatex around both o-rings itself for added measure. I t just sounds like a great idea. Might give it a whirl when mine gives up the ghost..

 

I said it once, and I'll say it again. I think everyone on here needs to rebuild there oil cooler due to the age of our trucks. I pulled mine cause it was leaking at the front block to oil cooler gasket, but when I pulled it apart, the green o-rings were so brittle and hard they broke apart with barely any pressure. Very easy job to do.

 

Not trying to burst anyone's bubble here, but that idea runs along the same lines as using RTV on transmission pan and valve cover gaskets.

DO NOT DO IT. Not only will the "sealant" not help the situation at all, but if you get any of it to actually stick to the o-rings, whatever is left over WILL find its way into the coolant passages and oil passages in the cooler.

Bad idea. Just use the o-rings as they come without adding any "sealant" to them. Feel free to lubricate them as you put the pieces back together (good luck pressing the cooler back together without any lubricant anyway), but don't use anything extra to help seal them.

 

cleatus 12r,

I must agree with you as I found some high temp silicone in my oil cooler from using some on my water pump R&R. It was not enough to cause a flow problem, but your point is well taken.

 

What are the earliest symptoms of coolant in the oil or oil in the coolant?

I know that water in oil whips into a gray colored mayonnaise, but is there a way to detect a leaking oil cooler before it gets this bad?

 

Very nice write-up Cody. This is one that I will print and put in my "How To" binder

 

Another reason for not using any sort of silicone is that the o-rings are designed to move - that's why you lubricate them prior to the installation - not just for the ease of going together.