Gentlemen, I have an 84 GSL-SE with the large oil cooler up front of the radiator. Can't seem to get the hose fittings to seat well enough at the oil cooler to not leak at RPM. I've put all the torque that I dare on the fittings with the appropriate wrenches and I just can't get'em to seal. Any tips on how to stop these fittings from leaking at the higher oil pressures associated with higher RPMs.
HELP!

 

Are you sure that the leaking is at the connection itself and not a crack somewhere close to it? I can't remember off the top of my head, but are there washers on the ends of the hoses? If so, make sure they are on.

Mike

 

Is it a threaded fitting? You might try to put plumbers/teflon tape around the threads on the oil cooler, than tightening the line down on it again. It fills the gaps between the male/female connection as you tighten. It's worked for me on radiators before.

 

The oil lead is not coming from a crack. We've examined it very closely. The fitting is a flanged type and the leak is not coming from the threads. It appears that although I've tightened down the fittings, the flanges are not sealing as a drip develops behind the hose connector where it swivels on the end of the hose. Both are leaking in the same place.

 

If the flange fittings use crush washers, then if you torqued them down all the way, they will leak. Start with new ones and barely tighten them down. Then start the engine and gradually tighten them to the point where they don't weap. Then raise the psi (with rpm) and check for leaks. Re-tighten if necessary.

 

The crush washers are on the fittings between the actual aluminum oil cooler and the adapter that the hose fitting fastens to. These washers are not leaking they are sealed nicely.

Should one use a sealant on the faces of the flanges to help stop the leak?

 

Are these AN fittings?

 

I think that this is the standard 45° SAE fittings. The cooler is a new OEM oil cooler and came with what appear to be standard SAE fittings. Both hoses from the engine to the cooler are not the standard hose but an aftermarket with metal braid. Didn't look to ensure that the hose and fitting are both SAE and not an SAE/AN mismatch. Although I wouldnn't have thought that the case.....

 

when i had my SE i went to the junk yard and got a 88 gxl oil cooler, bolted right up. i think it might be bigger.. heres a pic

 

I built my own stainless steel lines with fittings and lines from Jegs. I used both the lubricant and sealant that they offered and it made assembly a snap. I found that I had to crank pretty hard for the final turn when screwing on the AN fitting to the braided line. Perhaps you should try tightening the fitting more onto the line itself or your line may be in need of (more) sealant? Where did you get your lines from? Were they preassembled?

 

You cannot apply excessive force to tighten the fittings on a Se cooler. That is the #1 reason that the bungs on the SE cooler get cracked in the first place.

Sealant is not the answer either.


You need to make sure you are using the factory Aluminum crush washers. If it does not seal with those then you have other issues with your hoses.

 

His aluminum crush washers are fine.

To the original poster, your stock hose fittings have gone bad. Rust can sometimes develop at the swivel and work its way inside to the 45° AN style flare. Or the mechanical connection between the nut and the barb can leak. I had a pesky short/upper hose that would leak at the cooler. It appeared to be somewhere at/under the nut. I swapped the hose and the leak stopped.

 

Just to clarify, I was talking about the installation of the fitting onto the actual stainless steel line. I whole-heartedly agree that you have to tighten the fitting onto the bung of the cooler with extreme care.

I think that Jeff's right. New lines may be the way to go. If you have enough line, you could just remove the AN fittings and cut the ends of the stainless and install new fittings. Jegs was pretty cheap for both the fittings and the lines. And I had my shipment to my door (in Canada) within three days.

 

I was looking at a RacingBeat SE Oil cooler hose set and they don't come cheap. The set I was looking at was just south of $200; but claimed to be more inexpensive than OEM equipment. What say ye? Would hate to drop the cash and still have a leak....

Also, given the talk of the cracked bungs, I'm not sure that I want the RB setup if I have to replace the male fittings. All I need is to crack a bung on a $500 cooler and get to start over!

 

Look at trochoids cooler conversion thread, he (and others), made their own lines/ had a hydraulic shop make them. You just need good fittings. Can get fittings for decent prices from a couple places.

 

Check out Jegs.com. Six feet of stainless steel line is $40, ten feet is $63. For the #10 AN fittings: a straight one is $10 bucks, 45 degree is $20, 90 degree is $22. Assembly oil and sealant pkg. is $8 bucks. If you're worried about scratching the anodized fittings (like I was) than an aluminum wrench is $10 bucks. Cutting and assembly is a snap. Plus they look great.
Racing Beat charges a small fortune for the exact same thing. Plus, Racing Beat uses Earl fittings that are inferior IMHO as Jegs' fittings still swivel, even when tightened down.

 

As a little reassurance, you can save that $500 dollar Oil Cooler if you do crack the bung.

I don't know how many welding shops with do this for you since I just did it in my Welding Class at the college.

But, you can have some one TIG weld the crack closed and reinforce the bung, it doesn't take a long time to actually do. But the biggest problem is going to be cleaning the oil cooler out. You need to drain all of the oil you can out of it, and even then there will probably be a ton more than spews out once you start welding, I know this from experience.


Anyways, I figured I'd let you know that in case you do crack the bungs on the cooler so you don't feel like you now have a $500 piece of aluminium.

 

What my friend Sam (dj55b) did with my cooler was use a female to female AN adapter, cut it in half, cut off the oil cooler flange, and weld on the halved adapter. No more cracking aluminum flanges from overtightening. Haven't had a leak since.