new oiler cooler line leak at fitting
 

I just started the engine after replacing the oil cooler lines on the SD. The lower (tructec brand made in Germany) is leaking at oil cooler the fitting. Apparently the surfaces aren't mating as they are supposed to.

I disconnected the leaking fitting, checked both surfaces for contamination and reinstalled. I tightened as much as I was comfortable but didn't want to strip the cooler. I also turned the line as I tightened the nut hoping that it would seat better. (works on Cummins fuel injection line) It is still leaking.

Anyone have any sealant or methodology that would be acceptable?

This is a compression fitting and is normally installed dry with no sealant.

Clean both surfaces with one of those green scrubby things you use at the kitchen sink. Re-assemble.

Check the threads on the oil cooler fitting...you may have damaged a few removing the old line, very common on the w123....if that is the case it won't seal, you will need to install a new fitting....though some people have used jb weld on the fitting and then screwed and tighten the line...

The old fitting came off easily. I was thankful because they can be a pita. The original leak on the old lines was from the crimp.

W123 or W126 same set up, aluminum cooler threads and steel fitting for the cooler line fitting.

The sealing surface is the Ball and the Socket. Socket being the Cooler, could have a gouge in the surface not making the seal. or the ball end wasn`t machined well for the fit. As Kerry mentioned, a Scrubber might do the trick.


The threads don`t do the sealing, they keep it tight.
Using JB Weld will definitely seal it, but probably won`t come apart again.

If the old lined didn`t leak, I would guess it is the new line being the problem.


Charlie

I cleaned with scotch brite, then oooo steel wool and brake cleaner on clean rag. It still leaks.

The bottom line is the out to the filter. Would a very little black RTV be safe if applied to the ball? Is there something better? I have some Ultra Copper handy and JBWeld. I'd prefer not JB in case it needs to come apart.

Agreed, seal is the ball & socket.

^^ That would be a bad idea.

And what might be a good idea?

I've never had this type of joint refuse to seal. Cummins injector lines are similar with higher pressure. Usually, scotch brite and torq takes care of it.

Put a Copper Crush washer between the Ball and the Socket. You can get a Copper Washer assortment at Harbor Freight.

A Hydraulic Shop would likely have a Crush Washer if you explain to the how the sealing is done.

Heat the Copper Crush Washer till it is red hot and let it cool; that softens it.

Actually even some thick Paper Gasket Material with the appropriate sized hole in the Middle would work.

Using a different line would be a good idea. Absent any evidence that the oil cooler (male) fitting was damaged by recent work, then the machining on the new hose end is the likely culprit. No good in the long run comes from making a defective part work.

One of our other Members had the same issue. But, I can't remember the details.

Could it be that the Hose Hut is so deep that the Nut is hitting the Oil Cooler before the Ball does?
If that is the case if there is room and it can be done without damaging the Ball you could file the Nut down so it is not so Long/Deep.

I would be writing the Seller and Tructec an informative Letter about their Product and the problems it caused. It could be they would refund some Money.

I am speculating that the Nut that is on the Hose is too long. I just measured Nut from a W123 Oil Cooler Hose end and it is 1/2 Inch long.

If the Nut was 3/4 inch long the Nut might bottom out on the Hex of the Oil Cooler where you put the back up Wrench.

The nut isn't too long. There is plenty of room to get the back up wrench in. 3 out of 4 connections sealed. I thought the line may have been cocking so that the ball & socket didn't mate correctly.

I was careful to get the nut started and pull the ball back then move the line to see if it would seat in the nut better/straight. I can't tell any difference 1 way or the other.

I'll disassemble once more, clean & reinstall. Then, I'll use a gasket or washer of break down and JB it. I won't go to the trouble of pulling the line again unless it won't quit leaking.

I'm headed out to prep for a bike ride. We have ~600 riders coming to town this weekend & we need to be set up for registration which opens at 6:00 tomorrow. I'll even get to ride this year - 1st time in a long time.

Any other ideas? I think we've exhausted but....

I recently bought a Trcktec oil cooler line. I hope I don't have the same issue.

Even if you JB Weld it on You can still remove it. JB Weld is rated at up to about 250 degrees F; after that it starts to melt.