JB Weld for oil fitting?

I’m replacing the oil sump to oil filter hose, with the 9/16" fitting on one end and 5/8" fitting on the other. I tried the usual suppliers, but couldn’t find anything but a straight 5/8" hose. Any suggestions on a hose?

Absent a proper-sized hose, I was thinking I could turn up a sleeve on the lathe for the 9/16" fitting on the sump, then JB Weld it in place. Do you think it would work long-term, or do you think the JB Weld would break down after exposure to heat, pressure, and oil? If not, I know brazing would be better, but wonder if anyone ever tried JB Weld for this purpose?

When I installed my rebuilt engine 3 1/2 years ago, I found that one of the holes in the bell housing that held the clutch slave cylinder was stripped. Since everything was clean and oil free, I used JB Weld to repair the hole. I put some JB Weld in the hole and screwed the stud in and let it cure. My slave cylinder failed a couple of weeks ago and when I removed the stud holding the slave, the JB Weld still clung to the bell housing and the threads were still good. That’s a long winded way of saying that I would think that JB Weld would hold as long as the parts are clean when you apply it and then you allow it to fully cure before you attach the hose. The manufacturer claims that it can withstand up to 500 F., so the temperatures at the oil filter should be no problem.

A piece of ½" copper pipe (ID) will fit nicely and give you a suitable OD. Don’t know about JBWeld there - but the Cu pipe can be sweated with ordinary solder and propane torch. This will yield a solid connection.

A lip can also be added to the pipe by flaring it slightly or soldering on a ring. I cut the ring from the end of a 90° elbow fitting but some have used a suitable brass olive (ferrule) for that.

I used copper pipe as well for this exact application. There are three series of 1/2 inch (nominal) Cu pipe, all with exactly 5/8 inch O.D. Type K is 0.527 inches, Type L is 0.545 and Type M is 0.569. Can’t remember which I used, but I got a tight, slight interference fit. I beaded the pipe before fitting it, using a Parker beading tool. But the suggested flare or ferrule should work adequately.

Dave- don’t give up finding the correct hose. I have one I bought a couple years ago that has the diameter change molded into the hose. I think I found it at Rob Beere Racing but I don’t see it on their website right now. I’d contact them and any other suppliers before making a not easily reversed modification.

Doug, I took your advice. Thanks, and thanks to all who responded.

Classic Jaguar carries the hose. It’s a silicone hose they have made specially for XK engines. I just placed my order, so I won’t be needing any modification or JB Weld.

I started a thread on this a couple of weeks ago.

Type “L”, 1,2", is the pipe you want. A piece about 1.25" long is perfect. And the Ferrule is a nice addition to the end to keep the hose from slipping off, not that the hose has anywhere to go in this application.

I used JB weld.

Dave, What does Dan @CJ charge for the hose these days? Mine’s looking a bit aged.

I bet that’s where I got it- I’ve purchased several items form Dan


I wouldn’t use JB Weld in any situation that could result in catastrophic damage if it failed. Yes its a great product, but the cost of failure is so high that I would instead spend the money at machine shop etc to correctly fix the problem

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A valid point.

But, I did do some investigating prior to using the JB Weld and found on their web site:

Is J-B Weld resistant to water and/or gasoline?

When fully cured, J-B Weld is completely resistant to water, gasoline, and about every other petroleum product or automotive chemical.

I’m comfortable enough with it that I’ll leave it as I’ve done it. I’m always on the lookout for leaks (hate 'em) so I’ll just add looking at the fitting for signs of failure to my general list of things to check.

I paid $30 plus shipping for the hose.

And the UPS ground shipping fee to South Carolina for a 6 inch hose with 2 clamps was practically the cost of the hose again at $26.37. Their explanation for this was that’s how the UPS system they use works. Amazing. It’s a nice hose though.

I don’t doubt their claim, but I wonder how resistant it is to hot oil.

I’ve used various metal putties to repair a few things to good effect, but I myself wouldn’t contemplate it in this scenario.

Perhaps I’m just too cautious.

If I couldn’t source a correct part I’d make one from scratch. This wouldn’t be too hard, a disc of 1/8 thick brass and a copper elbow, some silver solder and a bit of time at the drillpress would be my solution.

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We are getting ready to find out.

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Greetings All,

I’m thinking that the very fact JB Weld say it’s “gas and oil resistant” tells me all I need to know.

Big difference between a “water-proof” watch and a “water resistant” one.

Not a good application for that product, which has good uses.

I have used jb weld to connect an external oil cooler to an atv engine. it is under pressure and has direct contact to oil, its been on there over 15 years.

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Thanks, John, re: financial management. Somehow, your original email via J-L got tossed as I was trying to reply.


Well, when have you ever seen a water-proof watch advertised? Nothing is ever water-proof other than in our minds, and advertising and product description use “water resistant” for liability purposes.

I would use it for sealing up the oil bypass pipe widener without hesitation (I sodered/sweated mine, which is I think a better approach). Failure here means, maybe a slow drip of oil, not a major problem…


Greetings All,

Personally, I’d go the route you mentioned.

JB Weld still an epoxy and it has limitations.