Brakes: Stainless steel brake lines

[Skip Lackie]

Although the vehicle in question is not a Studebaker, I believe the question (and answers) apply to nearly all old cars, so I am posting it here under Tech Talk. Clark can move it to Stove Huggers if that's more appropriate.

I am replacing nearly all brake components, except for a few short under-hood brake lines, on a 70 Camaro with front discs. Because they are the correct length and pre-bent, I bought a complete stainless steel brake line kit from In-Line Tube. All but one piece fit well. The one that did not fit was replaced by them at no charge, using my old one as a pattern. Here's the problem: a couple of the SS fittings continue to weep a bit of fluid, despite being tightened to the point that I'm afraid I'll strip the threads. The one that is the biggest problem screws into the proportioning valve, which appears to be brass, and presumably is softer than cast iron.

I have heard that the SS brake lines are lot harder and therefore more difficult to get to seal securely. If so, what is the solution to the problem?

[sweetolbob]

The ones into the brass should be the easiest to seal as there is generally a domed area for the flare to seat into. If you are not close to driving it, and I'll bet you are not with leaking brakes, I'd open up the weeping joints and look for deformation or gouges in the flare. It doesn't take much with SS as you said it is hard.

If you don't see any issues, you may want to take a flaring tool and be sure the flare is as it should be and not slightly deformed by doing the last step in making the flare again.

If all that looks good I'd go back to Inland and talk to them. I wouldn't try to use sealer on them although you may want to lube the threads with brake fluid when you put them back together to help with tightening.

HTH, Bob

[rootbeerstude]

Stainless tubes are much harder and generally will leak if attached to used items( prop valves, wheel cylinders, etc) The brass seat inserts will have a groove formed from the original tube and the new tube won't match up. Being harder it can't comform and seal.
The solution is to use the OEM steel tubes.
Also silicone fluid seems to leak more so than DOT 3, don't know why.

Steve

[Dan Timberlake]

So far 100% of the SS brake line installations I know about ( yours, and a buddy's Corvette) have had multiple issues with sealing. Not to mention the larger tubing is stiff and disagreeable.
We "touched up" a few of the flared tubing seats that insisted on leaking. As supplied they looked awful when inspected with a little maginfication. I'm sure many of the non-leakers probably looked pretty bad too.

I consider this the ultimate brake tubing material.

http://store.fedhillusa.com/?gclid=CPeooPCujLoCFQ6k4Aodxz8A0A

My last dozen or so cars have had it factory installed. It looks GREAT even after a decade or two of salty Massachusetts winters.
My 2 buddy's US made pickups needed front to back line replacement at that age.

NAPA often has it in 25 or 50 foot coils.

[Skip Lackie]

So far 100% of the SS brake line installations I know about ( yours, and a buddy's Corvette) have had multiple issues with sealing. Not to mention the larger tubing is stiff and disagreeable.
We "touched up" a few of the flared tubing seats that insisted on leaking. As supplied they looked awful when inspected with a little maginfication. I'm sure many of the non-leakers probably looked pretty bad too.

I consider this the ultimate brake tubing material.

http://store.fedhillusa.com/?gclid=CPeooPCujLoCFQ6k4Aodxz8A0A

My last dozen or so cars have had it factory installed. It looks GREAT even after a decade or two of salty Massachusetts winters.
My 2 buddy's US made pickups needed front to back line replacement at that age.

NAPA often has it in 25 or 50 foot coils.

Thanks. I used the Fedhill cupro-nickel brake line on my 54 3R6, but that was a frame-off restoration where I made up nearly all the brake lines myself. It's a lot easier when there's no body in the way. The Camaro is simply undergoing a mechanical freshening up, and I figured if I was gonna replace the wheel/master cylinders/calipers and hoses, I might as well replace some of the other 40-year-old brake components at the same time. The car is just up on jack stands and is complete and ready to drive except for the brakes.

The big tubing companies (Right Stuff, In Line, etc) all offer complete kits, pre-cut, pre-bent, and with the wire wrapping in all the right places, for common popular cars like Camaros, and it's very tempting to just send them a check and not have to worry about all that repeated measuring and crawling around on the floor like a serpent. In retrospect, I should not have chosen the SS tubing, though it sure does look nice.

[Skip Lackie]

The ones into the brass should be the easiest to seal as there is generally a domed area for the flare to seat into. If you are not close to driving it, and I'll bet you are not with leaking brakes, I'd open up the weeping joints and look for deformation or gouges in the flare. It doesn't take much with SS as you said it is hard.

If you don't see any issues, you may want to take a flaring tool and be sure the flare is as it should be and not slightly deformed by doing the last step in making the flare again.

If all that looks good I'd go back to Inland and talk to them. I wouldn't try to use sealer on them although you may want to lube the threads with brake fluid when you put them back together to help with tightening.

HTH, Bob

Bob-
Thanks -- it does. Some day, I'm gonna do a brake job where I only have to bleed the brakes ONCE.