The Stovebolt Site Forums The Shop Area Engine Shop brake line problems

i "blew out" a front brake line and decided to have the local napa store make me one to replace it. it leaked on both ends, at the hose and at the master cylinder. i thought it may have not been flanged correctly so I broke down and order a whole set. i tried to replace that same line again with one from the new set and itleaked on both ends as well. the brake hose and master cylinder are new however the block to the back of the mc is not. the connections were not leaking prior to the line rupturing. the connections on the new lines are brass. the connections on the old lines do not appear to be brass. is there a sealant that can and should be used or do i have other problems? I have not attempted to replace any of the other lines since i am having problems with the first one. Any ideas for a solution?

i guess i should have identified the vehicle - 54 chevy 1/2 ton.

papa ed,

I don't have a specific answer as to why your lines are leaking. I will say this, these fittings are a pure mechanical seal/fit. No goop or sealant is required or recommended.

If both male and female fittings are of the same style, the system will not leak.

Stuart

I recall something about stainless steel brake line ends being flanged at a different angles than stock lines. Any chance someone had upgraded your truck with SS connectors & lines, or that you ended up with a SS replacement kit?

That could explain a poor fit and the leaks you're seeing. Maybe buy some brass connectors at the parts store and compare the angles to the non-brass ones on your truck?

-Boyo

I got a set of Stainless Steel lines from Classic Tube and they worked very well. I did have a dribble problem because they weren't torqued down all the way (that'll teach me to assume things!), but after I fixed that, they worked like a champ!

So, try adding a little more torque to the party and see if that stops the leaks.

You might try getting a single flare tool and maybe widening out the flare a little bit.

I recently redid half of my steel fuel line so that I could put a filter on, and I found that the flares work best when the flared ends overlap the fittings by a little bit. they seal up really nice and work like a champ.

Good luck!

steel lines are double flared,,,the line is bent over to the center of the tube then flared out so the line end is flattened on itself in the flare to prevent line cracking in the flare,,your mention of brass or copper in the line should not be,,not in the line in a brake system...doc

I agree with Brendan M (for stainless lines in particular and for regular lines). You can and should torque down on the fittings. Also try tightening and then loosening and then retightening the fittings. That will seat the double flange to the correct angle.

These are the instructions given to me by In-Line Tubes for all new stainless lines on my '54 Suburban. They all leaked at first and then they all sealed after following the above procedure (the one on the Master Cylinder was the hardest to deal with - I still get a drop or two leaking out over a month's time).

boyoconnor - the lines are the original steel lines that came on the truck - doc41 - the lines are steel but the threads are brass or at least they are a shinny brass colored metal of some sort - brendanm and tclederman - i believe i will run with your advice and get a little more muscle power behind my wrench and also back them out a few times. i hope that is all there is to it. thanks to everyone that has responded. it will be a weekor two before i have a chance to try again. it is somewhat reassuring that a couple of you have dealt with new lines that leak and that you have solved the problem - hope i can say the same! thanks again!

papa ed , don't forget to use a line wrench also. Save on some rounded corners.

What acwhite said.

Those tubing wrenches are the bees knees when it comes to brake lines...

i did not use tubing wrenches the first go around but you can bet i will have some for this next episode - afraid i have already rounded one a bit with the open end - hopefully i can salvage it. thanks again for all the advice and ideas.

try useing teflon tape

doc41 is right stay away from brass or copper fittings. Trouble with a capital T. Most part houses (it they re-ordered stuff when sold) will have dbl. flare fitting steel brake line in sticks ranging from 6" to 6' all you need is a bending tool.
A tip on using a bending tool, cap one end (rubber plug or cap) of the tube and fill it with sand cap it off the other end and use the bending tool. It makes for much cleaner and sharper bends with out collapsing the line. Oh and clean it out well before you install it.

Hey it just occured to me that japaneese and european connector nuts are dyed green or a pinkish color as they are differant thread pitch (metric). Do you maybe have metric fittings?
"the connections on the new lines are brass."

toyvo - i ordered them from our sponsoring vendor so i dont think they would be metric and maybe they are not brass threads after all - may only look that way due to their color. i did not realize as others have mentioned that they really need to be cranked down to "seat" the flange good. again, i hope that is all that is wrong. thanks for the info on the bending tool. i started to make my own but i don't get to work on it very often and i was trying to speed things up a little bit.

papa ed, where is whitesboro tx. I am in Nacogdoches. (east texas) Where men are men and sheep are scared. Also where most of the people you meet are related to you.

The ends are steel with a anodized coating. I would torque the ends down more, but don't try to use any type of sealer. If they don't stop leaking take it back off and look at the ends of the line, you should be able to see if the flare is still in good shape or has been damaged.
If their damaged have someone reflare them with the correct double flare.

wrong, no sealers on any kind on flare fittings.

toyvo - whitesboro is between sherman and gainesville on hw 82 - only 14 miles to the okla border. only been in texas 4 years - previously an okie but not from muskogee!!!!!!!!!!