• Hello there guest and Welcome to The #1 Classic Mustang forum!
    To gain full access you must Register. Registration is free and it takes only a few moments to complete.
    Already a member? Login here then!

Stainless brake lines and Dot 5

sigtauenus

Active Member
For the guys who have stainless lines and Dot 5, what is the trick to getting the lines to seat? I understand the Dot 5 will find a leak easier than Dot 3, and I still have a couple junctions that are weaping. Nothing heinous, but still needs fixed. Do I need to just keep loosening and tightening the fitting or replace the lines altogether? At this point I'm contemplating flushing the system a couple times with alcohol and going back to Dot 3 and seeing if that works. I'm hesitant to do that, because if the Dot 3 leaks too, then I have a mess with my paint (the reason I went with Dot 5 to begin with) and I still have to fix the leak anyhow. If its going to leak regardless, I might as well fix it and stick with Dot 5.
 
I bought a set of SS brake lines from Classic Tube and havent installed yet. Interested to hear solutions to this
 
You will find that the stainless lines will not deform to make the seal like a standard steel line will. In fact, when using stainless lines the part the line is joining will actually deform (like the caliper seat or the M/C seat). While I'm only using DOT3 (I'd like to go to 5 just for paint reasons), I had one helluva time getting everything to seal properly and my paint is ruined at the proportioning valve. Everywhere else sealed up fine though. I did as you mentioned, loosen the fitting and then tighten a little tighter, then loosen and tighten it even tighter. This basically "tweaked" the seat on the proportioning valve. Care must be taken to not strip the threads though, but gradually increasing the torque each time helps prevents that. No leaks since.
 
I never got the SS lines and DOT5 to mix. I finally pulled the stainless lines and went basic steel lines and DOT3. Not a single leak!!! Best move was to give up they never stopped leaking a little.
 
Well, I finally got the brakes leak free. I couldn't get to the distribution block with everything assembled, so I pulled the steering column, cracked the leaking connections apart and tightened again twice, and then gave it a run, and it was good. Brakes are solid, no leaks, works great. SS and Dot 5. Just was a PIA to get there.
 
I always run stainless lines on all our builds and silicone brake fuild with no leaks. I seat all lines before I put the fluid in. Rich.
 
Back
Top