Leaking Brake Line fittings

2345 Views 33 Replies 20 Participants Last post by ss27, 6 mo ago

J. Doug

Discussion Starter · May 13, 2022

Can somebody tell me please how to fix my leaking brake line fittings. I've replaced all my old broken and rusted lines with new. The line from the master cylinder to the rear is stainless. The others are steel. The left front leaks like a sieve at the hardline to flex line connection. The rear also leaks at the 1/4 inch hardline to flex line t fitting. I've tightened and retightened all the fittings, I'm afraid to put much more beef into them for fear of stripping the fittings. All advice would be appreciated. Thanks.

1 - 20 of 34 Posts

R66

· #2 · May 13, 2022

SS lines are difficult to properly double flare. I assume you have carefully inspected the fittings and flares for defects, they have to be perfect. They make a nickel washer that fits in the fitting to resolve sealing issues. I don't know the technical name nor part numbers, but do some Google and you'll find it.

SY1

· #3 · May 13, 2022 (Edited)

J. Doug said:
Can somebody tell me please how to fix my leaking brake line fittings. I've replaced all my old broken and rusted lines with new. The line from the master cylinder to the rear is stainless. The others are steel. The left front leaks like a sieve at the hardline to flex line connection. The rear also leaks at the 1/4 inch hardline to flex line t fitting. I've tightened and retightened all the fittings, I'm afraid to put much more beef into them for fear of stripping the fittings. All advice would be appreciated. Thanks.

Doug, Earl's makes these seals. I haven't personally used these but look similar to the Seco Seals I used on jet engine and thrust reverser stainless steel flared AN 37 degree fittings. Earl's states theirs are for AN fittings, if true they are 37 degree flare conical seals. Keep in mind automotive are typically SAE 45 degree fittings and always double flared for fuel and brake systems (the tube end is folded back inside itself then flared, pretty obvious looking at the inside of the flare end). I have not seen a conical seal for SAE, but these are so thin and soft they may work? The Seco Seal is basically a crush gasket to seal minor imperfections or scoring on the flare. Not to seal mixing 37 and 45 degree fittings, which sould never be done. That said automotive "should" be 45. See what the others say here. I have seen numerous single flared lines that the flares were cracked. Stainless is very difficult to double flare even with my good Snap-On double flare kit.

Font Circle Gas Auto part Aluminium

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SY1

· #4 · May 13, 2022

R66 said:
SS lines are difficult to properly double flare. I assume you have carefully inspected the fittings and flares for defects, they have to be perfect. They make a nickel washer that fits in the fitting to resolve sealing issues. I don't know the technical name nor part numbers, but do some Google and you'll find it.

BTW start my seeing if you have an aligment issue first the require rebending. Tube and fitting need to be perfectly aligned before tightening, not drawn together to force it to tighten. If flare is cracked, scored badly, distoted or poorly flared (not enough material flared or offset material flared), discard it and get another line. These seals are really just for minor scratches.

Vega$69

· #5 · May 13, 2022

These will work an 45* brake lines.

www.amazon.com

Parker 2GF-3-pk20 45 Degree Fitting, Flare, Brass, Flare Gasket, 3/16" (Pack of 20): Amazon.com: Industrial & Scientific

Parker 2GF-3-pk20 45 Degree Fitting, Flare, Brass, Flare Gasket, 3/16" (Pack of 20): Amazon.com: Industrial & Scientific

www.amazon.com

Reactions: 1

R66

· #6 · May 13, 2022

As SY1 said, alignment is critical along with defect free fittings and flares. These nickel seals are used by the nuclear industry in extremely high pressure hydraulic lines. They work. I think Vega$69 has your source.

timkeller

· #7 · May 13, 2022

I would use the flare washer Vega$69 suggested. I used one on my stainless fuel line to carb that wouldn't stop leaking and it fixed it.

SoCal805

· #8 · May 13, 2022

+3 on the copper flare washer....assuming the flare angle of the opposing lines is =

StevieBB54

· #9 · May 13, 2022

I made new lines and they are a biotch especially SS tubing. I spoke with some old colleagues and builders and they tell me the best way to make flawless double flare ends is using those $200-$300 flaring tools. My Snap On one was a PITA unless I used that malleable brake line tubing. Good to see they have conical sealing washers.

Sauron67MM

· #10 · May 13, 2022

None of my original lines leak even when reused. Nor do any of the ones on friends collections. Rust free original lines are fine even after r&r. Not sure the obsession with stainless brake lines. Most people don't drive their cars often enough to worry about it.

I bought one of my cars in 1984. Original lines. No leaks. I drive it in the wet weather and like I hate it. I use Ni-Cop now with a pneumatic flaring tool. Easy.

J. Doug

Discussion Starter · #11 · May 13, 2022

Thank you all for your suggestions. I'm leaving for an extended Harley trip, so I will address this dilemma when I get back at the end of the month. I have purchased a new flaring tool and also a lapping tool from Koul Tool. So hopefully with your suggestions and the new tools the leaks have no chance of continuing.

chicoman

· #12 · May 13, 2022

Use the copper flare gaskets

Reactions: 1

jimsl78

· #13 · May 13, 2022 (Edited)

There's a trick to getting SS flares to seat. First off, all those suggestions for checking the quality of the flare, and alignment are important, do all of this before you resort to using copper or alum seat washers. When initially tightening SS fittings go easy, start with light tightening and loosen. re tighten a little further and loosen, progressively go a bit further each time.

Reactions: 2

nashcar

· #14 · May 13, 2022

I had a problem with one fitting when installing SS lines. I carefully cut a thin piece of 1/4” copper tubing and placed it in the fitting. Tightened up and solved the leak problems.

Vega$69

· #15 · May 14, 2022

Sauron67MM said:
None of my original lines leak even when reused. Nor do any of the ones on friends collections. Rust free original lines are fine even after r&r. Not sure the obsession with stainless brake lines. Most people don't drive their cars often enough to worry about it.

I bought one of my cars in 1984. Original lines. No leaks. I drive it in the wet weather and like I hate it. I use Ni-Cop now with a pneumatic flaring tool. Easy.

Actually Stainless Steel lines are better than steel for cars that are driven often.

My 1st ProTour build I made up all stainless steel lines. Bent steel lines 1st and used them as a template for the SS lines. PIA. Every build after I use NiCad. easy to work with, no leaks. I hit them with steel wool and they polish like SS very easy.

For your leaky SS lines the copper washers will fix it.

Reactions: 1

SY1

· #16 · May 14, 2022

Vega$69 said:
These will work an 45* brake lines.

Parker 2GF-3-pk20 45 Degree Fitting, Flare, Brass, Flare Gasket, 3/16" (Pack of 20): Amazon.com: Industrial & Scientific

Parker 2GF-3-pk20 45 Degree Fitting, Flare, Brass, Flare Gasket, 3/16" (Pack of 20): Amazon.com: Industrial & Scientific

www.amazon.com

Thank you Vega69. This is going into my notebook now!

SY1

· #17 · May 14, 2022

jimsl78 said:
There's a trick to getting SS flares to seat. First off, all those suggestions for checking the quantity of the flare, and alignment are important, do all of this before you resort to using copper or alum seat washers. When initially tightening SS fittings go easy, start with light tightening and loosen. re tighten a little further and loosen, progressively go a bit further each time.

Good point! Stainless fittings and hardware too seem to gall going together dry.

J. Doug

Discussion Starter · #18 · May 14, 2022

So after reading all these suggestions i'm seriously thinking about ripping all the SS lines out now and going NiCad. First I'll see if I can get everything to seat first.

emdoller

· #19 · May 18, 2022

Sauron67MM said:
None of my original lines leak even when reused. Nor do any of the ones on friends collections. Rust free original lines are fine even after r&r. Not sure the obsession with stainless brake lines. Most people don't drive their cars often enough to worry about it.

I bought one of my cars in 1984. Original lines. No leaks. I drive it in the wet weather and like I hate it. I use Ni-Cop now with a pneumatic flaring tool. Easy.

Amen brother!!!’

camlinebilly

· #20 · 6 mo ago

I purchased new ags preflared line and unions and i get leaks everywhere! upon inspection of the unions i found that they all seem to b different (bad quality control) in height in the union. also the lines have a small ridge that scores the unions everytime.

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