Brake bleeding
Moderator: redstangbob
Re: Brake bleeding
Still working on this, lol.
Turned out that some connections were too lose. I could stop the bubbles during bench bleed. But still had brake fluid leaking from the master during brake bleed. I finally made a little tool
and tightened the connector block to specs. Required more force than expected. So it should be sealed now.
However, now the angle is not good for the rear line:
Hard to see here but the brake line almost goes as high as the lower edge of the lid.
Is it OK like this? I would have to buy more connectors, with no guarantee that I will not end up at the same angle or worse.
Turned out that some connections were too lose. I could stop the bubbles during bench bleed. But still had brake fluid leaking from the master during brake bleed. I finally made a little tool
and tightened the connector block to specs. Required more force than expected. So it should be sealed now.
However, now the angle is not good for the rear line:
Hard to see here but the brake line almost goes as high as the lower edge of the lid.
Is it OK like this? I would have to buy more connectors, with no guarantee that I will not end up at the same angle or worse.
Since 1993.
Re: Brake bleeding
That's a clever tool. I always worry about stripping out that junction block. Do you know how much torque you put on it?
Based on your photo, it's not pretty, but as long as it's not leaking and there's no interference/rubbing on the line, I think it would be fine to run this way.
~Steve
Based on your photo, it's not pretty, but as long as it's not leaking and there's no interference/rubbing on the line, I think it would be fine to run this way.
~Steve
Re: Brake bleeding
Yes. I suppose you could use teflon tape on the threads and that might give you more ability to adjust the position of the block and not have any leaks.
1964 TBird Hardtop
1974 Porsche 914 2.0
1974 Porsche 914 2.0
Re: Brake bleeding
@sseebart, I torqued to 12 ft lbs which is the max amount according to manual. I'll proceed then, have to redo the rear brake line because it's too short for the different angle. The brake line junction behind the inner front fender will be really useful here.
@64ZCODE, when I couldn't get rid of the bubbles I did a test with teflon tape and it sealed immediately. In the end I didn't use it because 'the internet' said don't. Using it would have required extensive research.
@64ZCODE, when I couldn't get rid of the bubbles I did a test with teflon tape and it sealed immediately. In the end I didn't use it because 'the internet' said don't. Using it would have required extensive research.
Since 1993.
Re: Brake bleeding
A mechanic advised me once to use PTFE paste instead of tape. Since then, I've used it on all threaded connections that require some extra sealing. Easier than tape with fewer risks.
~Steve
Re: Brake bleeding
Every mechanic I’ve ever asked has strongly advised no tape; use dope or nothing.
When I had your same issue, Blab, I removed the tape I initially used (prior to being schooled) and it had degraded pretty bad. I did not end up using pipe dope, just tight seats, but that’s not saying I wouldn’t use it next time.
Bottom line, when I taped, I had seals that lasted a week. Not expert advice, Jmho.
Paul
VTCI 12014
Registry 45122
'64 Landau HT
"Beer, now there's a temporary solution!" ~Homer Simpson
VTCI 12014
Registry 45122
'64 Landau HT
"Beer, now there's a temporary solution!" ~Homer Simpson
Re: Brake bleeding
I made a new break line from the junction behind the inner fender to the master. Much better now, the old one was way too short. Time well spent.
Still leaking at the master / distributor block connection. Even with another quarter turn it wouldn't seal.
Not sure what I can do now beside buying a third master and another distributor block. Right now I'm so annoyed by the whole issue and the inherent problems of the parts or construction that I might just ignore it for now and let it leak and refill. Then convert to a dual master in winter. The more I worked on this, the more I saw where things can go wrong. Should have done the dual conversion from the start. Going to read up on that now.
Thanks for the tips on teflon paste, I hope I can get it here.
Still leaking at the master / distributor block connection. Even with another quarter turn it wouldn't seal.
Not sure what I can do now beside buying a third master and another distributor block. Right now I'm so annoyed by the whole issue and the inherent problems of the parts or construction that I might just ignore it for now and let it leak and refill. Then convert to a dual master in winter. The more I worked on this, the more I saw where things can go wrong. Should have done the dual conversion from the start. Going to read up on that now.
Thanks for the tips on teflon paste, I hope I can get it here.
Since 1993.
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- Posts: 737
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- Location: England
Re: Brake bleeding
FWIW I had this problem many years ago. I tried a couple of replacement taper thread fittings I got from U.S. as never seen them here in UK.
In the end I took the M/C and fitting to a brake specialist (an old guy who makes classic car brake lines etc). He scratched his head and said that'll never work so he took it out back and melted some copper on it and machined it down to make a compression type end. He screwed in to the angle I requested and never had any more leaks - maybe 15 years now.
In the end I took the M/C and fitting to a brake specialist (an old guy who makes classic car brake lines etc). He scratched his head and said that'll never work so he took it out back and melted some copper on it and machined it down to make a compression type end. He screwed in to the angle I requested and never had any more leaks - maybe 15 years now.
Dave Langhorne 65SL
UK
UK
Re: Brake bleeding
Tape and sealer are made for pipe threads, like used on the heater hose neck and the vacuum ports.
Brake lines use an SAE 45° flare fitting. The sealing is between the tube flare and the seat. The threads just push the two metal parts together with a large force which is intended to create a metal to metal seal. Pipe threads are fine when you have less than 20 psi pressures like the heater hose and the manifold vacuum, but the pressures in the brake line are much higher. If the metal to metal seal of the brake fitting leaks, then doping up the threads will do absolutely nothing to stop a leak. Worse, the sealants can get into the brake fluid and cause a clog.
Never Never Never Never use a thread sealant on a flare fitting. Just don't. It is an amateur mistake.
Brake lines use an SAE 45° flare fitting. The sealing is between the tube flare and the seat. The threads just push the two metal parts together with a large force which is intended to create a metal to metal seal. Pipe threads are fine when you have less than 20 psi pressures like the heater hose and the manifold vacuum, but the pressures in the brake line are much higher. If the metal to metal seal of the brake fitting leaks, then doping up the threads will do absolutely nothing to stop a leak. Worse, the sealants can get into the brake fluid and cause a clog.
Never Never Never Never use a thread sealant on a flare fitting. Just don't. It is an amateur mistake.
1966 Thunderbird Convertible (Emberglo / White-Emberglo)
Modified 428 - stroked, rollercam, aluminum top end, headers
Livermore, CA
Modified 428 - stroked, rollercam, aluminum top end, headers
Livermore, CA
Re: Brake bleeding
@David: Wish I had someone like that!
@jtschug: The flare nuts seal fine. The problem is the tapered thread of the distributor block that goes into the master. Which doesn't seal when torqued to specs. My theory is that these replacement parts are not exactly like they were back in the day. But yes, getting sealant into the system sounds bad.
@jtschug: The flare nuts seal fine. The problem is the tapered thread of the distributor block that goes into the master. Which doesn't seal when torqued to specs. My theory is that these replacement parts are not exactly like they were back in the day. But yes, getting sealant into the system sounds bad.
Since 1993.
Re: Brake bleeding
Ah. Tapered thread = pipe thread, it does require a sealant. This must be a '64 because I don't think the disc brake system uses any pipe thread in the brake lines.
1966 Thunderbird Convertible (Emberglo / White-Emberglo)
Modified 428 - stroked, rollercam, aluminum top end, headers
Livermore, CA
Modified 428 - stroked, rollercam, aluminum top end, headers
Livermore, CA
Re: Brake bleeding
What about Loctite 542? Looks like this is made for threads on hydraulic tubing.
Since 1993.
Re: Brake bleeding
I recommend that everyone go back and reread this post from the start as items are just going around again, and small things are getting missed.
The brass block is pipe thread, and basically is a one time use per rotational location. Every time you tighten it the block needs to turn a little more, do to its taper to get a seal. Brass on steel Master; brass is soft, it deforms, loss of seal.
Sealant is required on the threads, but it will not make up for the deformation of the brass block due to over tightening. This is why I recommended to get several blocks, and mix and match the orientation to get a correct fit.
Good luck, and keep on trying, you will get there. Do not give up.
The brass block is pipe thread, and basically is a one time use per rotational location. Every time you tighten it the block needs to turn a little more, do to its taper to get a seal. Brass on steel Master; brass is soft, it deforms, loss of seal.
Sealant is required on the threads, but it will not make up for the deformation of the brass block due to over tightening. This is why I recommended to get several blocks, and mix and match the orientation to get a correct fit.
Good luck, and keep on trying, you will get there. Do not give up.
CDN Member since 1975 #2086
Flock: 1964 Landau Original Family Owned
1964 Sr Convertible "RAVEN"
Past: 2003 Blk Lab "RAVEN" "RIP"Nov 15/17
1964 Lincoln vin4Y86N00007
1964 Red Convertible
Flock: 1964 Landau Original Family Owned
1964 Sr Convertible "RAVEN"
Past: 2003 Blk Lab "RAVEN" "RIP"Nov 15/17
1964 Lincoln vin4Y86N00007
1964 Red Convertible
Re: Brake bleeding
Totally agree with Raven on the brass block fitting. Goes the same for copper type washers. Both soft metals. Recently helped a fellow tbirder with a fuel leak on a 1957 bird carb and ended up purchasing a new brass banjo fitting to address it. No overtightening and do your best to make sure your connections are square and well fit before tightening down. The 57 is now a happy puppy with no fuel leaks!
Randy
Randy
Thunderbird Registry #37580
1964 Ford Thunderbird 2DR HT ("Thelma"-our California girl)
1964 Ford Thunderbird 2DR HT ("Thelma"-our California girl)