Brakes seized

[Bob Gaines]

Thanks Rodney, I really couldn't tell...if I had to guess, all wheels were affected. I was coming down my home street and into my driveway so it was a short amount of time, not at speed to feel any type of pull one way or another. This is a dual chamber and as soon as I cracked one of the lines coming off the MC and a little fluid came out, I tightened it and all was back to normal.Peddle action etc  I will test the fluid for accuracy though. Thanks for your help!

Scott

I thought you should know that if a original 65 disc brake master it will not have a flare fitting and instead there is a brass pipe to flare adapter the the brake line threads into. The replacements sold have a flare made into them so the adapter is not needed. However it is expected to be seen from a historical standpoint. On your tribute car it made be an issue or maybe not but wanted to let you know.On your car the later model duel master conversion would not be a issue from a historical standpoint given the 4 wheel disc brakes but it would be way safer.

[Royce Peterson]

If you cracked one line at the master cylinder it would affect only one set of brakes. Either the front or the rear.

[SCOTTGTK]

Thanks Bob, it just happened again... seems like it's after a certain amount of use that it seizes up, cracked the front of the 2 lines and now back to quote unquote normal.
But, Royce makes a good point... i thought crack one line, you have essentially cracked both...I'll crack the 2nd line for good measure. At this point though, my confidence level in the current set up is low. I saw a dual cylinder with proportioning valve for front and rear disc at CJ Pony...

[67350#1242]

Dual master cylinders for disc/drum brakes may have a residual check valve in the drum circuit.  Probably not your problem, but if a disc/drum master was used in a dual disc setup, it could possibly mimic the problem you describe.
Have you determined if it is the front or the rear calipers locking up?

[SCOTTGTK]

Thanks 67350#1242, undetermined at this point. Previous owner had zero issues with the brakes and had car for a year... I aquired it and felt like the brakes should be working more efficiently, they were working, I just thought could be better. Is there a way to visually determine if a disc/drum MC was used in error?

[KR Convertible]

Disc/drum should have a smaller reservoir for the drum brakes, usually the front reservoir.

[SCOTTGTK]

Thanks KR, on a disc/disc are the reservoirs same size? I've been shopping them and haven't come across a same size, dual reservoir?

[SCOTTGTK]

Correction... I have seen a couple MC that are same size reservoirs... problem has been, they are described as appliacble for disc/drum set up.
I do see one that is disc/disc, dual reservoir for my car and has proportioning adjuster... the reservoirs are different sizes from Leeds brakes.

[Bob Gaines]

Correction... I have seen a couple MC that are same size reservoirs... problem has been, they are described as appliacble for disc/drum set up.
I do see one that is disc/disc, dual reservoir for my car and has proportioning adjuster... the reservoirs are different sizes from Leeds brakes.

Call Cobra Automotive they sell duel masters designed to be used with rear disc conversions on vintage Mustangs . https://www.cobraautomotive.com/

[SCOTTGTK]

Thanks Bob... that looks like just what I want, complete with proportioning adjuster that can be used.

[67350#1242]

If necessary, one could check the MC for residual check valve by removing the suspected line and probing the hole on the tube seat.  If you feel something rubbery/springy in there it probably is a check valve. No check valve and probe will just pass through (at least 1/4- 1/2").  I believe most mustang setups have the drum circuit on the front hole (please correct me if you know otherwise), so I would check that one first.

[SCOTTGTK]

Thanks 67350#1242.... I'll see what I can find... I'm inclined to replace from Cobra automotive very shortly!