1968 brake problem

[cool68]

hi guys need some help.... i have a 1968 gt/cs with power brakes i just installed a new booster (midland) the problem is i can,t get the rear brakes to bleed ....the fronts bleed fine....i also notice in the front bowl on the master cylinder when the brake pedal is pressed..fluid squirts out...please help

 

[Ruppstang]

Did you rebuild your proportion valve? Did the car sit for a long time or was the system left open? You could have rust blockage. We need to know more and what you have done.

 

[cool68]

Thank you

The car sat for along time the system was closed I did notice the the old master cylinder was dry it had no brake fluid.

 

[dalorzo_f]

"fluid squirts out". Where? Not normal under operation... if you mean with the lid off, bound to happen, need to cap it before bleeding.

Probably shot seals in the master cylinder.

The rears should gravity bleed if they do not, possibly blocked lines...

 

[franklinair]

I'd start at the beginning and work my way back:
Loosen the fitting @ the MC (front reservoir) and see if fluid exits the MC. If OK;
Loosen the fitting @ the Shuttle valve (for the Brake Warning Light) to see if fluid passes through it. If OK;
Loosen the fitting @ the Proportioning Valve to see if fluid passes through it. If OK;
Loosen the fitting going into the rear junction fitting (on axle housing) to see if fluid passes through the rigid brake line. If OK;
The only remaining components are the 2 lines for the rear wheel cylinders,and the wheel cylinders themselves.
In this process of elimination, where ever fluid doesn't flow through- the problem is forward.
If the car has set for a long time the old brake fluid may well have turned into sludge, clogging the system.
Marty's & Richard's suggestions are both likely culprits.
Hope this helps.

Neil

 

[cool68]

Thank you

Hey guys thanks for all the help My master cylinder is new to let me see if I got this right if its squirting out of the front bowl with the cap off I have a bad master cylinder ? Also who rebuilds the Dist blocks and proportioning valves?

 

[franklinair]

The MC is probably OK. The fluid you see 'squirting' is due to the fluid displacement caused by the piston movement within the MC. (Master Cylinder failure is usually internal, allowing fluid to leak out the rear seal into the PB Booster- which in turn ruins the Booster diaphragm)
Secure the MC cover and proceed to locate the blockage in the brake fluid circuit.

Neil

 

[cool68]

Thank you

Ok thanks I just ordered a proportioning valve / Dist block now I just need to get the lines off the old one

 

[Ruppstang]

Take great care removing the old lines. Often the nut is rusted to the line and you will twist off the lines. Then you will be ordering a line set which actually is not a bad idea.
If you have no use for your old distribution block and proportion valve I would give you $20 for them provided none of the threads are stripped.

 

[cool68]

Take great care removing the old lines. Often the nut is rusted to the line and you will twist off the lines. Then you will be ordering a line set which actually is not a bad idea.
If you have no use for your old distribution block and proportion valve I would give you $20 for them provided none of the threads are stripped.

It's worth a bit more then $20.00

 

[Ruppstang]

PM me if you want to sell it and what you need for it.

 

[franklinair]

Give all the fittings a good dose of penetrating fluid, let them sit for 24 hours before attempting to loosen. As Marty said, the fittings/lines may be corroded together. (It's called intergranular corrosion caused by dissimilar metals continually in contact.)

Neil

 

[dalorzo_f]

About $150-200 is what nice OEM ones seem to be going for these days....:wink: the newish repros look quite nice, but almost as much, IIRC around $125.

 

[cool68]

Give all the fittings a good dose of penetrating fluid, let them sit for 24 hours before attempting to loosen. As Marty said, the fittings/lines may be corroded together. (It's called intergranular corrosion caused by dissimilar metals continually in contact.)

Neil

Update I got all the lines off the proportioning valve Dist block. And I didn't break one line I'm so happy

 

[cool68]

PM me if you want to sell it and what you need for it.

Did you get my pm?

 

[cool68]

Udate udate udate

Just found out what my real problem was. It was a bad rear brake hose I'm still glad I replaced the proportioning valve/ Dist block