abspeedway

Hi I have a 1957 olds supper 88 while driving if I touch brake pedal it sucks down to the floor and all four brakes lock up brakes will not release. I let the car sit for several hours and the pedal will come back up and the brakes release.
Any ideas where to start

Tj Pal

Sounds like weak old brake hoses. When the brakes are released the hoses will collapse, tend to get soft as they age.

oldcutlass

Power brakes? Start with the power booster and M/C

Tedd Thompson

X2 on the collapse line but usually it will only happen on one wheel.... Tedd

abspeedway

I have had the rubber hose collapse on other cars but it was only one wheel. I jacked the car up and all four wheels were locked. The next time it happens should I open brake lines on master cylinder to see if both front or rear wheels release? Car has power brakes

coldwar

Without examination this is a pure guess based on experience: The power booster assembly is assembled incorrectly or a component in the booster has failed. I might try disconnecting and plugging the vacuum supply to the booster, also on the engine side to prevent a vacuum leak when running, and then *CAREFULLY* try the brakes and check results. It takes a few pumps of the pedal to purge the vacuum supply if the vacuum tank and vacuum check valve are in place and functioning but disconnected or if the engine is off or stalled. Brakes on a Treadle-Vac system with no boost assist feel rock hard but should slow the car normally if all is as expected and OK on the hydraulic side of the system. Good luck - Be careful.

abspeedway

I disconnected vacuum from the booster drove car brakes worked did not lock up, the pedal was hard like you said but worked ok.
I reconnected the vacuum and tried to drive car back into garage brakes locked first time I touched brake pedal.. Looks like I need to buy new booster. Thanks for the help

redoldsman

There is not really a separate booster and master cylinder on a treadlevac. It is all pretty much one unit. You will need to have yours rebuilt. I had mine done by Karps in Upland, CA. I have been very pleased. Here is a link.

http://www.karpspb.com/