[DeTomaso] Brake problem

[SOBill at aol.com]

Will,
 
When you hit the brakes, you open a valve in the booster which  applies 
atmospheric pressure to one side of the diaphragm. The Other side of the  diaphragm 
has engine vacuum and the pressure difference moves the brake  actuation rod 
into the master cylinder. The pressure difference on the booster  diaphragm 
times the diaphragm area is added to the pressure of your foot to  apply 
pressure to the master cylinder.
 
When you are not using the brakes, there must be a small gap  between the 
pedal rod, the actuation valve, and the position where  the actuation valve 
opens. This gap is to allow for thermal expansion,  vibration, et al. If your unit 
has never been apart and you haven't done  anything with you brake pedal, and 
the brake pedal freely, fully retracts when  not in use, you could have a 
sticking actuation valve in the booster. A sticking  actuation valve in the 
booster will apply the brakes for  sure.
 
Booster innards are not rocket science. The booster be  disassembled, cleaned 
and repaired. You, or any good auto brake shop guy with  gray hair can do it. 
The internal parts are also quite standard.
 
Have fun,
 
SOBill  Taylor
sobill at aol.com



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