Help. can not figure out why my brake pedal has little travel and hard to push.1972 SS BB with vacuum pump from MP Brakes new booster & master cylinder. OE power disc/drum set up. If any one has corrected this problem please help!!
Gary.

Originally posted by gnunzio:
Help. can not figure out why my brake pedal has little travel and hard to push.1972 SS BB with vacuum pump from MP Brakes new booster & master cylinder. OE power disc/drum set up. If any one has corrected this problem please help!!
Gary. are you sure that when you hooked new booster rod up to pedal you put it in the right hole. there is some geometery that is involved. i have manual brakes and i had the m/c rod in the wrong hole same deal real had pedal i moved the rod to the other hole and this gave me more leverage on the pedal and works like a charm. better feeling brakes than my camaro with power assist. tommy

Tommy, thanks for the reply yes my booster rod is in the lower hole. I have ordered another booster from Steve gregorie, sending OPGI'S back for refund hope this fixes the problem. Do not know what else to do????? Any one?

Sounds like the booster is in question. Check to see if it holds vaccum by shutting the car off then pulling the checkvalve and line off the booster.You should hear a noticeable whoosh from the booster.It should hold enough vaccum for at least 30sec. If not you have a ruptured diaphram or faulty check valve.

Nunz,
Try this,warm the car up a little so its off the choke and starts easily.Shut the motor off and pump the brakes so you use all the vacumm thats stored in the booster.About 4 to 6 pumps should do it.Brake pedal should be hard and high if the rear shoes are adjusted properly.Now hold the brake pedal down as you start the car,as soon as the motor starts the pedal should drop with the added vacumm assist.This is how you check a stock booster.
If it doesn't drop when the motor starts you have a bad booster or a low vacumm supply from the motor.
You said the car had OE disc/drum setup,how was the pedal before the upgrade?
Does the MP vacumm pump suppliment the engine vacumm supply or replace it?

I had the same problem turned out to be a faulty booster and the company sent me a new one

M P brakes vacuum pump replaces engine vacuum as vacuum supply. Pump up for grabs! problem was faulty O P G brake booster. Just replaced OPG unit with Steve Gregori's booster all OK Pedal could feel better but I think Raybestos Super Stops may have something to do with it. Thanks for your replys! any one run the super stops??

Wow, it replaces the vacumm supply from the motor,that must be some pump.
All the late model cars with vacumm pumps just suppliment the vacumm supply.

350SS Ya it is a great pump comes on at 17 in HG shuts off at 21 in hg. Any one need one? selling cheap!
Gary GNUNZIO1@AOL.COM

Try the upper hole on the brake pedal (quickest way) or get a smaller diameter (like 1") master cylinder (probably, best way). I think that MP Brakes uses 1 1/8" masters.

Either way will increase travel and brake pressure. This is assuming that your booster is working properly.

Theo.