setting pedal height on booster brakes??

[Ed ke6bnl]

Well I purchased a new booster and M/C for my below floor 50 F1 pu.  By the time I got a chance to get to the motor and rest of the drive train in I found the vacuum booster  to be defective. It was in the truck over a year b4 being test.  I got it rebuilt to eliminate having to modify the setup.  It works, but there is about 4to 5in play in the pedal b4 it starts to feel pressure on the pedal for stopping purposes.  Can I put a stop under the car so they pedal will only have about 1-2in of play b4 it starts the activation of the brakes???
Do I have to have a spring to put extra force to keep the pedal up and returned even though it seems to return on its own.  to be honest I do not understand how the booster works and not sure if I comprimise how the vacuum booster functions  if the pedal doesn't return all the way up will continue to bleed off.  Thank for your help on this poorly worded question. Ed ke6bnl

[Pope Downunder]

Well I purchased a new booster and M/C for my below floor 50 F1 pu.  By the time I got a chance to get to the motor and rest of the drive train in I found the vacuum booster  to be defective. It was in the truck over a year b4 being test.  I got it rebuilt to eliminate having to modify the setup.  It works, but there is about 4to 5in play in the pedal b4 it starts to feel pressure on the pedal for stopping purposes.  Can I put a stop under the car so they pedal will only have about 1-2in of play b4 it starts the activation of the brakes???
Do I have to have a spring to put extra force to keep the pedal up and returned even though it seems to return on its own.  to be honest I do not understand how the booster works and not sure if I comprimise how the vacuum booster functions  if the pedal doesn't return all the way up will continue to bleed off.  Thank for your help on this poorly worded question. Ed ke6bnl

What leverage are you running on your pedal?  The more leverage, the more travel.
As far as free-travel, I cannot undersatnd how you can get that much, unless something is disconnected or mismatched.  The connection from the booster push-rod to the master cylinder should be all mechanical with just a bit of free-play; if not, something is mis-matched.  For example, if the push-rod is short for the master cylinder, there will be free travel in there; this is simple enough to measure, if you remove the cylinder.  Another source could be the wrong thickness discs for the calipers, or very badly adjusted drum brakes.

I would always run a return spring, even if the weight of the pedal is not causing a light drag on the brakes.

[enjenjo]

I think the pushrod between the booster and master cylinder may be too short. That would give the symtoms you have.

[Ed ke6bnl]

I think the pushrod between the booster and master cylinder may be too short. That would give the symtoms you have.

It seemed like the rod from the booster to the M/C may have had an adjuster on it a threaded rod. I will play around with it tomorrow and see if I see anything unusual.  Ed

[Inprimer]

Well I purchased a new booster and M/C for my below floor 50 F1 pu.  By the time I got a chance to get to the motor and rest of the drive train in I found the vacuum booster  to be defective. It was in the truck over a year b4 being test.  I got it rebuilt to eliminate having to modify the setup.  It works, but there is about 4to 5in play in the pedal b4 it starts to feel pressure on the pedal for stopping purposes.  Can I put a stop under the car so they pedal will only have about 1-2in of play b4 it starts the activation of the brakes???
Do I have to have a spring to put extra force to keep the pedal up and returned even though it seems to return on its own.  to be honest I do not understand how the booster works and not sure if I comprimise how the vacuum booster functions  if the pedal doesn't return all the way up will continue to bleed off.  Thank for your help on this poorly worded question. Ed ke6bnl

[Inprimer]

Well I purchased a new booster and M/C for my below floor 50 F1 pu.  By the time I got a chance to get to the motor and rest of the drive train in I found the vacuum booster  to be defective. It was in the truck over a year b4 being test.  I got it rebuilt to eliminate having to modify the setup.  It works, but there is about 4to 5in play in the pedal b4 it starts to feel pressure on the pedal for stopping purposes.  Can I put a stop under the car so they pedal will only have about 1-2in of play b4 it starts the activation of the brakes???
Do I have to have a spring to put extra force to keep the pedal up and returned even though it seems to return on its own.  to be honest I do not understand how the booster works and not sure if I comprimise how the vacuum booster functions  if the pedal doesn't return all the way up will continue to bleed off.  Thank for your help on this poorly worded question. Ed ke6bnl

Sorry will try again  WWW.hotrodheaven.com/tech/brakes/brakes1_index.htm

[Ed ke6bnl]

Well I purchased a new booster and M/C for my below floor 50 F1 pu.  By the time I got a chance to get to the motor and rest of the drive train in I found the vacuum booster  to be defective. It was in the truck over a year b4 being test.  I got it rebuilt to eliminate having to modify the setup.  It works, but there is about 4to 5in play in the pedal b4 it starts to feel pressure on the pedal for stopping purposes.  Can I put a stop under the car so they pedal will only have about 1-2in of play b4 it starts the activation of the brakes???
Do I have to have a spring to put extra force to keep the pedal up and returned even though it seems to return on its own.  to be honest I do not understand how the booster works and not sure if I comprimise how the vacuum booster functions  if the pedal doesn't return all the way up will continue to bleed off.  Thank for your help on this poorly worded question. Ed ke6bnl

Sorry will try again  WWW.hotrodheaven.com/tech/brakes/brakes1_index.htm

Thanks for the site I did put in the 11" rotors as stated

A good example of upgrading would be if you have a Mustang/Pinto 9" rotor and upgrade to a 11" rotor.  Not only does it allow more surface for cooling, it give a significant mechanical advantage.  This results in less pressure and brake force by the caliper to stop your vehicle

Well I took the truck today to a car show at Knotts Berry Farm(So. Calif) and did a lot of adjusting the day b4 and the brakes work great, I do need to take up some of the play in the stop that I had welded on to the pedal arm under the cab and I will be like a new truck I was even able to stop the truck while my boy was driving just leaning over with my hand so I am pleased how it works.  Thanks for the above website and all the usefull information to get me on the right track. Ed