'72 disk brakes help
 

I have recently purchased a '72 c20 with 4 wheel disk. The truck stops but not quick and with alot of effort on the pedal. I am looking at possible bad master cylinder but this is only a guess. Pads are in good condition, rotors are clean and it doesn't pull when braking. Fluid change might help but that can't be causing the issue.
Any advice on this?

Thanks,

Re: '72 disk brakes help
 

what kind of disc brake calipers are on the rar of the truck?

Re: '72 disk brakes help
 

I believe the booster runs off a vaccum. Make sure that line is secure to the back of the carb..mine had a small leak...simply put-leak=no brakes.

Re: '72 disk brakes help
 

Thanks Cool72, my vaccum line were pretty bad so I checked and was only getting -4 pressure. replaced the lines and am around -10 to -14 now. Havent check to see if that did it yet. Since the wheels are off I decided to play with the suspension a bit... who knows what I'll find.

Re: '72 disk brakes help
 

Vacuum boosters require about 16-17" minimum to be completely effective. That low vac. you indicated would definitely contribute to lower pressure being applied.