brake pedal question

[quantumleap]

sometimes lately my brake pedal will depress like theres air in the line but if i let it retract it recharges with pressure. the longer i hold it, the easier it is to push to the floor without braking
...

[BobbyFord]

Sounds like the master is bypassing internally. If you hold it with light pressure will the pedal creep to the floor?

[quantumleap]

after some time it will yes but like i said, if i release it again it regains pressure. also drips down behind the pedals in the cab slightly

[BobbyFord]

It's time for a new master cylinder.

[quantumleap]

thats it? now can i just add a booster and master cylinder at the same time to my stock drum setup?

[fordman]

yes you can. you will need the brackets to mount the booster. or make your own.

[quantumleap]

is that a 67 only part for the bracket and booster?

by the way master cylinder did the job! Thanks bobby

[fordman]

all trucks up to 79 used a bracket to hold the booster to the firewall.

[quantumleap]

so im understanding correctly...all trucks from 67-79 use the same power booster bracket, but 67 has a one year only booster?

[fordman]

65-77 all had a bracket that would work with 65-77 trucks. sometime in mid 77 they booster brackets changed. to a different style. the booster for 67 had a shorter rod so it is a different booster. 65/66 also had a different lenght rod than the other trucks. boosters were mounted directly to the firewall and pedal bracket starting in 1980 trucks. so no need for mounting brackets on the 80 and newer boosters.

[quantumleap]

got it thankyou

[1971 Farmer-250]

I'm having a similar problem with my brake pedal. When I press on the brake pedal for the first time it will almost travel all the way to the floor before braking, I release then it the pedal comes up has more pressure on the second press down and so forth. The same thing happens again after I've been driving for a bit and press down on the brake pedal. How do I know if it's my master cylinder or my booster?

[fordman]

that sounds like a brake fluid problem. and air in the system. i would bleed the brakes again.

[70_F100]

that sounds like a brake fluid problem. and air in the system. i would bleed the brakes again.

Or they might just need to be adjusted...

[1971 Farmer-250]

There was air in the brake lines and the PS caliper was loose. Thanks Guys! Much easier ($$$) fix than an new master or booster.