c5 low brake

[69sniper]

i have a 69 camaro with 98 f-body c5 brakes all around. a 76 corvette non-power master and still use the dist. block that i had on the car with 4 wheel drums. the brakes have been blead and still have a low pedal and wheels will not lock up. any help?

[MrQuick]

I believe your combo valve may be a problem. But how much free play do you have between the pedal rod and master cup?

[69sniper]

there is no free play. the pedal will goto the floor when pushed and will build up if pushed a few times.

[tumper93]

Your master cylinder is bypassing causing the pedal to fall yet be "pumped" a few times to get pressure. Just replace the master cylinder! However, the vette master cylinder is 1 1/8 bore and is too large for adequit pressure for the c5 calipers. A 7/8 master cylinder is the correct bore size for correct pressure and volume to operate. For my c5 setup I used a c5 master cylinder for mine and it works great.

[69sniper]

my master cylinder is a 1 inch. did you use the c5 master and booster? i first tried the 1 1/8 inch and it is doing pretty much the same thing. also how did you hook up the e brake cable?

[dipren443]

Even if this is a problem with the master cylinder, I would still swap out that combo valve for a disc/disc one ASAP.