Trouble shoot

[ho428]

I have a 68 Firebird with OEM 4 piston fixed caliper fronts, had drum rears running a C2-3 vette 1" bore manual MC with adjustable prop valve.
I changed the rears to single piston floating disc kit from The Right Stuff, bled the system good.
The pedal goes all the way down now, one pump and it's back up.
I called and they said they thought I needed a 1" bore MC, that maybe I had a bigger one and not getting enough pressure.
My first thought is I don't have enough fluid volume, hence the one pump, which would suggest needing a 1 1/8 or larger bore.

Opinions-Suggestions?

[Apogee]

Gordon, the pedal hitting the floor is usually an indication of not enough volume (too small of a bore) or air in the system. Does the pedal feel spongy or is it firm after you pump it up? What calipers are you running in the rear? I know you said single piston, however those kits based on or around the small metric GM calipers can be set up with either front calipers or rear (Caddy) calipers with integral parking brakes if I'm not mistaken. If the parking brake is not adjusted properly during installation, you can see the same sort of issues that you're experiencing since the pads are "adjusted" for wear by the parking brake actuation and mechanism.

Tobin
KORE3

[ho428]

They are the Caddy type with parking brake, I had a feeling that might cause a problem so I'm calling them to see about a caliper upgrade.