67 roadster brake problem

[jkern]

Spongy brakes. Have to pump up brakes in the morning but they work fine until I park it at night. Next morning pedal goes down almost to the floor. Pump them up, no problem for the rest of the day. Replaced master cylinder. There are no leaks. Pads and rotors appear to be OK. Have bled the brakes several times. Get a little air out of the right rear caliper. Do I need to rebuild or replace the calipers or could it be another problem? Any suggestions? John​

 

[JohnZ]

Have you bled BOTH the inboard AND outboard rear caliper halves? There are two bleeders on the rear calipers, and the inboard one should be bled first. You may have a bad piston seal on that rear caliper, allowing air entry into the caliper bore.

 

[jkern]

Have you bled BOTH the inboard AND outboard rear caliper halves? There are two bleeders on the rear calipers, and the inboard one should be bled first. You may have a bad piston seal on that rear caliper, allowing air entry into the caliper bore.

Thanks for the input. Never noticed the inboard bleeder. Will try it this weekend. JK