1978 Ford Thunderbird Low pedal, not air, not Master.

CAPNDENNY1

MEMBER
1978 FORD THUNDERBIRD

Brakes problem
1978 Ford Thunderbird V8 Two Wheel Drive Automatic 170K miles

I have a 1978 T-Bird that has a low pedal and weak brake issue. I replaced the rear brake shoes, it has good pads on the front, and I have replaced the master cylinder, and all 4 of the flexible rubber brake hoses. I bleed the brakes an dstill have too much travel in the pedal. I have adjusted the rear brakes manually to where the brakes are just about to drag, and still too much pedal travel.

I replaced the rear wheel cylinder pistons, but not the cylinders. I haven't touched the fron t brakes, because it appears the pads are new.

Is there any way the proportioning valve could cause this? Like perhaps the front brakes aren't being used at all? That might explain why they look new?

I've had ti to several shops, they say the power booster is bad, but that would give me a stiff pedal. They also want to put new brake line in, but I don't see a leak anywhere?

1 Reply

JACOBANDNICKOLAS

MECHANIC
108,179 POSTS

The rear brakes need to be adjusted until there is a slight drag on them. After the initial adjustment, replace the brake drums, pump the brakes to center the shoes, and readjust one more time. See if that helps. As far as the booster, I agree with you. The steel lines, if not leaking, are not causing the problem. They may be recommending replacement because of rust issues and the potential of them failing.