Looks like I may have a rear disc problem.

[Autometer]

On my '78 Malibu, I looked at my rear brakes recently and noticed it looks like they're not being used much.





It's a 9" out of a '77 continental. Since I have 12" rotors up front I had the caprice wagon master cylinder. I didn't have much of a pedal till I swap in a Caddy Saville (4 wheel disc) master cylinder. The pedal is a lot better but I just noticed my rotors. I'm still using the stock valve.

Any ideas?

[MrQuick]

do the pistons work and adjust with the parking brake? Maybe they aren't adjusted properly? hey no drilled rotors? jk

[David Pozzi]

some of those Ford rear brakes use huge bore calipers, some are 3"!
I'd verify rear bore size, and install an adjustable prop valve for the rear brakes.

[Autometer]

do the pistons work and adjust with the parking brake? Maybe they aren't adjusted properly? hey no drilled rotors? jk

Actually they are not hooked up.

I never got around to adapting ford to Chevy on my e-brake cables. Could I just put a spring on the lever to put some load on it?

[Autometer]

some of those Ford rear brakes use huge bore calipers, some are 3"!
I'd verify rear bore size, and install an adjustable prop valve for the rear brakes.

Thanks, I'll check into that.

[LTorres]

Installing an adjustable valve like the one available by Wilwood through Precision Brakes Company at 1 866 992 7253 would be great!! It's only $39.99 with the fittings.

[fuzzyonion]

Proportioning valve=less pressure to rear brakes.

Actually, I'm sure with those honkin' calipers you do need to reduce pressure, but you need to find out why they aren't working, and giving them even less pressure doesn't sound like the answer... or am I confused?
You also dont want to run your stock valve and an adjustable valve at the same time.

It could be that there's just so much iron around them that they are absorbing alot of heat, so dont appear to be working much, though by all rights, as big as the calipers are, they should be locking up on you.

[LTorres]

The idea would not be to decrease with an adj. valve but to increase. Also another possability here may simply be a master cylinder change.(MOre Volume.) PressurexArea=Force but more area, also would decrease travel. There is a good chance that the pads are never engaging the rotor!! A master cyl change could provide more volume, however I agree that a decision should be made to run either the adj. valve or the original but not the two valves together...

[fuzzyonion]

So you're saying to remove the stock valve and set the pressure reducer to not reduce much? That makes sense, because you cant get more than the master cylinder will give. However, if he needed more fluid volume, wouldn't the pedal be low?

I dunno. I thought he said the pedal felt fine. We'll see when those rear brakes work. Good luck.

[LTorres]

Hence the reason for a possible Master cylinder change.

[LTorres]

Good luck man....