Brakes are locked up

[dcullen]

Hello,
I am fairly new to subarus but not to the car game. I am chasing down a brake problem on my girlfriend's 1993 Legacy FWD. The other day her brakes "locked" on at a stop sign and wouldn't budge. We ended up realizing that the right rear corner (Passenger side rear) was not moving freely so i popped off the wheel, pulled off the caliper, stuffed the brake pads in the caliper so the piston wouldn't come out and bungee corded the caliper out of the way and drove home. The brakes still seemed to be dragging a bit but i just figured it was the other rear caliper freezing up as well (because in my experience they tend to fail around the same time in pairs, front/ rear). So i replaced both rear calipers, bled the brakes and took the car out for a ride and same thing happened again. They weren't locked up enough this time to not be able to move the car so i managed to get it back in the drive way for the night.

I jacked up the rear and front and it is the right rear and front left brakes that are frozen on. So this makes me think it is the master cylinder? It is dark out right now so i haven't done any more investigating on the car, just about 3 hours of subaru forum searching here and nasioc with no luck.

My VW has the brakes split in the same manner on the master cylinder, diagonally, which makes me think they might be the same on her car. Please correct me if i am wrong, I will know tomorrow morning when i start investigating more.

Has anyone had this problem before? Is there a proportioning/ bias valve somewhere that could be clogged in some way to lock those two brakes up?

Thank you in advance for any help,
Dan

[Legacy777]

You sure the problem isn't the parking brake? The rear has an integrated drum parking brake.

Also, is your GF's Legacy MT or AT? The MT cars have a hill holder tied to the master cylinder that may give you some issues.

[dcullen]

You sure the problem isn't the parking brake? The rear has an integrated drum parking brake.

Also, is your GF's Legacy MT or AT? The MT cars have a hill holder tied to the master cylinder that may give you some issues.

Yes I am sure it it not the parking brake because the front left is locked up as well. It is a manual transmission so I will check into the hill holder. Can you explain any more about it? Which wheels it effects and how I could go about disabling it to see if it that helps anything.

Thank you,
Dan

[tahiti350]

Hill holder is a cable operated valve located under the master cylinder on the frame rail. THe other end of the cable attaches to the clutch mechinism so that when you depress the clutch to the floor with the brakes applied it locks pressure in the brakes to keep from rolling when starting out. I don't know if it affects all brakes or just a pair, but you should be able trace the plumbing (can be a pain if you have ABS though).

If the cable is binding it could be keeping the hill holder applied. Try disconnecting the cable from the hill holder and make sure it releases (IIRC it is spring loaded to release).

May not help, but it's a starting point.

[Legacy777]

Yeah, I'd remove the cable and see how things work. It's setup to work only on one brake circuit. So it would affect LF & RR or RF & LR.

[dcullen]

All fixed.

Turns out the return spring had rusted out and the cable was not returning. I removed the cable entirely and now the brakes are all set!

Thank you all very much for the help.

-Dan

[evolutionmovement]

I think that might be a relatively common issue as I've seen a lot of the old hill-holder cars with the cable removed. Always wondered why.