Hello,

My right rear e-brake doesn't engage (disc brakes). The left side works fine and depressing the brake pedal engages both rear brakes normally.

Here is some background:

The right rear e-brake mechanism was seized in a half-open position. I know this because when I pulled up the e-brake, the mechanism on the caliper would move maybe 1-2mm; not enough to engage the brakes. It was this way for at least one year.

Today, I disassembled that section of the caliper (spring, nut, washer, and lever) and cleaned off all the rust. I also replaced the pads while I was at it. After reassembling, the mechanism moves freely again (in tandem with the e-brake) and opens/closes to its maximum travel.

However, even with the e-brake engaged, I can still spin the wheel freely. It's like the piston isn't actuating with the e-brake mechanism.

Any ideas?

 

After it was seized, maybe the auto-adjust mechanism inside the caliper isn't right??

When you put new pads in, you had to twist the piston to retract it & make room for the new pads. You can give the adjustment mechanism a head-start by not twisting the piston in all the way. Just far enough to get the pads installed & so they're not dragging. Sometimes if you retract them in fully, it takes forever to adjust itself to where it works.

I don't remember the auto-adjustment procedure, but thinking it's something like pulling the handbrake lever many times up & down. Or pull the caliper & spin the piston out a bit.

The real check will come as the pads wear down. The handbrake will either auto-adjust itself or not.

 

Thanks for the reply!

I did actually try pulling up and releasing the e-brake several times but it didn't seem to make a difference. I'll keep trying though.

Two additional observations:

1) This caliper's piston was noticeably more difficult to retract than the other side
2) Sometimes when I pull up the e-brake, I can feel more tension.

Do these help pinpoint the problem some?

 

#1 - The piston being more difficult to spin, makes me suspect some corrosion or other issues with the internal auto-adjust mechanism.

Your original post says it moves freely again. Did you mean the internals or just the action of the external lever?

I haven't actually taken the internal mechanism apart. When I had a similar problem, I got rebuilt calipers. For me, it was dragging brakes causing overheating & corrosion.

 

The external lever moves freely. I can't tell if the internals are corroded or not, but I can move the lever by hand without needing leverage. I didn't check, but I'm pretty sure that the piston doesn't move in tandem with the external lever.

 

Once the auto-adjust mechanism takes up it's slack, the piston should move with the lever. But it's not a huge obvious motion. You might have to hold the caliper in your hand & FEEL the piston moving rather than see it moving.

 

Hmm okay.. I'll keep working it and see if it ever start working again.


Thanks!

 

Sounds like the auto adjust is broken, I would just replace the caliper and be done with it.