Bleach

What is it with the right rear brake caliper on the 1982-83? I'm on my 3rd caliper since I've had this car... (9 years, 100K miles) the other three calipers are original.

anyway, so a year ago the right rear corner of the parking brake cable got sticky and the parking brake was dragging on that side. My quick fix was to just disconnect that side of the cable so I could drive normal. Now I get around to replacing the cable.
Both sides are working good as far as the cable goes. The left side pulls a little and grabs the rotor hard. The right side pulls the lever all the way back and just barely grabs the rotor at all. (I can still turn it by hand) I can see that in the open position there is a tiny gap between the rotor and pad. (no gap on the left side) When the parking brake lever is pulled the pads do move. The caliper is supposed to turn the piston and stay in contact with the rotor.. right?
why would it not stay close and self-adjust?

I bled and re-bled so I know there is no air in the system. (if that even makes a difference) The brakes work good but there is a little added pedal travel at the top compared to what it should be.

NismoPick

Time to upgrade to 240sx rear calipers!

Bleach

do 240SX calipers bolt right on, fit the rotor perfectly, and use the factory 280zx parking brake cable?

NismoPick

I did a quick search on hybridz.... here's one w/ some good info:

http://forums.hybridz.org/showthread.php?t=96460&

SHADY280

jeeze, i searched for rear brake stuff and came up empty, i asked but people told me to search, i must type the wrong stuff.

SpeciallySpiked

The front ones are self adjusting but the rear ones are not. You can adjust the rear calipers by taking a pair of needle nosed plyers and rotate the cylinder that pushes the brake pad. Tighter = in more, Looser = out more. I had to do it after I got new brakes so they wouldn't be rubbing the whole time. Hopefully that helps ya out.

NismoPick

The rear SHOULD be self adjusting... that's why you have to screw them back in when you put on new pads, because they slowly turn out as the pads wear. And when you bleed the rear brakes, the caliper should become tight, without the need of "manual adjustment."

SpeciallySpiked

ooohhhh, haha as I was writing this I started to wonder if my new pads were just bigger than the other ones. Makes sense and that's a pretty smart design.

Bleach

I DID IT! I can finally fix something on my Z all by myself!

ok, so I pulled the pads out.. well, I tried to. The inside pad was glued solid to the piston. I put so much anti-squeal compound in there and the fact that the parking brake lever was never hooked up on that side so it didnt' move much... caused the stuff to glue the pad there. That must have done something to not allow the piston to adjust. anyway, I cleaned up the pads and brought the piston out just a little. Put it all back in, pulled the parking brake a couple times and BAM, its all good.
Super tight brakes like they should be and it added another 3hp at the wheels.

NismoPick

Wahoo!!!!

jfairladyz

The piston probably wasn't able to turn cause it was seized to the pad No turny = no adjusty.

NismoPick

FYI... don't ever fill the piston seal w/ RTV trying to fill a rip in the seal.... That will freeze up the piston as well. I did that once... WOOPS!

Bleach

ya, if your caliper seals are bad I say just swap in some 240SX calipers. That's a good fix for anything!

SHADY280

the pad glued to the piston doesnt matter. it has those notches in it and the "threads" are behind it the piston top stays the same. glued to the seal maybee, but it shouldnt really matter.

jfairladyz

The piston rotates on a spiraled shaft to adjust itself. If it cant rotate then it cant adjust itself. This only applies to the rears though because of the parking brake. On the front it wouldn't matter.

iestyn.lewis

Just wanted to chime in and say I had the same problem after installing new rear pads - no E-brake, and pedal went almost to the floor before grabbing. When I retracted the pistons by rotating them clockwise, I went pretty much all the way, and may have locked them up. I took the pads out again, then rotated them counterclockwise until I could just barely get the caliper back on over the pads and shims. Fixed the problem completely.

I don't know if this means my auto-adjust is frozen up, or just old, but if someone else comes across this thread by searching, try rotating your pistons counterclockwise until they just barely go on over the pads and shims. I don't know yet whether I will have to readjust them as the pads wear, or if I loosened the mechanism up again by rotating them back from their fully retracted position.