Rear Caliper Help!

[ESProtege02]

I read up on the rear caliper before tackling the job. So I took off the 14mm bolt that's just a cap for that hex screw adjuster for the piston. Well I got the hex screw to come loose and it unscrewed maybe a half turn and that's it. But now I can just move the screw back and forth, it won't tighten and stay tight and the piston doesn't move at all. Could my piston be siezed up and I need a new caliper? The brakes were pretty much metal to metal. I don't know how long they were like this. The car sat for probably a good 2-3 months(from probably January until April) only being driven a few times during that time. Any ideas on what to do? Am I doing something wrong?

 

[rs39]

So a half turn was all the way out to stop, then it can go 'many turns' back to tight? Sounds more like the adj to tighten was not happening, esp if they were never re-set after the last brake job.

Tried a c-clamp to compress the system yet?

 

[ESProtege02]

I haven't tried compressing the system. I'm afraid to do anything more until I know for sure whats going on. I don't want to start cranking on stuff and break it if it's not already broken. I unscrewed the adj screw and it came loose and turns maybe 1/2-1 full turn but then acts like it's just stuck. Turn it back to tighten it and it's just really lose in there won't stay tightened. It's pretty much free-moving for about a 1/2 turn between clockwise/counterclockwise movement. The pistion doesn't move at all. Not sure if I need to crank on the adj screw and try to loosen it more or it something is messed up.

 

[jbc]

ES Rear caliper

Do not use a C clamp. The 4mm hex screw (inside the 14mm bolt hole) turns a gear that retracts or tightens the caliper piston. It can be pulled out without needing to turn if its clean. It sounds like you have a corroded screw / passage.

I used rust penetrant and then a tap to get a hold of the screw adjuster pulled out and then plenty of wd40 to flush out the housing and used new from the dealer screw adjusters. They cost ~ $3.00 ea

 

[ESProtege02]

I'll have to give that a try. I'll soak it with penetrant and see if that will work. If not, I'm guessing I'll have to replace the caliper.

 

[lilpoindexter]

My '95 miata uses the same style rear calipers...i never use the car, and one adjustment bolt seized up...so i have to replace a caliper....its expensive man....mazdas are cool, except for the design of these rear calipers, and those stupid sway bar links.

 

[ESProtege02]

That's what I was afraid of. I soaked it with penetrant and let it sit overnight and all I can manage is that 1/2 turn. It just won't move anymore. I haven't even attempted the drivers side yet but I assume it's the same issue. I should probably just replace them both while I'm at it anyway so... there goes more money.