Brake piston Allen bolt stripped, What to do now? Help!

My rear brake piston wont retracct and i cant get the bolt out from the brake. Is there any other option other than new caliper? thanks.
 
pretty sure you can still retract the piston. you drill into the bolt and then unscrew it out that way. therefore all that will need to be replaced is the bolt. its not going to screw up the caliper itself. just the bolt. either that or you should take it in. drilling woult be cheaper tho. just go get the bolt from mazda
 
If you can't drill it with the caliper still on the car (that does seem pretty hard), then just remove the rest of the bolts that are holding it to the car. IIRC you need to remove the two 14mm bolts holding the caliper bracket, the 14mm bolt holding the parking brake cable bracket in place, and the 12mm banjo bolt holding the brake line.

From there you can remove the whole caliper assembly with the rotor. Then you can work on getting that bolt loose/drilled on a bench.

Out of curiosity, have you tried soaking the bolt in penetrating oil for a couple hours? And have to tried attaching a short breaker bar to the bolt and beating it with a hammer? On my car the bolt you're talking about is the only one that came loose easily on my rusted-out, jammed caliper.
 
I've had this same problem on both rear calipers before, what has actually happened is that bolt has been completely corroded, in my case I had to completely replace both calipers. There is no replacement bolt that I know of, you may be able to find one at a generic hardware store though.
 
if the bolt is frozen, chances are the piston is also frozen, and you will need a new caliper.

fyi: that allen "bolt" is not a bolt. its a gear spline that connects between the parking brake and the piston gear. there will bo no off-the-shelf part from any hardware store.

sounds to me like the perfect opportunity to upgrade to MSP rear calipers! :D
 
Try using a easy-out (reverse-threaded drill bit) with PB BLaster.

If it still doesn't back off - THEN go buy a new caliper. :(
 
Both of mine were seized too. I ended up having to buy new rear calipers from Autozone/Napa for $150 each. A friend said if you open the brake bleeder it will take pressure off the allen bolt and you would be able to back it out of the caliper. But he told me after the fact I already had the new caliper on. But it's worth a shot.
 
My rear has the same issue. It works fine, but you cannot retract the piston to remove the pads. I was able to replace the rotors while they were stuck, just re-used the rear pads. My car has like 98K on it with TONS of meat on the rears.

I did use the stripped bolt as an excuse to order a MSP calipers all around...1 more week and they will take the place of all my calipers..
 
Is there any way to retract the piston like the MSP brakes by rotating the piston out?

On the rear ones, you can rotate the piston to bring it in (looking at the piston I *think* you'd go clockwise) but you'll probably tear that rubber boot and most certainly damage the piston seal. The good news is that you should be replacing those parts so rotate away!
 
Mine doesn't have a bit of rust on the calipers, either a past mechanic killed it or I just stripped it without even noticing.
 
these cars dont rust

Thank you for making me laugh this morning...

I'd give your car one Quebec winter and it would start rusting out. As MazdaSpeeder said, not everyone has a garage, almost every protege(5) I see has at least some rust around the wheel wells or around the badge, Mazda just did a s*** job of protecting the metal. Regardless of the brand of car, I don't think there's a such thing as a non-rusty undercarriage up here, our climate kills cars.
 
I had the allen gear get stuck on my right rear caliper. It ended up stripping the part where the allen wrench fits in. If you put an allen wrench in at the correct angle, you can pull that gear out. I did that, sprayed some WD40 in there, pulled the gear from the other caliper that wasn't stripped and used it's gear to retract the piston. Then just put the stripped one back in it's place after I adjusted the caliper and put the good gear back in the other caliper.

Hope that helps/makes sense.
 
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