I'm in the process of replacing my brake rotors. When I disassembled the front drivers side caliper I noticed that the piston bolt in the caliper bracket rusted and sized. No way I can get it out. Attached is a illustration. Bolt "C" sized in the bracket "item 8" Can I put it back together and continue driving with this? Any help appreciated.

 

That's the slider ....caliper won't work with that seized. Should be able to clean with emery or steel wool, lube with high temp silicone grease and it should work.

If it's sliding....OK and the retaining bolt is just stuck...put some penetrating oil on it and leave it for a few days. you can change the pads with removing only one bolt

 

Thats the problem I can see its rusted together inside and it wont slide. How come it was working up until now?

 

Probably wasn't
Check your bearings and the rotor wear..the pads were probably dragging for a while. If the rotors are blue you may have cooked the grease in the front hub

 

I don't think so, everything looks normal, identical to the other side. But ok I got to fix it anyhow, thanks for the replies.

 

Just went through the same issue on my 03 build with 85K on the clock - https://www.rx8club.com/showthread.p...ghlight=piston.

 

yep it HAS to work--check the rubber on the end of that bolt also--it is probably history and guess what? you cant just get that part you have to buy the entire caliper bolt!
oldragger

 

Yea the rubber thing is history for sure, any ideas where I can get the bolt besides the dealership? if not does the dealership keep them in stock?

 

Dealership......want OEM parts for brakes..

Not likely an in-stock item. They will likely try to sell you a new caliper

 

i will let you in on a little trick---you can used the correct size heatshrink as a substitute for that rubber stuff on the end of the bolts.. use GOOD hi temp grease on the bolts. replace the rubber caps.
olddragger

 

Got the pin with the rubber thing at the end from the dealership for only 9 bucks. With the rubber boot and overnight shipping it only came out to be 25 bucks. Not to bad I think.

 

Ok, I'm having the same problem, but I cannot get that stupid bolt to slide out. One is still sliding fine, but the one one is stuck in there like its welded. Any suggestions?

Rotors and pads look fine, but I just bedded some rotors so the high heat prob didn't do it any favors.

 

which side?

 

Passenger side, top bolt.

 

Get a new caliper...likely you will never get it unseized....\i've tried with real bad ones and they almost are never worth the work

You might be able to free it with a torch and liberal amounts of penetrating oil and a hammer....but maybe not

 

Its not the caliper, its the "frame" that the caliper bolts to.

 

I manage to take it out but destroyed the bolt in the process. I think its less than ten bucks at the dealership. Soak it in pb blaster and just try to pry it out. Worked for me after a few hours of struggling

 

You should be able to free it from seizing by first rotating the bolt (using slip joint long handled piliers, aka water pumps) and then pull it out. Clean with emory cloth or steel wool and then apply high temp copper grease and re-insert.

Case in point for never letting your calipers get to that state in the first place (preventive maintenance).

 

I know about the preventative maintenance, but even with the pliers I can't get it to turn or move. Going to soak it in some PB and see if that helps.

 

Its the slide the caliper moves on...the two that I have tried to fix never did come loose...even after heating them up with a MAP torch until they were cherry red and beating on them with a hammer....

Talk to Patrick or Mazmart and get a used one.....not worth the work

I think the frame is the same on both sides?

 

preventive maintenance? How do you prevent that? It is a bad design that allows moisture to seep inside and corrode. It should last a lifetime

 

You prevent it by lubricating the slides...and making sure the rubber boot is OK

If you do that you won't have problems.

If you use your brakes around town..you will likely be OK...but if you cook them at the track like I do...the rubber boots crack and break...and need to be replaced. Just like a lot of other parts that weren't designed to be used/abused like that

 

Yea I understand that but this isn't a regular maintenance item. Its not supposed to size after 35k miles or so.

 

Most vehicle manufacturers mandate 15K miles Brake system checks and lubrication. Most people that do there own maintenance tend to forget about the brakes till something fails to work correctly. You should check/lube the slides AT LEAST every time you change the pads

My point was...it you use the vehicle for uses other than intended IE: track days etc....you need to be more aware of the stresses you put on the vehicle by doing so.

 

Yep, I totally forgot about them. However while the car is down, its a great time to go thru and do all that lubing!