Caliper Pistons Frozen or?
 

I've read many threads about brake caliper pistons being frozen and that it is a common problem on these models.

I'm in the process of replacing the pads and rotors on my 2003 GX470 (about 150,000 miles). When I got the caliper assembly off of both front sides, the outer pistons compressed easily but the inner pistons did not. The procedure I followed didn't disconnect the brake line nor remove any bolts other than the two bolts that hold the caliper assembly to the car.

Do I need to remove any of the other four bolts to get those pistons back in? I've hear that I should take the cap of the fluid reservoir and try again.

It just seems suspect that both inner piston sets do not retract. I didn't go ape on the c-clamp, but I don't think I should have to do that.

Any thoughts before I investigate re-building the calipers or get replacement?

By the way, I got a crazy good deal on brakes and rotors at Advance Auto. I know the purists wouldn't agree, but I'm more pragmatic with things. The top of the line that they have for pads and rotors for all four wheels was barely $200 with the discounts I managed to get... Lexus wanted $1400 for the brake and rotor job.

Thanks for any input...

Look at the reservoir and see what the level is. If you pushed the outer pistons really far in, the fluid might have filled the reservoir. So you'd have to remove some with a syringe or turkey baster. Replace any fluid with fresh when you're done (stock fluid is DOT3).

Of course, it's also possible they're frozen. Make sure they're lined up before pressing in, of course. Check for corrosion. But their time might have come...

Chip H.

Looks like it was a bad/frozen caliper piston. Took it completely off and was unable to move one of the pistons. Replaced the caliper and all is well on the front. Tomorrow - the back brakes and rotors....

Thanks.

Did you look into rebuilding the calipers? It might be nice to save money and know that your caliper was fixed correctly.

Nothing wrong with auto parts store rotors/pads .. just a little higher chance you'll have to service sooner than the top brands. I've never done it but I hear they sometimes have a lifetime warranty. Can apply to rebuilt calipers too. If you're one to keep cars forever it'd mean you only pay for a brake job once. Despite the best intentions at time of purchase most people end up replacing their cars before that becomes useful...

I just order things from rockauto .. can't go wrong with centrix rotors and akebono premium pads.

I have a gx470 05 model. While attempting to remove my rear rotors I get stuck, or they do. I've used the jack bolts and there is movement of the rotor but only a couple mm. I realize it's the emergency brake pads holding on to the rotor.
Now im afraid to force the screws as the may strip. Yes I've release parking brake.
Any experience such as this? Your help, or direction would be greatly appreciated. freddiekd

Yes, I had trouble removing my rear rotors because of emergency brake. After forcing it, I had a pin pop out and took me an hour to figure out where it came from and how to reinstall. Anyway, there is a hole in the rotor which allows you to access a small dial that you can rotate up or down with a screw driver. I can't remember which direction tightens emergency brake and which loosens, but it should be evident as tightening will cause you to be unable to rotate rotor if u momentarily placed in neutral (with wheels chocked of course!). If you loosen, the emergency brake retracts and you should be able to remove rotor. You will just need to adjust again after installing new rotor.