I have an 05 base TL and my rear passenger brake froze about 6 months ago. I changed both rear calipers, rotors, and pads. I was driving the other day and the same, rear passenger side brake froze. My other brakes are fine and my pedal is still firm. The fluid level is fine. The only thing I can think of is a bad hose? I checked the hose and there are no leaks. Why would just the rear passanger side caliper keep seizing?

 

FYI, I could not move the piston at all on the old caliper when I took it off. Maybe I just had two bad calipers. Seems like a small chance though... If it seizes again, what test should I do to narrow down where the problem is?

 

Did you use an OEM caliper (NEW or RMD)?

Any water in the lines will cause corrosion inside the caliper. The recommended replacement interval (full flush) for brake fluid is three years. I like to bleed out the calipers once a year. Water/moisture from the atmosphere is absorbed from the caliper end of the system.

 

If the line has an internal break, it will leak no fluid but will disrupt the flow of fluid back to the MC and therefore not allow the piston to return. Next time it occurs, pull the caliper and try to push the piston inward, if it doesn't go, open the bleeder and try again. If it then moves inward, bad brake hose. Also, make certain all sliders are working properly, cleaned and greased.

 

I actually had this happen to me on my '86 Trans Am. Passenger front brake seized up, so I replaced the caliper, pads and rotor to no avail. Turns out the rubber brake line collapsed internally. Replaced the brake line and all was well.

 

Just keep replacing calipers.

But seriously, Turbonut nailed it. A collapsed line will allow the higher pressure from the MC through but will only bleed off so much pressure causing the brakes to stay on.

On the last one that failed, did you try moving the piston once the caliper was removed from the car?

 

Thanks for the advise guys. I did try moving the piston on the last caliper I removed and I could not move it. I am going to replace the brake hose and flush the fluid. I have never flushed the brake lines before. How do you know how much to flush out of each line?

 

There's part of your problem, an 05 that has never had the fluid swapped out. There's likely a large amount of water in the line. If you couldn't push the piston in with the brake line disconnected and the bleeder open for good measure then the actual problem was the caliper but the cause was likely condensation in the brake line. I would almost bet you could flush it really good and get away with not replacing the brake line but its probably better to just do both since brakes are kind of important.

If you want, open the bleeder on the current frozen one and try to push the piston back in if you want to be sure the caliper is actually frozen.

 

Typically, you flush until you can see clean, clear fluid coming through the bleed hose.

 

I could not push the piston in on the new caliper. I released the bleeder and it went right in. I replaced both rear brake hoses and bleed the system. Hopefully no more problems. thanks for the help

 

Glad it worked out, but just wanted to mention for future reference or readers, never clamp the brake lines with vice grips or a similar tool to keep the fluid from draining out. When the hose is compressed by the tool it will break, or could break the internal structure of the hose.

 

I found if you put the cap on the brake fluid reservoir the vacuum will hold most of fluid in. I did not have much fluid escape while i changed my hoses. Good point though Turbonut.