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So I've been replacing pads and rotors last weekend and got completely stuck on the rear left caliper: the piston wouldn't fully retract. That's Accord that I'm talking about here, and pistons are supposed to be rotated clockwise, not just pushed back, but this one wouldn't even move initially.
I've spent quite a few hours trying to push it in, rotate with a screw driver, a crowbar, and was eventually able to get it unstuck by slamming the brake pedal. Then the cylinder started to move a little, turn, first with force, then gradually easier and easier. Eventually I was able to almost completely screw it back, but then it got stuck again.
So, today I went for a tool at Autozone thinking that it had to be better than a crowbar. It was, but not quite. The piston still wouldn't go fully back in.
I then noticed that the rubber boot detached from the caliper body, and duh, the piston was all rusty, as in the picture.
After removing the boot completely (it looks OK, not torn) and some sanding, hooray, I was able screw the piston fully back, but now I have a dilemma.
Should I even bother with this caliper now, or should I just scrap it and put a new aftermarket one? It seems that a fluid flush is unavoidable. In order to put the boot back I need to fully remove the piston first. I think I will be able to do it w/o disconnecting the caliper, but removing the piston will let the fluid out anyway. The good part is that I'll be able to clean the rust better than now.
At the moment the brakes work, the caliper isn't seized, the wheel brakes and then freely rotates just fine, it's just that the piston is all rusty, and the rubber boot is still off.
What do you think? Remove/clean/reseat the piston? Replace the caliper?
To be honest, at this point, if you were to fix it, it would only be temporarily. I had this issue 2 years ago, i tried my best, ultimately the caliper got stuck pressing on the pad, it not only made me use more fuel, the car wasn't driving straight and the affected wheels pads were much more used up than other side. The TLs calipers aren't made to be refurbished, plus, you can get a new pair for 100$.
The part of the piston you see is outside the piston seal, inside is where the problem lies. When the piston is turned and becomes tight and won't move in any further, same as a piston that is pushed in and becomes tight, it's time for a rebuild if you can do it yourself, or most will just replace the caliper with a remanufactured unit. I would also make certain the other calipers are in decent condition, but if not, might as well do what ever is needed at the same time.
Yes, I do believe that removing rust from the piston or getting a new piston would suffice. I swapped the caliper yesterday and out of curiosity opened the old one up. Other than very murky fluid, it all looks fine on the inside. Could've saved a few $, plus wouldn't have to deal with readjusting the ebrake. It doesn't work on that wheel now, LOL!
let me take a guess that you living in the northern state? it happened to me every year and one piston bad enough that the salt eat through the piston.
After looking at the piston and reading the replies I see the rust is on the outside that must have been from a broken boot. I've lived and worked on cars in the NE my entire life and haven't encountered a problem like this, of course haven't had any with broken boots. Many pistons would seize, but that was on the inside of the bore from contaminated fluid.
Well, at least you've got it repaired.
10-05-2015, 10:10 PM
