I helped my buddy change over to winter tires on Sunday, I get a text from him on Monday saying his- '97 4wd Taco 5spd 3rzfe, manual hubs, no ABS- will not move and keeps stalling. I figured the parking brake got stuck or something. I tell him a long list of things to do.
Later I go over there to help out. I narrow it down to the front driver's side brake. This morning I go back over to bleed the brakes. Doesnt help. No air in the line. I'm able to push the pistons into the caliper and then the rotor is able to spin like it should. I got it to where after he presses the brakes, the rotor is able to spin, but there is too much friction/resistance. After pressing the brakes hard like you would in a hard stop, the pistons won't return. There is a fair amount of brake dust lining the calipers/pistons/pads/rotor, but doesnt seem abnormal. The pads are easily still 6-7mm (new is around 9.5mm, IIRC). They arent frozen, it was in his warm garage all weekend.
Should he just replace the caliper(s)? IS there a way to clean the pistons without TOO much disasaembly? Thanks.

 

It's probably easiest to just replace the caliper. That's pretty stuck, good chance the bores are pretty pitted. Of course you could pop out the piston and see before you get a replacement. I've heard of people having some (minor) luck, pushing the piston most of the way out, cleaning and coating with brake fluid then pushing them back in. Seems like that would be a temporary fix at best though.

Could also be a plugged line. Never experienced it myself but I've heard of it. There's not a kinked rubber line or a dented/twisted hard line, is there?

edit: now that I'm thinking of it, a line issue sounds more plausible. Hard to imagine a piston being stuck in the bore so bad that it keeps the truck from moving but can still be pushed back without unreasonable effort. But I guess the same would apply to the line.

Chris

 

Basically all it seems to be is the pistons are not retracting slightly like they should, especially after a hard press of the brakes. Like pressure is staying in the line.

 

ttt...

 

Probably due to corrosion. I recommend replacing the caliper. Also, you could rebuild it, if a kit is available. It's pretty easy.

 

Does this happen with the other wheels and tires too? To get the piston out, take the piston off of vehicle, set on a bench, find a piece of wood long enough about 1 foot and not too wide 1" and place in front of piston. take bleeder out. cover with a shop towel and use compressed air in the bleeder hole till you hear a loud pop. check for pitting and check the rubber boot and piston seal. You can replace the boot and seal. It is time consuming but it is way cheaper.

http://www.amazon.com/Omix-Ada-16746...6&sr=8-3-fkmr1

Also, check for leaking and possible rust