help with brakes!
help with brakes!
I just put new pads/rotors up front and pads in back. When trying to reset the piston on each side it would not budge. the only way I could get it back in waswith sime vise grips. I peeled the rubber back on both pistons and there was some rust. The pins that are supposed to be greased were completely rust in place. I had to heat them up with a torch and hammer with a chisel to get them loose. I sanded those, greased and reinstalled. I got everything hooked back up, drove around the block...no problems. Drive about five miles to the store and I smell burning brakes. BOTH rear wheels were hotter than p!ss, meaning the brakes were probably red hot. Are my calipers shot? when I took each rear wheel off there was a decent glaze over both rotors and pads.
Re: help with brakes! (ehacker01)
.ehacker01 wrote: the only way I could get it back in waswith sime vise grips. I peeled the rubber back on both pistons and there was some rust.
It's OK for there to be slight rust around the top of the caliper pistons, it's when it gets thru that rubber seal that it can rust/sieze the piston/walls. Could have been OK: problem is you probably boogered your rear calipers anyways by compressing them with a C-clamp. Nail in the coffin. You need to turn the piston itself with a pair of needle-nose pliers clock-wise to turn them in. Try doing this. If it's extremely hard to turn, consider it shot. Your hydraulics may be able to push them out, but they're of no use if they can't easily return.
Those slider pins that you sanded: make sure the rubber boots are in good shape or you'll be back to the same place shortly. When you install the slider pins/boots, press them in as far as you can, compressing the rubber. While compressed, pull pack the rubber at one end just enough to hear a 'pissh', letting the air out. It'll help keep a better seal for a little while(won't last forever, but it's just a habit of mine).
I didn't use the vise grips to reset the piston I actually used them to grab the needle nose pliers so I could get some leverage. Guess if it took that much for them to turn that would qualify as "extremely hard". and the rust was inside the rubber boot of the piston. I pulled it up to see if it was fused together or not.
Re: (ehacker01)
i know the needle nose trick works, but you can get the piston pusher tool from harbor freight like $20. maks the process a lot easier.
Re: (ehacker01)
It shouldn't be that hard to turn in the rear calipers. I did it using just a pair of needle nose pliers, but a little caliper tool (cube thing that fits on a 1/2" extension) made it a lot easier. It really sounds like one or both of those calipers are seized.ehacker01 wrote:I didn't use the vise grips to reset the piston I actually used them to grab the needle nose pliers so I could get some leverage. Guess if it took that much for them to turn that would qualify as "extremely hard". and the rust was inside the rubber boot of the piston. I pulled it up to see if it was fused together or not.
As I recall, you can use some fine emory paper on the cylinder walls, but not the cylinder itself. I suppose you can take it apart completely and look for heavy corrosion, pitting, scoring, etc. on the cylinder piston. It sure sounds like the easiest thing to do at this point is just pick up one (or maybe even a pair) of remanned calipers at Autozone.
Re: (BadMojo)
^^ I'm with him... and yes the piston surface is plated, so don't use anything harsher than a shop/paper towel to clean. Use brake fluid to clean them up: it'll take off a lot more than you might think. I used a small wire brush to remove rust around the top of the piston(only where it protrudes the cylinder).