86 740 frt brk hanging up

nisan17 · Post by **nisan17** » 18 Apr 2008, 22:19

Hi Group,

My driver's side front brake caliper is hanging up. When the car is jacked up I can turn the rotor, but takes two hands(with tire off)

I just recently replaced the rotor/pads as the pads wore out and the pads/plates grooved the rotor. At the time of changing the mechanic said the caliper wasn't sticking. Now I believe it is sticking, my mileage went from 25-26 mpg to 22 mpg. Plus, the rotor warps when driving for long periods of time and the wheel is hot to touch sometimes.

Question: Is there a quick way to free up the pistons? A couple mechanics and parts guys say it's easier to replace the caliper than to rebuild it. I'm thinking if I can just pull the pads out, pull the piston boots back and spray some penetrating oil in, we'll be alright!!!

I've had worse with domestic cars, where they wouldn't allow the wheel to turn at all.

What's the general opinion?

Thanks in advance,

Post by **jonesg** » 19 Apr 2008, 09:17

I'd pull the caliper and clean the piston and bore with 000 steel wool and brake cleaner, hand fit and check. If they're pitted or show wear such as ridges or scoring then its better to swap em out .
If you do it get brake fluid beforehand.

The mechanic is talking about whats easier for him, not cheaper for you.

nisan17 · Post by **nisan17** » 19 Apr 2008, 17:42

Well,
I checked the pistons by pulling back the boots...and I saw a couple of pits. I sprayed some penetrating oil under the boot to buy me some time till I pick up the caliper I ordered. The one piston was pretty well hung up or seized. Took a whole lot of squeezing to move that baby in.

My boots were in really good shape...how could the pistons get pitted? ooh well.

Thanks again

Post by **jonesg** » 19 Apr 2008, 20:05

I find it easier to put a peice of plywood in the caliper and press on the brakes, that usually pops the piston loose.