Inner Front Caliper Piston is way out

[logdrum]

Hi all,

I may not have searched properly but I cannot find info on how to compress the inner piston of the front right caliper on my 1983 W123. The pads were worn unevenly and the inner pad was almost bare metal. The left brakes were a breeze to replace but the right wheel was different. The piston needs to move ~2mm for me to be able to slide new brake pad in. I used the old pad and used one of those adjustable pliers to push the pistons in. Is the caliper shot. I open my brake fluid reservoir cap as well. But it is really hard and won't budge

C-Clamp needed right? Any way to diagnose if the the caliper piston is shot.

BTW I replace the left brake without removing the caliper. The wheel in question the rotors are the same thickness as the left and not scored on the inner side.


Thanks


Thanks

[Diesel911]

Sounds like one of the pistons is sticking some and the other is doing the work.

Shoving them back in without pulling the Pistons and cleaning the muck out of the Caliper Piston Bore is not the best idea.

The Caliper Pistons need to be pulled to visually inspect them in the areas where the Caliper Seal rides. Look for pitting and peeling plating (if they are Chrome Plated).

However, it is the Caliper Piston Bores that often are rusty (sometimes enough to cause the Caliper Piston to stick) and pitted as they are seldom have the protection of being Hard Chromed like the Calipers Pistons often are.
Some scattered pitting is OK as long as long as there is not a large area eaten away.

And, as long as the pitting does not extend into the Caliper Seal area enough that you think it would leak.

[vstech]

if you get one side on, then put the old pad in the side with problems, then pry against the rotor with a large screwdriver, it will usually go in with a bit of force.
I agree, getting a rebuild kit and inspecting the piston bores is a good idea.

[logdrum]

Thanks guys. I found the caliper dragging thread. I made a bigger mess by breaking the caliper bolt. Tried the easy out extractor method method and I am not doing too good. So I have to bring this car to the shop because I can see that if I start stripping threads then it is going to be a bigger problem, unless you guys can guide me to a broken caliper bolt rescue.

Yeah it needs a rebuild. I bought a tool to push it back ( and thinking that I may need a rebuild ) but broke the bolt in the process