I had a sticky rear caliper on my WJ Grand Cherokee.
Bought new pads for Teves along with Crown replacement piston and ring type seal
Stripped caliper, ejected sticky piston [It is showing heat damage and a small crack in the bearing surface.]
Old seal looked same as new not swollen!
Cleaned out chamber lubed with fresh fluid and tried piston without seal.
Piston would not enter past chamfer/seal groove ??????
Diameter too big Interference fit !
Compared with old piston .... appeared same except slightly shorter
Did not have a means to measure accurately at the time.
Needed to be mobile so cleaned old piston and polished with 600 wet and dry and tested fit ..... no sticking so reassembled as temp measure with new seal!
Contacted supplier who will send replacement if I ship the piston back to him but the problem remains.......
The box says Crown Automative replaces 5011983AA but .... Is the piston in the right box or are my calipers non standard?
Can anyone tell me what dimensions the piston in the rear caliper should be?
I cannot measure the existing without stripping everything again and putting the jeep out of service and sending the non fitting piston back for swap may be pointless!
I seem to remember the old piston has KK7 embossed on the bottom but the new one is unmarked so size will be the only identification!!