Any trick to getting a frozen caliper off?

[TerryMason]

I'm trying to do a brake job on my TJ, but I'm having problems just getting the caliper off. The rotor is worn down, so there is a lip around the edge - I can't just pull the caliper off, the pads catch on the lip. I can't use a c-clamp to depress the piston, because the rotor is still on.

I'm getting new caipers, rotors, and pads, so I may just end up taking a long pry-bar and going medieval on it, but I was wondering if there was an easier way.

 

[JPNinPA]

Not really. I leave the bottom bolt of the caliper in but not tight and pry the top of the caliper off the rotor. The bottom bolt is a hinge point and allows good leverage on the top when you pry. You could hit the rim of rust with PB blaster to dissolve it, if it is all rust.

 

[greg92jeepxj]

Agreed , there really isn't any quick way since the caliper piston is frozen and a conventional C - clamp won't handle it . Ball joint C-press may cause destruction . The outer edge of the rotor can be ground with a die grinder since your swapping them but reaching the inner edge of the rotor may be tricky since the backing plate is real close and we don't need to hack that . Maybe grinding one edge may allow you to get the pads to slip over since your gaining some space and the pads are pretty much set in one width dimension wise and may allow the caliper to come off. I'm not the king of rigging a fix but in a pinch , I'd give that a shot. Trying to open and remove the bleeder to extract the brake fluid to fill the chamber with PB blaster to break up the rust would be time consuming and tricky . Might as well try the die grinder ? Frozen Pistons don't like to play nice .

 

[Bounty__Hunter]

Try to get a good penetrating fluid like PB Blaster in to the caliper piston.

 

[69jeepcj]

I have had to do the same, using large pry bar. It didn't hurt the rotor even though I was replacing it anyway, tore a chunck of the brake pad off is all, or what was left of it.. using a small pry bar and taps with a hammer may do the trick.

 

[Dragon5126]

Ive used hard wood wedges, all steel wood chisels small wrecking bars flat metal pry bars... Just remember to open they master cylinder reservoir first then use a dead blow mallet to drive whatever wedge you are using between the pas and the OUTSIDE of the disc. it should free up the piston never pry directly against the piston itself. I don't know when they started but I discovered on my 06 that the piston is ceramic when fluid started leaking THROUGH it when after being up 48 hours straight I used the wrong size anvil on by disc brake compressor and scored the inside the piston... Once the piston starts moving you can pry between the inside pad and the disc they usually free up with out damage the easiest way to test is a piece of wood the thickness of a good disc between the old pads in the caliper (like oak from a pallet) put the cap back on the fluid reservoir and have someone pump up the brakes and inspect for leaks and see if the piston moves back with minimal pressure.

 

[TerryMason]

I ultimately did what JPNinPA described and used a prybar to power it off. I unhooked the brake line from the caliper first to drain all the fulid, and since I was replacing the caliper, rotor, and pads, I just pulled and cussed until it came off.

Thanks guys.

 

[superj]

i just use the big screw driver trick also