Trying to Replace Rear XJ8 Brakes but they are stuck to rotor

I tried again this evening with no level of success. I even heard the emergency brake lever move. The pads were still as tight as a drum. I agree the lip was probably partially the culprit, but it was still too tight to move. Believe it or not, I actually changed the rear brakes once before on this car. I will admit I forced the rear calipers off that time (probably due to the lip). I wasn't quite as willing to smack it around as much this time. I was hoping for the miracle release point. I appreciate all of your help. I think I will just stick to working on non Jags (I can at least handle that still). I will have to defer to people smarter than I am for the Jag repairs. I will help keep Jag Repair personnel in business.

Thanks again. I really appreciate your time!

Just to be clear, 2005 and 2006 Electronic Parking Brake systems are different. Different control modules and calipers entirely. Overall they operate basically the same though. Technically, the brake needs to be released to the 'service position' before the rear pads are changed, but it can be done without that.
I would guess the calipers won't come off because of a ridge in the rotor. So they may just need to get a little help in the form of a lever to force the pads over the ridge. Once off, the caliper piston has to be screwed back into the caliper housing with a special tool for doing so. They can be had at most auto parts stores. [the tool to engage the piston is different, 2005 to 2006 also]

Once the piston is retracted and pads installed and all reassembled, the pedal has to be pressed repeatedly to extend the pistons to the rotor. Then the battery must be disconnected for a minute. This takes the place of the equipment releasing the brake to the service position. Once reconnected and the ignition turned on, the instruments will instruct you to press the brake pedal and apply the parking brake; that will re-initialize the park brake to the new pads. Apply and release the Park Brake two or three times and your brakes are good to go.

A little more involved than you thought, huh??

Cheers,

Patrick,
One more step-in here-----------

You said above, that you put everything back together and the car drove fine. I did some test on my car, as I said I would for you and can tell you for sure -- that if the rear calipers weren't releasing the rear brakes, you wouldn't have moved the car at all. When your trying to replace your brake pads, your doing something wrong pal and you need to get some help, before you really screw something up. IMHO!
Just some friendly advise.

Chuck

05/XJ8L

I may try the two wheel off approach tomorrow. Otherwise, for sure this weekend. It seems too much like the emergency brake is still on, even though the dash light says otherwise. Thanks for the help. I'll let you know what happens.

Edited on 2012-06-11 17:18:54

There is a screw type mechanism in each rear caliper. When the Brake actuator pulls the cable and lever I mentioned tight, the piston screws out to pinch the rotor. This is a separate function from the normal hydraulic application of the service brakes.

Cheers,

When I couldn't get the caliper off the rotor, I put everything back together. I have been driving my car the past couple of days without a problem. I was only working one wheel at a time though. I actually started the car, and released the emergency brake. The light went off, then I moved the key back to the accessory position. The cable for the emergency brake does not seem all that tight, so I would think the pads would not be so tight. Does the emergency brake cable manually engage the piston in the caliper, or does something else engage the piston to be active? Thanks for your help!

Edited on 2012-06-11 12:38:20

Patrick,

What you need to find out is whether something has caused the brake to stay applied, even when the actuator has "released" the brake. It sounds as though it is releasing, but the caliper is not. If you remove both rear wheels, turn your ignition on and press the brake pedal, then pull up on the Park Brake switch. Now check each rear wheel and note the position of the lever attached to the back side of each caliper. Then press the brake pedal and press down on the Park Brake switch to release the Brake Actuator. Now check the caliper levers; if working properly, they should have relaxed and rotated toward the front of the car. If they have not, something is stuck or seized. If they did relax, there is either a problem with a caliper or slide pin most likely.

Were you having a problem driving the car before you noticed the brake "not releasing"???

The car was mine in 1966/67. When I finished it, it was as you see.
See my note on the car in the mkll section.
tomorrow I am going to try something with my car to release the brake's, if it works I'll let u know. I also asked steve to drop u a note.
garfield

The emergency brake works correctly during normal use. It also appears to be "releasing" when I turn the car on, put it in neutral and manually push the emergency brake switch down (the light in the dash goes off). The confusion, is that the pads are gripping onto the rotor for dear life, and will not let go. It seems like the emergency brake is on, but maybe it is something else.

By the way Garfield, if the picture is your car, it is a beauty.

Funny thing Pat. Your problem brings back memories.

When I was the proud owner of the MK VII pictured to the left, I remember it had a "parking brake" feature that once you turned off the engine, the brakes would lock, preventing the car from rolling----a lack of vacuum thing. This almost caused me to loose the car and my home because of a fire in the engine compartment--which I started while removing the carburetors . Although a neat feature, not a safe one IMHO.

Garfield

05/XJ8L

Pat,

Hold everything, it's the week-end and the one's that know for sure are more then likely not reading the forum.
I say this, because I don't want you to do something you'll suffer from later. I'm sure it's something simple, like just pushing the calipers apart, or as you have tried, releasing the emg brake.
Hopefully, someone like Steve Petry will answer your call.

Chuck

05/XJ8L