I am attempting to replace the rear brake pads on my 1987 Jaguar XJ6 Vanden Plas. Does anyone know if the caliper pistons have to be wound in or can they just be pushed in? They don’t seem to respond to just pushing. If they need to be wound in, is there tool for especially for the Jaguar? Thank you.
You’ll want to get hooked into a Jaguar forum for this and all the other questions about keeping an old Jag on the road.
Look on the caliper piston face for features such as slots or holes. If there are such a feature then the pistons need to be rotated back into their bores with a tool such as this.
If there are no such features then the pistons are compressed back into their bores.
Does the parking brake cable attach directly to the caliper?
If it does, you might very well have to wind the pistons back into the bore
Don’t know, but if they are supposed to be pushed, opening the bleeder valve on the caliper will make it easier. On some cars w/ABS, I’ve heard say that pushing the pistons in without opening the caliper bleeder valve can damage the ABS unit. It forces the brake fluid to go backward, and the ABS unit isn’t liking that I guess.
Try here, it’s the best site for Jaguar owners I’ve ever seen:
Thank you to everyone who responded to my question. After spending most of the afternoon today pushing and shoving with various improvised devices, I was finally able to get the caliper pistons far enough back to install the new brake pads. The pistons do not need to be wound back since, as was suggested, the parking brake has its own set of pads.
Something to keep in mind is pistons that are difficult to retract may be that way due to aged, hardened piston seals in the calipers. Technically this means the calipers should be rebuilt or replaced.
It would be a good idea to keep an eye on the brake pads for premature wear or symptoms such as brake shudder/pulsation.
+1. That’s especially true with any 25 year old car, and doubly so for a Jaguar.