1992 XJS convertible with the V-12 engine.

Just replaced the calipers. Not a job I would want to do again but I could probably do it in a quarter of the time.
Too much time was wasted trying to find the best way.
You probably should remove the whole rear end assembly but I decided to do it on the car.
You can't do it on the car if you don't have a vehicle lift.
I tried many ways and eventually this is the best - maybe only way.
Remove axle undertray and hydraulic lines. Put a vacuum pipe grommet over end of pipe from brake cylinder and the brake fluid won't leak out.
I used a ratchet tie down over the axle and around the emergency brake levers to compress them so you can slip the cable out of it's sockets.
The first side caliper bolts were so tight I removed the lower suspension pin [14 inches long] so I could get a wrench on it but for the right side I bought a new wrench and with a 3 foot pipe over the wrench they loosened.
You now need to remove the emergency brake assemblies on top of the caliper as you cannot get the caliper out with them attached unless you remove exhaust and other bits.
They are held by 2 long bolts through the caliper and the assembly.
You can see the bolts after the brake pipes are removed.
You will have to wiggle the emergency brake assembly backwoods and out of the caliper. They may be tight.
The caliper can now be wiggled out.
Take the emergency brake assembly out for each side and put a file over the part that fits in the caliper. They are very tight and a bit of cleanup will help.
Put the emergency brake assembly back over disc as you can't get it in after the caliper is in.
I tried putting the emergency brake assembly back in 2 pieces but could never get the long adjusting screw to start a thread as the nut is not trapped and goes out of position.
Fit the emergency brake assembly back on the caliper while caliper is loose on the disc and before bolting the caliper to axle.
The 2 bolts that hold the caliper can go in an eighth of an inch or more without getting to the threads so you can get it in the right position. Put the bottom one in first as you can look up and almost see the hole.
Good Luck.
Norman

 

Excellent write up. The only thing I would add is that if you loosen the nut on the handbrake cable ( just behind the handle under the carpet) you can get the cable off the calipers by hand.

 

Ugh.. Good tech article. I remember watching my dad go thru the rear rear panels to change E type brakes. Just a thought. I've done rears on a XJ-S and it waqs a PITA.

 

great write up from a long time ago. That can help replace the brakes but how would I replace the rotors? Mine are definitely scores and worn.

Anyone can help me? I don't want to drop the whole rear end to replace the rotors. If I can't replace the rotors without dropping the rear then will it be a problem just to replace the brakes?

 

Hi MIFoodie

If you just want to replace the Rear Brake Pads, its quite an easy job to do (in the Scheme of things) without dropping the Rear Cage

You can see how I did mine 3/4 way down on Page 25 of my 'Cherry Blossom' restoration thread

Here is a Link to that Page: https://www.jaguarforums.com/forum/x...122634/page25/

 

I think that I also need to replace the rotors.

 

Its definitely doable with a pair of jackstands. The only thing I removed when I rebuilt my rears was the brakes themselves. Obviously you have to undo the handbrake and brake pipes, but that it.

I imagine getting the caliper bolts free would be way easier with an impact, didn't have one at the time. Bracing my extension while trying to apply adequate torque was the biggest problem I recall.

 

As SS said, quite doable axle in the car. jack it up and place suitable stands and supports under the car and axle cage, but NOT under the hub. Remove the brake pads first and undo the three brake pipe unions joining the callipers. Then you have to undo the four nuts holding the driveshaft to the diff output shaft. Then the driveshaft pulls off the output shaft studs (note the shims position and put them back where they came from. The rotors will be loose, but held by the callipers from actually coming free. Remove the two bolts holding the calliper and then you can remove the disc (rotor).
If you want better cornering and handling, removing a shim from the driveshaft each side to get a touch more negative camber is a good idea.
Greg

 

Removing the rotors with the rear cage in place is possible, yes, but the rear control arms must be allowed to drop wayyyyy down in order to gain the clearance. This means the cars has to be wayyyyy up on jack stands......higher than I'd be comfortable with, personally.

Just my two cents


Cheers
DD

 

I may owe you a nickle. I am uncomfortable changing the rear rotors since I have never done anything with possibly changing the suspension geometry or the suspension pieces, but also understand that changing the pads only is not a good idea when the rotor is rough. Mine has a few concentric scratches and a "lip" on the outside. Since the car only has 30,000 miles and I drive it only about 1,000 miles a year, maybe I should just put it off and wait a few years, and move on to other cars? What do you all think?

 

The rear brakes don't normally have to do much work so provided they still function as intended l don't see an issue with waiting a bit. I've come across cars where the pads were actally jammed solid in the caliper and the owner unaware of it.

 

Thanks. I think that I will change the pads, since I have them, and not bother with the rotors or the emergency brakes.

 

I can' tell if you misunderstood what Doug said, but you don't need to do anything with the suspension geometry. He was simply saying you have to get the car high enough up that the wheels are sagging as far down as possible in order to get clearance to remove the half shafts and rotors. Either way, there isn't really anything involved with the suspension going on in he job. The worst part is the calipers have to come back out lol.

 

I raised the car further in the air on several strong jack stands, about 20 inches, and checked that it is very sturdy. Taking a good look underneath with a strong light I think that I can see what is needed so I will try to change the brakes and rotors. Wish me luck.

 

Dropping the rear cage isn't hard nor time consuming. I'd drop the cage if your replacing rotors.

 

OK. I gave up on trying to do the rear rotors without removing the IRS and now am disconnecting everything and dropping the IRS.