I have a ‘78 manual XJS which is a great car except the handbrake is now useless, and it makes it practically undriveable (as a manual in a place with lots of hills…).
I have studied pictures etc. and gather that there is no point adjusting it by the driver’s seat, but instead you have to use the primary adjusters by the IRS.
I have put the car up on axle stands and can see the handbrake calipers although most of the mechanism is out of view. Having a rummage around I found this loose fragment sitting on top of the main brake caliper (on the LHS).
I have a horrible feeling this is part of a handbrake pad and that, if the pad has disintegrated, it is no longer a matter of adjustment but if removing the handbrake calipers to renew the pads…
Would you agree this is a handbrake pad? And if so that I will need to renew them (at least on the LHS)? Does that require dropping the IRS…. I just can’t see how you’d do it when you can barely see the mechanism at all.
Sure looks like pad material. When I removed the cage on mine to do the output shaft seals, one of the park brake pads had lost it’s lining. So not unheard of. I don’t know how you could possibly do it on the car.
Sideshowbob
(Robert Moore 90 XJS V12 Convertible Marelli)
3
That definitely looks like a brake pad from one of the parking brake calipers.
I just replaced all the brake components on our 90 XJS. I educated myself by googling XJS removing rear calipers, XJS Removing rear brake calipers w/o removing cage ect.
I spent a lot of time researching the job as well as collecting all new main calipers, brake pads, rotors, park brake calipers and pads, mounting pins and bolts, springs ect.
I purchased so many parts so I would hopefully never have to do the IRS brake job again.
I did complete job in less then 8 hrs on a hoist without removing the cage.
Good Luck!
I don’t know if you are agreeing with each other…?
Robert you seem to say you’d need to drop the IRS. Bob I think you are saying you did drop it, but not completely (I am not sure what you mean otherwise when you say you used a hoist)…?
You don’t need to drop anything, the rear brake calipers are pain to pull out, not the handbrake jaws. These are easily accessible from the bottom, being attached to main caliper with 4 stainless steel anti-seize bolts from factory. Handbrake pads are snapping off easily with use of chisel, new set of thses small pads approx £30. While you have your handbrake mechanism out - it is worth mentioning that there are mechanical bits and bobs under metal covers - in need of your love and attention. Worth replacing brass spring forks as well.
Janusz nailed it, I bend back the brass springs and all went fine on two cars - unless you break one. Better to order some. I drop the IRS if the exhaust allows and it will take at least a day if it’s your first time. I‘d try it in the IRS now if the exhaust is in the way but for a first time it’s easier with the cage on the floor.
Grease everything up and adjust them parallel to the disc with some gap. The pads do delaminate eventually and if you lose just one it’s over.
Sideshowbob
(Robert Moore 90 XJS V12 Convertible Marelli)
7
I did the complete rear inboard brake job, rotors and all, without dropping the cage.
As a side note when I did the brakes I first removed the park brake springs and cable, then removed the park brake caliper mounting pins and then I slid the park brake calipers forward out of the way. I then removed the main calipers followed by the park brake calipers and they were easily removed without the main calipers installed
If I recall, the previous “tech” had misaligned the fork when installing the bolts/pins and missed one of the holes, which resulted in the broken pad. From trying to do it in the car I believe. Dropping the cage isn’t hard, I was doing the output shaft seals when I found the issue.
It’s definitely a piece of the handbrake pad Adrian.
Not the first nor the last, and not sure how long the new ones will last before braking/delaminating again. In my case it was a couple of weeks…!
There are two ways going about it:
Drop the IRS, but then it would be worth doing a general revision in everything, with the danger of becoming a much bigger job than anticipated.
Really worth it if you you have oil leaks, worn rotors, sloppy/noisy bearings or bad U-joints.
Do it in situ, with lots of laying on you back and dirt coming down in your face while scraping your hands and cursing heavily, very fiddly but totally doable.
Brass forks can be annealed (red hot) and carefully bent back without breaking and will work fine.
Make sure to service/lubricate the callipers adjusting mechanism. Details in the Book.
As I said, the hand brake pad design is seriously flawed.
I seriously recommend buying a set of pads from a small car and cut them to shape, drill a hole and tap a screw to hold them in place.
Did this ten years ago and I have a handbrake that actually works, I can leave the car on a downhill in drive, go buy cigarettes, come back and the car will still be where I left it.
It sounds as though this is a job I can attempt without removing the IRS. And if I understand Janusz properly - also without removing the main calliper?
I am going to have a fiddle around and may be back here for counselling in due course.
I have had a look and things make a lot more sense.
I can see how if I prise back the locking tabs in the two bolts that secure the fork to which the handbrake caliper is attached, that the handbrake assembly comes off fairly easily.
I had removed the exhaust section from the IRS anyway because the centre pipe and intermediate muffler need to be renewed. That helps a little with access.
But I think David’s advice may be relevant here. The LH disc is covered in what is presumably hypoid oil and I think I have a weeping output shaft on the final drive.
So it looks as though I need to bite the bullet and drop the IRS. Here is a picture - thoughts welcome…
One final thing. I can’t see how I release the handbrake cable from the handbrake caliper levers… any tips?
Sideshowbob
(Robert Moore 90 XJS V12 Convertible Marelli)
15
Once you remove the the hand brake caliper return springs the tension will be off the cable and you should be able to remove it from the caliper slots.
I also soaked the cable ends in penetrating oil for a few days before I did my brake job.
It also looks like the rotors have been changed already as they dont have the OEM wire around the circumference of the rotor.
This is the only pic I have of my completed job of complete rear brake component replacement.
That’s a pretty serious leak there Adrian… You have to bite the bullet indeed.
The exact reason my car failed inspection and why I dropped and overhauled the IRS.
It’s up to you to decide how deep you want to go, I went for the full monty as I didn’t want to have to drop the cage again any time soon.
in regard to the handbrake cable: I just finished the same job and in addition to what Bob recommended I also released the “slack adjuster” for the handbrake cable behind the rear seat. That helped a lot.
I am lowering it gently onto a motorcycle jack and checking for any issues etc.
All looks good - except the prop shaft hasn’t detached from the diff flange (I have removed the 4 bolts of course…).
A whack with a mallet hasn’t moved it.
Is it a flush fitting and it will break loose as I drop the IRS further? Do I need to detach it in some way (I have tried pulling the jack back as far as I can to try and work the diff loose).
I thought I would ask before going for it and breaking something…
Try getting a sharp wood chisel in between the flanges (I’m a tool maker, wood chisels don’t cut it for me😹) give it a good rap with a hammer, it should loosen. Replace a bolt to stop it suddenly falling on any tender bits!
