Hi there,

THis is my first post here and I am right in the middle of changing out my rear brake pads in the 89 XJS. I removed the 2 pins to slide the pads out but can't seem to get them out. The jag mechanic said I would need to spread them apart but I keep trying to push them into the pistons but they won't budge. I'd greatly appreciate any advice as to how I can get the pads spread apart far enough in order to get them out?

Also, is there any other info or diagrams on the internet I can look at to help me sort this out?
Thanks in advance for the help.

Cheers,
Christian

 

I pulled my rear end out last week and my pads pushed back with my fingers. How worn are the pads? You could try and use a wood door wedge. Don't use a screw driver or anything metal or you will damage the disk unless they are worn and need replacing.

If the wedge does not move the pads you might have seized pistons or if the pads are totally worn away the piston might have come too far out of the bore. Either way it will require lowering the cage

 

My money's on seized caliper pistons. Hope I'm wrong.

Cheers
DD

 

Thanks guys, Well, I think that one caliper's piston is stuck. Does that mean that I'll have to take apart the whole rear suspension?

 

You can get the caliper off with out removing the rear suspension. After you get the bolts out you have to slide it around the rotor to the bottom. If i had to do mine again I would drop the rear suspension, but then I had to change my rotors.

 

Thanks for the advice. I am wondering, since it is an ABS system, if perhaps the pistons aren't seized and there is a different way to get them to retract back into the caliper? I heard that one has to use the bleeder valve to get them back in? Is that true?

How difficult is it to get the caliper off without removing the rear suspension? Also, is getting the rear suspension off a difficult procedure? I'm fairly good with these things if I have directions, any recommendations?

Cheers,
Chris
89 XJS Rouge Edition

 

There is nothing in the ROM in the ABS section on replacing the pads so the procedure will be the same as non ABS.

I have not removed the rear calipers with the rear end in situ. Mine were removed with the rear end out and they came away with ease.

Removing the rear is not difficult the hardest part is separating the radius arms. The rear comes out with 10 bolts, drive shaft, brake and hand brake connections, oh and speedo drive off the diff depending on model. If you do remove the rear be careful it is mighty heavy I would estimate over 100KG

Just be prepared for the cost, I removed mine to replace shocks and give it a clean. I have now stripped the underbody to bare metal and in the process of stripping the cage, rebuilding the hubs new bearings and bushes in everything and a diff rebuild including a ratio change. So what started out as a $600 job has ended up 4 times that. Oh well I'll never have to do it again.

 

My advice is to drop the rear suspension cage, so you can work in comfort on the brakes.

So awkward were these brakes to service that on earlier cars, Jaguar put an access panel in the back of the trunk compartment. I don't think the XJS has this, however. To drop out the cage, you need a good high lift hydraulic jack to hold it up whilst you undo all the bolts etc, then you gently release to lower the cage to the floor. Previously you will have used this jack to get the car well into the air and onto stands to support the rear of the car. The rear jacking points are the obvious place. Exhaust has to come off as well.

I had a stuck piston that eventually caused the disc to heat up so much it fried the piston seal and the diff seals. It is also likely your handbrake mechanism need servicing the discs are worn out. Have you measured the disc thickness and compared to the quoted miniumum ?

 

Thanks for the advice,

The rear discs definitely need to be changed, so I have ordered the manual to contemplate doing this. I've heard it is a very difficult job, and I know nothing about rear suspensions. But the mechanic wants something like $900 in labour just to do the rotors, so perhaps I should learn quickly. How hard can it be? It's quoted as a 10 hour job.

I reckon I ought to rebuild the pistons on the calipers as well. I think they are shorting out my car's electrical system, as I can hear the radio blurp every time I put on the brakes, and now my battery dies every time I leave it connected. The seals are broken on the pistons and they won't move. Was just going to put brake pads in to make it safer to drive until my rotors and manual comes in. Is there a way to retract the pistons even if they are out too much? Do I need a caliper rebuild kit or just order new calipers?

Thanks for all the advice everyone. It's greatly appreciated.

Cheers,
Chris
89 XJS Rouge Edition 53K mi

 

It is not difficult but some of the bolts can be hard to loosen, I have an impact air gun which made it easier

The brake calipers will not be your electrical problem that will more than likely be bad earths.

Have the calipers rebuilt by a professional if you are unsure remember the brakes are what is between you and the scenery or tree.

 

Just finished my brakes, front rotors and rear pads. Thanks for the info everyone. It was quite a job.... Getting the shims back in the front is a time consuming procedure.

 

I understand that some XJS had an access panel in the boot to get at the handbrake pads? anyone got details of this? can it be a retrofit - anyone got a drawing of this panel?

 

No access panel. Couldn't be in the boot/trunk anyway, as the calipers are at the front of the IRS, not the rear.