Hi to all,
This is for a 1989 XJS HE with a Salisbury diff. and inboard rear brakes.
I really need help, I am in the process of fitting new rear rotors and calipers to the rear of this car, following what most people have written in the forum I decided to remove the cage from the car, not difficult after all... Removed the LH caliper and rotor, and besides being uncomfortable to work on, it was easy for me... The problem I am having is with the RH caliper, actually with the lower of the two bolts that hold the caliper to the bracket, I was able to unscrew it and I know I will not be able to remove it and that it has to come out with the caliper, the problem is it won't let me pull the caliper out, it touches both the diff cage and the caliper bracket at the same time while trying to pull it out... I have been fiddling for almost 2 weeks and I really cant go any further... I have loosen the rotor and didn't help at all... This is driving me crazy, any ideas or tricks to pull the RH caliper?

 

Hi alpecsa

Since you've disconnected the Brake Pipe that leads to the Master Cylinder Actuator

You need to unscrew the Bleed Nipple and push the Caliper Piston back in, as that appears to be the only thing that is preventing the Caliper and its bolt from sliding out and also the Handbrake Pads may need to be removed

Also you may have to re-tighten the Rotor (just a little bit) as undoing it before hand would give you even less space than you have got now

After that then it should slide out easy

Note: To those who've never done this, never compress the Brake Caliper without opening the Bleed Nipple First, as forcing Brake Fluid the wrong way back up the System can very easily damage the Master Cylinder Actuator with microscopic pieces of crud, that could also block the valves! (This is one of the 'Golden Rules' of owning an XJS that should never be broken)

 

OB,
Thanks so much for your reply, the reason for doing the rear brakes is that the RH caliper is frozen and the rotor got scored, so you are correct, the caliper piston not being fully retracted might be the culprit for the caliper not coming out, this is the reason why I loosened the rotor trying to get some more movement, but will try to push the piston back in... Handbrake mechanism has been removed already
Alfredo

 

Hi Alfredo

Worst Case Scenario, you will have to cut the Bolt but seeing how the Piston is Stuck then I think that it would pay you to refurbish both the Calipers which is not that difficult once you get the hang of it and also replace the Brake Pads as well the Handbrake Pads

Together with a New Rear Brake Hose, which is easy to do with the Cage out but a Nightmare to do when its not

How to rebuild the Rear Calipers (How hard can it be!)

 

OB,
Thank so much for your advice, last night I tried to push in the pistons with no luck, they are really stuck... But looking closer, the pistons don't seem to be interfering, at least that is what I can see. The reason for me to loosen the rotor was precisely because I thought the pistons were touching the rotos, but they are not. I already have new (refurbished) calipers, new rotors, pads, ebrake pads and hoses... Cutting the bolt would let me remove the caliper, but I will need a new bolt that will not go in, do you know what I mean?
This car is in really good condition and has about 40K miles, it has not been abused and it is very original, but one really never knows who has been messing with it.
My next move will be to split the caliper and see if I can take the caliper out one half at a time... I really don't know what is going on, could it be the calipers mounting bracket that was installed in a wrong position? Did some one use a longer bolt and put every thing together with the diff out of the cage?...
I am really going crazy... I will continue next Monday and will try to enjoy the holidays.
Merry Christmas and happy holidays to all...
Alfredo

 

Can you rotate the caliper around the circumference of the brake disc and take it out from the rear rather than the front of the cage? The factory manual mentions doing it that way.

 

No, I can not, the lower bolt prevents from doing that, if I try to rotate the cliper around, the lower bolt (the only one of tje two still in situ) will hit the diff and the caliper bracket, preventing it to move any further... Take a look at tje first picture I sent, I don't know if it is clear to other than me...

 

You need to take off the big tie plate under the differential with the 12 or so bolts that hold it on. That should have been step 1. That should give you the room you need.

 

Good point, will do that next monday... I thought it was only needed if doing the calipers with the cage on the car, but apparently not...
Thanks for your advice

 

Hi Alpecsa

Maybe the previous Owner or the Owners Shop used the wrong Bolt when they put that Caliper on, where in order to get it in they may have removed or backed off the Drive Shaft

It 'could' be that they messed up the Thread on the Caliper Bolt by Over Tightening and as they hadn't got the right Bolt, replaced it with the nearest one they could find (that was a bit longer)

In any event have a look at my Thread on Refurbing the IRS as you may be able to take something from it that may help you

My A to Z Guide on Removing and Refurbishing the IRS Cage on a Jaguar XJS

Everything you need to know as well as lots of stuff you probably don't!

Removing The IRS Cage

Refurbishing the IRS with New Rotors and New Calipers

Making 'Hopefully' Indestructible Hand Brake Pads

Rebuilding the Calipers

Cleaning/Painting and Replacing the Cage under the Car

Above all there are lots and lots of Photos of every part of the process

What could possibly go wrong!

Removing and Rebuilding the IRS Cage on an XJS including Loads of Photos

 

OB,
Thanks so much, will go through your post on removing the cage... I'm sure it has to be something simple, once I find it...

 

Qlpecsqm
If you have to find a new bolt, having cut the old one, be VERY careful to get the correct thread.
https://parts.jaguarlandroverclassic...e=900582913734

They are still available from Jaguar. And Manners etc
https://www.jagspares.co.uk/product/...-e-type/c30251

And even when you have it, test it in the diff threaded hole before mounting the caliper.

 

Greg,
Thanks for the links, will keep them as a last resort, I would like to find out what is going on...
I went to the garage this morning and kept thinking of what you all have commented, even I can see the manual calls for removing the "tie plate", I can't see how that would help because when bringing the caliper to the lower position it touches the wishbone before even getting low enough for the the plate to be an issue... But I will be taking the plate off any way since I really don't know what is going on, so I better follow the advices I'm getting.

 

Ok, here I go again... I have not been able to pull the caliper out, the next step will be to disassemble the whole cage and try to get better access. This is something I would like to avoid mainly because I can't understand what the issue is, I mean, some people even change the calipers without droping the cage, so what is going on?
I have notice the following, when I first started pulling the calipers, I notice that on the RH caliper, the one I am not being able to pull out, the 2 bolts that hold the parking brake where very difficult to acces, to the point that I had to use and open wrench and not a socket as I did on the LH caliper, see attached pictures.



As you can see in the pics, the RH caliper is about 1/2" (12 mm) higher than the LH in relation to the cage. Looking at other pics and videos on the web, I can tell this is not normal and should be symmetrical, so what could be causing this? It is clear some one has done some work before just by looking at the "safety wire" that I haven't replaced.
So, before I start taking the cage from the diff assembly, has any one seen this issue before? Any idea
why the diff might be tilted to one side?
Btw, I can not see any damage on the cage...
I hope this makes sense...
Alfredo

 

The first pic was taken before removing the parking brake from either of the 2 calipers

 

Hi Alpecsa

Maybe You have got a Broken Spring?

Though now you've got the Cage out, please try and talk yourself out of Removing that Bottom Plate (at least for now)

Firstly because you don't need to, so why make work for yourself

Although much more important is, there is a real and present danger of Breaking one or more of those little Bolts

As these could be very hard to undo, if a Shop has ever put a Jack under that Plate to change a Wheel, because this could cause the Plate to deform, making removing those Tiny little bolts an accident waiting to happen and so if one of those bolts decides to snap off in the hole, then you will be left with an almost impossible Mountain to Climb

Even worse or just as bad if during maneuvers, should one of those Drive Shafts decides to drop down and hit the edge of the Plate, the weight of the Drive Shaft, could strip the threads of one or more of those Bolts

So although this may go against some of the advice that you have been given, I have done this both ways and know the risks involved so taking off that bottom plate is really now a pair of dice I wouldn't want to roll if I were you

Best to lift the Shroud off the Cage and then go from there

 

Are you sure you are removing the caliper from the adapter bracket, rather than the adapter bracket from the diff? The adapter bracket on the side of the diff stays in place, and you remove the caliper from it.

 

Even experienced XJS owners have had some problems in removing that RH caliper ona Salisbury diff. The general consensus seems to be to remove the pads, undo the bolt just sufficiently to clear the mount bracket, wiggle the caliper and bolt such that it can just clear the diff then slide it over the top to the back and then round to the bottom when it then be withdrawn from the bottom after the tie plate is removed. The trick seems to be getting that bolt to just miss the diff,

Good luck

Paul

 

I did this last summer myself when replacing the output shaft bearings and seals. That bolt appears to be out, I remember it was close. As suggested snug the rotor backup. I don't recall but I may have removed the cross over line and I had no exhaust pipe in the way. The caliper should slide forward, you may have pry a little to a point it loosens enough to rotate up and pull the bottom out first. Once the calipers were out I loosened the axles first taking note of the shims and by marking a stud to flange for reassembly. To remove the rotors I removed 1 shock on each side then slid out the shock rods. I used a chain and eye bolts to lift the cage with a cherry picker. The bottom tie plate had to be loosened quite a bit to allow the wishbones to hang almost vertical before the rotors would slide off. Be careful not to lose or mix the shims behind each rotor.

 

Thanks to all that have shared different solutions to this problem, I uploded 3 videos on YouTube (don't know why one came up as a "shart") that I think will make things easier to understand. The videos were taken on my phone and the lights were awful, but I think you'll see what I am trying to show. Also, as you can tell, English is not my first language, so I hope you can understand what I am saying



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