OK. I know that I should nor have done it but it happened. I was changing the rear brakes on my 1990 XJS V12. I removed the old brakes and using the right tool I pushed the pistons back.



now comes the bad part. Before putting in the brake pads I wanted to check the convertible roof operation. Bad news since the pistons have now pushed in and are against the disks. Soooooo what now? Do I need to remove the calipers and then push back the pistons? I also see that the seals are pretty cracked or missing some rubber. Do I need to send them out for a rebuild?


I am lost in the wilderness.

 

OOPS.

Once the pistons have come that far out, the chances of getting them back without damaging the internal o/ring seal are slim, but it is worth a try VERY CAREFULLY, you can do NO more damage.

The outer dust boots all cracked up is also normal, and they can be replaced in-situ if you are patient.

 

I decided to remove and rebuild the calipers and add new disks while I am at it. I am hesitant to pull the whole rear end because I cannot find a video (preferred) or detailed instructions. Everything I have found is after the rear is dropped. So I will do it without dropping the rear.

 

Hi MIFoodie

Any chance of doing a write up on that with some Photos, as I will be doing exactly the same thing myself

 

That is my plan since I can't find any pics or video.

 

The beginning of the rear brakes, caliper rebuild and disk replacement in the car.


Remove axle under tray and do a bit of cleaning. The axle under tray will tell whether the rear end has leaked a lot.


More to come if there is interest.

 

Great Work!

Please keep the Pics coming

 

I would've bet you could have just cracked the bleed valve and pushed the pistons back in. The part that gets pitted, dirty, and or otherwise corroded is the portion that isn't used and is outside the caliper, so working the inside part that is perfectly clean against the seals shouldn't really be an issue.

 

I tried that and it did not work so I decided to pull the calipers and rebuild them since the rubber seems to be quite destroyed by age. I can also then replace the rotors. A lot of work but worth the time.

 

I am VERY interested in your method for doing all of this work with out pulling the IRS... I am so so so VERY interested. Like,,, how did you even get those pictures?

 

I will update with more pictures as the time goes by. I have a daily driver (E55) that needs brakes so the XJS may be slow coming. I have however done a partial cleaning on the rear and so far disconnected the brake lines and emptied them of fluid. To be honest, they emptied themselves and I just placed a glass underneath to catch the fluid so it did not end up all over the garage floor.

 

I got the pictures with my android phone. The car is about 24 inches off of the ground. I needed to get an extension for my jack to do this and slowly jack up the front then the rear then the front, etc.


I now have got the brake lines removed from the calipers and am trying to find the handbrake adjustment screws so that I can start to remove the handbrake mechanism.


More to come.

 

I am very FRUSTRATED with the lack of progress on this project. I loosened the two nuts on the hand brake adjustment and even removed the spring on the passenger side arm. Then I used a winch to pull the two parts on the mechanism together but I still have no slack in the handbrake. Just FYI, the hand brake lever has no resistance.

Any ideas on what to do next to remove the hand brake assembly and cable end? Should I just try to take the hand brake assembly off of the calipers?

 

HELP, HELP, HELP. I am almost convinced to drop the IRS but in any case I need to remove the handbrake cable. How can I do that?

 

This is a really good write up already if you are interested.

 

Replacing Rear Calipers W/O Dropping I.R.S.

 

Hi MIFoodie

A couple of suggestions that 'may or may not Help' bearing in mind that I have also never done this before but in you very first set of Photos, the one Top right shows a Spring with a Hook that is holding the Forks open and pulling on the Cable in order to keep it tight

So if you haven't already done so, it does look like this 'Tension Spring' does have to come off, which 'Should' give you some slack in the Cable, so you won't need to use a Winch, as I believe you said you tried doing

Once that Spring has been detached you should be on a 'Home Run' because without any Tension no longer in the Cable, you should be able to grip the end of the Cable (by the nobbly bit on the end) and then pull it back and just lift it out of the slot

Just throwing that out in Case you hadn't done it and as I say I've not done this myself, so its the blind leading the blind at the moment

Then there is Plan: 'B' which I think would be my Favoured Option, which I have done myself before so you can follow my Pics to see what I did, although my reason for doing it wasn't quite the same as yours

Where Plan 'B' would be a quick fix, as long as your Rear Brake Calipers are no worse than mine and they are NOT LEAKING

OK so here we go:

(1) Undo the Bleed Nipples on Both Calipers

(2) Get something like a Thin Paint Scraper, with a Blade about One Inch Wide

(3) Slide and Jiggle the Thin Paint Scraper, underneath the Pistons of the Calipers and then ease them back into there Sockets, so that you can then renew the Brake Pads

I also ground about half a mill off the Metal of the Brake Pads so they would slide in easy and wouldn't get jammed in the Calipers

Then after a bit of a Clean Up, 'Cherry' was back in the Game

Your Car, Your Call, just trying to be helpful and save you some work, since it seems you may have hit a Brick Wall where progress is Slow, if I remember correctly 'Sidescrollin' came out with a Similar Suggestion

Here is how I did it and here are all the Pics you are going to need

On Page: 25 of my 'Cherry Blossom' restoration thread and here is a link to that Page: Replacing the Rear Brake Pads on my 1990 XJS V12

 

OK. So now I have decided to drop the iRS, and did that successfully. It was much easier than working overhead for long hours.

 

Extremely sensible of you. Do it all easily and all good. Then reassure OB how straightforward Dropping the cage actually is!

 

I'm all for dropping the cage for anything other than pad replacement. As long as the radius arm bushed come off that is.