It's not very special but it does make the job easy and safe, whereas you can easily slip with something improvised and wreck the caliper. I bought a generic tool (no loaners in UK) for about $20 that'll do dozens of styles of calipers.

 

Update:

Since my new rear brake pads are due to be delivered in this afternoon's mail, I picked up the loaner kit from Advance Auto Parts this morning, turned off the EPB, jacked up the rear wheels, pulled the rear calipers, and located the appropriate disk in the kit to spin-and-push both pistons back into their housings. You do indeed turn the kit tool clockwise. At first, neither piston wanted to budge. After leveraging myself properly so I could lean downwards on the caliper, applying some heavy inward force with my tool-twisting hand, and spewing out the appropriate cursewords, both pistons released and began to spin inwards. I cranked them down to within about a quarter-inch of being flush in their housings....

Now I just need to wait for today's mail delivery so I can install the new rear brake pads and put everything back together. I was expecting caliper pins that the rear pads would slide on just like the front pads do. But that's not how these rear brakes are designed. No caliper pins to lubricate, just some general component cleaning to do with a spray can of brake cleaner....

It's a messy job so have some old rags to wipe your hands with as you work and some Lava or Goop handy to wash up with after you've finished the removal part of the job. As usual, my hands and forearms were filthy. Always seems to be that way after any brake job I do regardless of the vehicle. Putting everything back together shouldn't be quite as messy. We'll see....

 

The caliper must still be free to slide laterally in order to apply the outer pad similar to the fronts, so the pins should be removed for lubrication.

 

Where are the rear caliper pins and how do I remove them? I see no mention of this in my JTIS CD info....

 

Since 'upgrading' to Windows 10, I can no longer get JTIS to run. Not sure I have the patience to reinstall it with the work around (yet again).

I believe there was an excellent write up done by Gus specifically for the rear pads/caliper. It shows the pins in very clear detail.

 

Thanks for the tip to check out Gus' site (JagRepair.com - Jaguar Repair Information Resource). I did, and Gus indeed has several very detailed photos showing exactly how to remove the four rear caliper sliding pins. All four of my pins pulled out by hand with almost no effort on my part. Their rubber accordian sleeves are all still in good shape and therefore still retaining their interior lube grease. I did not have to add any additional grease at all....

Yet another example of why this forum is more valuable than JTIS. JTIS is indeed a good tool, but this forum is by far the best tool any of us have in our toolbox....

Thanks again. I hope to finish this job when the mailman gets here with my new rear pads. It will probably be close to 95 degrees outside when he does. I'll be sweating so much it will be difficult to see through the sweat pouring off my forehead into my eyes....

 

Update:

My new rear brake pads were delivered this afternoon and I had them installed within 30 minutes. I guessed quite closely on how far to wind the pistons back into their housings and only had to pump the brake pedal about three times to get it back to normal. Put the rear wheels back on, lowered the rear end back onto the ground, tightened up the rear lug nuts, then cleaned up my hands and arms. Reset my EPB with no issues, then took the car out for a six-mile test drive to seat the new rear pads and ensure that everything was normal. I'll return the loaner kit tomorrow morning for a full refund of my deposit....

Thanks again to all who contributed advice in this thread. This would not be a bad job in 20-degree weather but I don't want to do it again when it is in the 90s outside....

 

How were your EPB pads?

I finally replaced mine at 98K miles. Not that easy to find them outside of Jaguar!
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It's not an STR, and doesn't have Brembos, so doesn't have separate EPB pads.

 

Correct. The EPB is connected to the regular rear brake pads so it is all one system. That's why these rear brake pads must be spun-and-pushed back into their housings using the brake caliper loaner kit. This was the first time I've done it myself so I had a bit of a learning curve....

 

"Because the 'just enough' process doesn't avoid the problem unless you're exceptionally lucky. You'd have to assemble/take apart/assemble/take apart an unknown number of times gradually turning the piston until the pads are just far enough to slip over the caliper. It's possible/probable at that point that they would be just half a hair too far apart and the problem outlined above with the EPB actuator being over extended would occur.

The chances of getting it right are the same as having a firm high foot pedal right away with no pumping required.

Much easier doing it the OEM way which also guarantees success the first time"

Mikey,

To eliminate the trial and error method of retracting the pistons, and not go too far, I measured the thickness of the new pads and rotor and then retracted the piston until I had the same gap between the piston and outside (fixed) caliper frame . Quite easy to get it right on the first try and not go too far.

Tailwinds

 

Sorry you are correct!
I have STR on the brain. Please disregard.
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The 'not going too far' idea is being grossly misunderstood.

It can ONLY pose a problem if the EPB is actuated before the pads are pumped via the foot pedal into the normal service position. In Jon89's case it took him three pumps of the pedal to achieve this. Had he activated the EPB first, there would have been a good chance of having the same problem as Cambo.

I estimate that having to pump the pedal more than one or two full strokes after installing new pads could induce the problem. Spending time trying to calculate and adjust to this precise setting is wasted time and effort- the pedal still needs to be pumped to establish normal clearances.

It's the sequence of steps in the process that are important, not avoiding winding the piston too far back.

 

I replaced my pads and rotors on the rear for the first time. I fought with the c-clamp until I read through all of this thread. Using the loaner tool from Advance Auto Parts and cracking the bleeder got the pistons all of the way back in. I could see that using one of those cubes and a ratchet would be very difficult. After I was all done I pumped the brakes a few times before and after starting the car and there was no squishy brake pedal, so I did not bleed the brakes even though fluid was lost during the pushing of the pistons back. I also did not reset the electric parking brake at that time since I got no warning indicator. I went for a short drive around our hilly neighborhood and it seemed that the brakes were applying themselves. I took it apart again to push the pistons back completely this time. I drove again and seemed fine in the neighborhood. Again, I did not bleed or reset the parking brake. A couple hours later I drove a mile or so to the grocery store and the brakes were applying themselves again. The rotors were very hot to the touch. After I let them cool for a while, I went through the procedure to reset the parking brake, but each time it beeped on the last step, releasing the parking brake. My theory is that either I should have bled the bakes regardless of the absence of a squishy pedal or I should have reset the electric parking brake before driving. What did I do wrong? What will I need to re-do?

 

Definitely do the EPB, no matter what.

 

My $0.02....I have a brake caliper kit that has the correct die for the ATE brake calipers ( same as VW and Audi ). AutoZone will rent you one. I have done several rear brake replacements on S-Types and I have always screwed the pistons in most of the way with the bleed screw open. It gets rid of the old fluid in the caliper and speeds up the brake fluid flush I add when the pads get replaced. I just start the car and pump the brakes until the pedal is firm and then the last step is to go through the EPB calibration procedure.
I usually replace the caliper slide pins and bushes on rear brake jobs, they are inexpensive. I grease them with Permatex synthetic brake grease.
Also.....
Shut off the car with the EPB off. Pull the EPB fuse. Saves having the EPB engage when you don't want it to and you don't have to disconnect the battery to reset the EPB module to initiate the calibration procedure.

 

Go through the EPB calibration and then jack up the rear under the diff so both rear wheels are clear of the ground. Apply the EPB and verify both wheels are locked and then release the EPB and verify both wheels are free. If one wheel is still locked or dragging remove that wheel and take a look at the EPB cable where it connects to the caliper arm. If the cable end is loose the on the arm and the arm is not against the stop pin then the caliper pivot arm is binding in the caliper or the cam that has the return spring is binding on the post. If the cable is tight on the EPB arm then there is probably an issue with the cable, controller or motor. I looked at a friends car with the same problem a couple of month ago and it was the pivot arm binding in the caliper. I had to replace both rear calipers. He chose to use new calipers, but there are rebuilt units available.

 

The hydraulic system is sealed and is under pressure when pressing the brake pedal. Trying to push the caliper piston back in is like trying to press the brake pedal just using your fingers on a sealed system

The amount of brake fluid content will be slightly higher as you've topped up the fluid level and as the pad thickness reduces with wear. So the piston sits further out towards the disc.

If you want to push that piston back you need to release the pressure of the brake fluid because it has nowhere to go in a sealed system. Unscrewing the bleed nipple is one way and I'm glad that someone pointed that out to you. There is risk of letting air into the system if you don't nip the bleed valve up quickly.

The other way to relieve the fluid pressure when pushing the cylinder back is to remove the filler cap on the brake fluid reservoir. However this carries the risk of brake fluid overflowing out of the filler cap and into the engine bay with potential major damage to paintwork and components.

To avoid this potential problem I cable tie some old absorbent cloth all the way around the body of the brake fluid reservoir body as a back up.
But by simple observation of the fluid level in the reservoir as you push the piston back in or getting someone else to watch it, then you can avoid spillage.

You need to drain the excess fluid in the reservoir once the new pads or new pads and discs are in place and its all bolted back up. To drain the excess which I do maybe 2 or 3 times while pushing the piston back is to use a plastic syringe which is only used for brake fluid (Avoid cross contamination of other fluids). You can buy these plastic syringes off eBay just for this job. But I either keep an eye on the brake fluid level myself or get a friend to do it for me.
So that's another way of doing it.

I don't know about anyone else but I clean up the brake caliper and general area as best I can just so its a proper job.

I've just bought a whole new rear LH caliper for mine to be fitted on Weds.

 

Sorry but this is misleading. If the foot brake pedal is released there is only minimal resistance to the flow of fluid returning to the reservoir. The system is not 'sealed' in the manner you have inferred. If it was, the fluid also would not flow to the calipers to accommodate pad wear.

There is a diaphragm in the master cylinder to segregate the fluid from the atmosphere. The prevents air contamination of the fluid. There is no need to loosen or remove master cylinder caps on modern cars.

Some owners choose to open the bleeders during pad renewal to make piston retraction easier and to remove old fluid from the caliper. That's fine, but the same volume of fresh fluid must be added to the master cylinder reservoir before the car is returned to service.

It appears that the OP has not replaced this lost fluid.

It also appears that the OP might have damaged the caliper by trying to force the pistons back by using a C-clamp.

I'd replace A) the missing fluid B) calibrate the EPB as a first step. If the problem persists, I'd verify the EPB function as Geezer suggests.

 

The hydraulic braking system is sealed otherwise it wouldn't work.
Pressing the brake pedal pressurises the system which then applies the brakes. That is the very basics of how it works.

To push the caliper piston back requires the bleed bolt to be slackend off or the fluid reservoir cap to be removed.
That is VERY VERY BASIC stuff nothing to do with "modern cars" or whatever that means.
Done it many times that way.
The S type was made by Ford, it works the same as a Ford rear caliper and hydraulic brake. They are very simple calipers nothing special.