S Type Jaguar Rear Brakes

[shorn]

Because I seem to have few problems working on my Austin Healey, I thought changing the disk pads on my 2000 S Type Jag wouldn't present any problems. Ok, I am just trying to save a buck because the the Jag dealer charges an arm and a leg for everything, and I don't have many limbs left.
Anyway, the fronts were a snap. Just remove two bolts, pull off the caliper, open the bleed screw and push in the pistons, pop in the new pads, replace the caliper, bleed the system and your done. No difficulties.
The rear pads, however, seem to present a little more challenge. I can not push in the pistons. The auto parts store sold me a universal tool to hook up to a 3/8 driver, and said to push and turn on the piston at the same time with the bleed screw open. Truthfully, the universal tool doesn't fit very well, but the piston does not move. Besides, the piston needs to fit in it's present position, not turned clockwise or counter to fit over a little tip on the bottom back side of the brake pad. Bottom line is that I can't figure out how to push in the piston so that the caliper will fit over the new pads. Suggestions /ubbthreads/images/graemlins/confused.gif /ubbthreads/images/graemlins/confused.gif

 

[Keoke]

Shorn, the people at the auto store advised you correctly,can't vouch for the quality of their tool. However, are you sure that the bleed screw is not blocked?---Keoke

 

[shorn]

Keoke,
I get some brake fluid out of the bleed screw when attempting to push in on the piston, just not much as the piston really is not moving. I am going to look for a better tool at NAPA today that fits better. Although I have the emergency brake released, do I need to remove the cable from the caliper and do anything that might release pressure that it may be exerting on the piston? Heck, I thought this Jag was a Ford anyway and shouldn't present a problem.
Thanks for your help.

 

[Keoke]

NAPA May have a good tool, but I got mine from Snap-On fortunately not from China. /ubbthreads/images/graemlins/laugh.gif-Keoke

 

[Throg]

Just had my rear brakes done along with two new tyres. I asked the Jaguar dealer to balance the two front tyres as well and he charged me £50 for the pleasure. Surely this isn't right , no wonder Browns Lane is closing.

 

[John S Farrington]

I am not familiar with the specific rear brake configuration of the S type. On most applications, I can take a wood clamp or similar worm gear device and press the brake caliper pistons into the bores to make room for the new brake pads. There also are tools to accomplish this but a simple clamp works great. I usually dont have to open the bleed port on the caliper since the fluid will also exhaust into the master cylinder/reservoir for the clearence to be made. Hope this helps.

 

[90 XJ-S]

[ QUOTE ]
I usually dont have to open the bleed port on the caliper since the fluid will also exhaust into the master cylinder/reservoir for the clearence to be made.

[/ QUOTE ]

/ubbthreads/images/graemlins/iagree.gif I agree wholeheartedly with Jack and have had great luck, over the years, with the technique described.

However, there are those who worry about the oxidized, hydrolyzed brake fluid in the caliper bodies getting back into the M/C and the rest of the system. They contend that by opening the bleed valve as you compress the pistons will purge these contaminated fluids out.

Good point, and unquestionably true, but if I felt that strongly, I would purge the entire system and refill, rather than some halfway measure.
/ubbthreads/images/graemlins/driving.gif
Mike

 

[trrdster2000]

shorn, sounds like the "S" type has the same setup as the old 280Z on the rear. The piston screwed out as the brakes were worn, so the tool was made to undo the screw or either screw the piston back down the shaft. Good luck, Wayne

 

[jagdoctor]

what you have to do is put the tool on the piston. get an extension and an ratchet. push really really hard on the piston and turn the ratchet. it goes slow but it works. or use a C-clamp and channel locks to turn the piston and the C-clamp to push in.

 

[bigal]

Is it necessary to continue to rotate the caliper piston as it is retracted into the caliper or is a single 90 degree turn required followed by a c-clamp or similar device to force the piston to retract?

 

[Louie]

Just to be sure, I'd check the repair manual -ROM-. Might be an unusual procedure! Is there anything usual about a Jaguar?

 

[maynard]

I don't know where you bought the tool, but if it is the little cube shaped tool it was a waste of money. Most auto parts chains (like Autozone, Murray's) will lend you the proper tool. It usually comes in a case with several adapters, and works well.

BTW, it is always a good idea to clamp the line and open the bleeder before retracting the piston. It does a couple of things.

1. The most contaminated fluid is in caliper (or in drum brakes, the wheel cylinder) since the moisture migrates down. Opening the bleeder gets rid of this.

2. With ABS, contaminates (including moisture) can be forced into the ABS components when the piston is compressed without the bleeder open.