[xj-s] Brake pads, rear, change

(S Bennett) #1

Hello again,

This forum is a great resource for the step by step method of
anything on the XJS.

I am ready to change the pads on my rear brakes. I have completely
flushed the brake fluid. I used the Castrol GT LMX dot4 fluid;
used about � of a gallon. I hope that is the proper fluid.

Just looking at the calipers, it appears a simple procedure, but
since this is an XJS, there must be some tricks.

So�…how do you change the rear pads on inboard brakes?

What is the best way to push the pistons back?

What are the potential �gotchas�?

Thanks for the help.

Scott B
�92 XJS conv–
S Bennett
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

// please trim quoted text to context only

(Nigel) #2

Behalf Of S Bennett

Just looking at the calipers, it appears a simple procedure, but
since this is an XJS, there must be some tricks.

Like you said Scott, its a simple procedure

So�…how do you change the rear pads on inboard brakes?

Remove the spring clips, pull out the pins, and with a pair of pliers or
similar, pull out the pads

What is the best way to push the pistons back?

Gently, I use a thin piece of timber to lever the pistons back into the
caliper

What are the potential �gotchas�?

Generally accepted that the bleed nipple should be opened when pushing the
pistons back, avoids any crud being pushed back into the valve block. This
is not mentioned in the workshop manual, but Jaguar did issue a TSB stating
this.

Nigel
XJS 4 Litre 1993 Ragtop
Manchester
UK

// please trim quoted text to context onlySent: 29 July 2004 19:01

(John-in-CT) #3

In reply to a message from Nigel sent Fri 30 Jul 2004:

I’d add clamping the brake hose when pushing the pistons in to
definitely expel the crud.–
John - '90 Majestic, '95 XJ-S 6.0 Conv., '86 Volvo 760T-R
Stamford, CT, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

// please trim quoted text to context only

(francois panzieri) #4

Doing my xj6 rear pads soon, glad I found this, thanks for the tips!!

(Foggyoo) #5

Do one pad at a time, or piston pops out

(francois panzieri) #6

That brings up a question, bear with me, just thinking outside the box as i m trying to not having to remove the whole rear caliper but i do have a piston that needs changed or at least sanded down. Could I pop it out like that on purpose then put it back in or not enough access or room to do that?

(Foggyoo) #7

Very little room to get it back in,may have to split the caliper

(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #8

Don’t do that. These are brakes. Not the place for shortcuts.

Remember that the seals are not installed on the pistons; they are installed in the cylinder, and the piston slides within it. And what often happens is the piston, which is chrome-plated steel, rusts a bit and the plating flakes off and jams the piston in the seal. There is no plausible fix short of replacing that piston.

I personally chose to go with stainless steel pistons so I’d never have to worry about that plating flaking issue again. Thing is, though, the sealing surface of the pistons has to be polished smooth so as not to wear away the seals. The pistons I got, from a horrible vendor, were not polished. So I polished them myself prior to installation.

(francois panzieri) #9

Makes sense, thanks. Any source this community used to get rebuilt calipers with those stainless steel pistons?
I was able to force my way into removing the completely worn out pad and push seized piston back in to insert a new pad. Very temporary fix, I know but it’ll buy me time until I decided how deep i want to go in this project.

(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #10

I dunno where to buy SS pistons any more since that vendor deservedly went belly-up. Obviously, I dunno any rebuilder that uses SS pistons. I might point out, though, that it’d be pretty easy to make SS pistons – or pay some machinist to make them for you. Remember the OD needs to be polished.

(francois panzieri) #11

I cant find them SS pistons either, I see kits are available for earlier years but not for my 85. I’ll just buy a rebuilt caliper and hope for the best :slight_smile: In the mean time i also need to replace my master cylinder, I have one coming… Are there any precautions i need to take to do it properly? Thanks!

(AndyB) #12

This guy will ship worldwide & these are stainless:

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F311891357702

I’ve no affiliation with the seller other than as a previous customer with 8 of these pistons in my front callipers.

HTH

Andy.

1 Like
(francois panzieri) #13

Thanks! That listing was for front pistons but i emailed him about the back ones. I’ll let you all know.

#14

Rear stainless pistons.I believe they have 2 other brands as well.

(chris gruchawka 1988 XJ-SC) #15

As per Kirby suggestion, buffed them out, they now feel noticeable smoother, no more roughness when you drag your nail over them. Maybe it will prolong life of seal. Takes 10 minutes top, and hot fingers.


brake-caliper-pistons.pdf (599.5 KB)

2 Likes
(Greg) #16

I just replaced rear inboard brake pads for the first time, and it wasn’t too bad…

EXCEPT trying to get those little clips into the caliper pins!!! I ended up having to use my endoscope camera to line up the hole, and then carefully felt for it with the clip. Very frustrating. But did it.