[xj] Replacing Rear Disc Brakes, Calipers, Rotor (XJ6)

XJ
1

Any suggestions on where to begin the job of replacing rear disc
brakes, calipers, and rotor on an 1985 XJ6 Series 3. I have the
manuals but I don’t have a lift to do the job. Although I have
experience repairing cars, we bought this Jag, our first, at the
end of November. In January we discovered the brakes were down to
the bare metal & it also looks like one of the pistons in the
caliper is seized. These brakes are unlike any brake job I’ve ever
done. If it only involved changing the pads, I would have been
driving the car again by now. Any help or advice would be be
greatly appreciated. At this point I have more questions than
confidence. I feel overwhelmed by the job and I’m wondering if
it’s something I should really be doing. Thanks in advance for any
support you can give. Dan–
Judy
Spring City, PA, United States
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2

Any suggestions on where to begin the job of replacing rear disc
brakes, calipers, and rotor on an 1985 XJ6 Series 3. I have the
snip
greatly appreciated. At this point I have more questions than
confidence. I feel overwhelmed by the job and I’m wondering if
it’s something I should really be doing. Thanks in advance for any
support you can give. Dan

Dan, this is definitely one of the more difficult jobs on the XJ cars.
While possible to do on the car, it’s considered to be simpler to just
drop the entire rear cage and do the work on the bench. Look in the
FAQs under the Rear Suspension heading for information on dropping and
rebuilding the rear subframe. That should give you a bit more info to
decide if you want to tackle it yourself. You’ll need some tall
jackstands, a good trolley jack, etc.

Also, take a look through the archives, and you’ll find plenty more
information about it.

Learn all you can from the people here, as in my mind, starting a job
feeling overwhelmed is a sure recipe for disaster.===================================================
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3

In reply to a message from Judy sent Tue 10 Feb 2004:

If you have about 3,000 bucks to have it done by a shop,
by all means have it done. If you have time and don’t
need the car that bad, the job can be done by you if
you’re mechanically inclined. Its not that hard to do.
You need a good floor jack, 4 good jackstands to set the
car on. Some pointers I can give you here, it envolves
disconnecting the handbrake cable in the rear, then
disconnecting the rear brake line, disconnecting the
shock absorbers, disconnecting the rear exhaust cross-
over pipes, disconnecting the rear proppeller shaft.
Then the whole cage can be put on the floor jack and
dropped down after taking mounting nuts off.
Simple isn’t.
Let me know if I can help.
Walter–
The original message included these comments:

Any suggestions on where to begin the job of replacing rear disc
brakes, calipers, and rotor on an 1985 XJ6 Series 3. I have the
manuals but I don’t have a lift to do the job. Although I have
experience repairing cars, we bought this Jag, our first, at the
end of November. In January we discovered the brakes were down to

–
69E/78XJ6
albuquerque/new mexico, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

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The archives and FAQ will answer many queries on the XJ series…
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4

G’day,

I have done the job without removing the entire suspension cage, but it is a
fiddly job lying on your back. You’ll need a couple of sturdy jackstands to
support the car.

A brief description of what to do follows.
1. Support the car safely, high enough so you can lie on a garage
creeper and move around underneath it.
2. Get a lead light under there so you can see what you are doing.
3. Get a small mirror, one mounted on a magnetic base with a flexible
shaft is best.
4. Disconnect the handbrake cable and remove the handbrake calipers,
they are mounted on to the main brake calipers. There is a locking tab that
needs to be released first. The h/b calipers, once unbolted can be slid
rearwards around the disc and removed through the rear opening in the IRS
cage. You don’t need to reomove the tieplate.
5. Clamp the flexible brake hose so the fluid wont leak out.
6. Remove the fixed brake pipes between the calipers and the ‘T’ union.
7. If the calipers have been worked on the is a good chance that the
safety wire wont have been replaced, if it is still there, cut it and get
rid of it.
8. Use a ring spanner to loosen the two caliper bolts, you wont be able
to completely remove them until the caliper can be moved away from the final
drive, and remove the calipers. Same goes when reassembling, you have to
insert the bolts into the holes in the calipers before you position them
against the final drive.
9. With the road wheels removed, and using a socket and a long extension
undo the four disc retaining nuts. Take note of number and position of
spacers used between the disc and the drive shaft and also between the disc
and the final drive output shaft. They are a different type of spacer so you
can’t mix them up, just don’t lose any.

Now you have all the bits removed you can overhaul/replace the calipers and
discs and as they say in the repair manual “assembly is the reverse of the
above”. Oh and don’t forget to overhaul the handbrake calipers while you
have them off.

It’s tedious and at times a real PITA but it’s do-able, of course if you
have any other work to do on the rear suspension unit such as bearing or
seals etc it would probably be easier to drop the whole cage and work on it
out of the car.

Hope this helps and if you need any more tips mail me.

Regards,
Jeff Watson.
(IRS Master Tech) :^)> The original message included these comments:

Any suggestions on where to begin the job of replacing rear disc
brakes, calipers, and rotor on an 1985 XJ6 Series 3. I have the
manuals but I don’t have a lift to do the job. Although I have
experience repairing cars, we bought this Jag, our first, at the
end of November. In January we discovered the brakes were down to

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/index.html
Archives: http://www.jag-lovers.org/lists/search.html

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5

Dan,

The independent rear suspension in these cars is a thing of beauty, a very
well engineered component, especially when you consider it was designed
nearly 50 years ago. Everyone who owns one of these cars should have the
opportunity to get to know it better…

But, you really need to assess your abilities to carry out this kind of
work, and your access to the necessary tools. As others have told you, it is
possible to do the brake work without dropping the rear subframe, but I
personally would not be willing to suffer that way. Dropping it out of the
car is not onerous, and it makes the brake work a treat. The biggest
challenges are likely to be separating the mufflers from the overaxle pipes,
and convincing the front radius arm bushes to drop off their mounting
points. Other than that, there are 12 bolts to undo (did I count them
correctly?), one hydraulic brake line to separate, and the handbrake cable
to disconnect. You do need tall sturdy jackstands, and a 3 ton or greater
floor jack. The assembled subframe is very heavy and must be dealt with
accordingly, with great respect.

I am nearly ready to put my completely restored (and yes, Alex, I replaced
just about everything!) rear subframe back in the car, so my experience with
all this is very fresh. If you want any help or suggestions, ask away!

Cheers,

Doug Ingram
Victoria BC Canada
1987 Jaguar XJ6 VdP----- Original Message -----
From: “Judy” ftxt33a@aol.com
To: xj@jag-lovers.org
Sent: Monday, February 09, 2004 5:48 PM
Subject: [xj] Replacing Rear Disc Brakes, Calipers, Rotor (XJ6)

Any suggestions on where to begin the job of replacing rear disc
brakes, calipers, and rotor on an 1985 XJ6 Series 3. I have the
manuals but I don’t have a lift to do the job. Although I have
experience repairing cars, we bought this Jag, our first, at the
end of November. In January we discovered the brakes were down to
the bare metal & it also looks like one of the pistons in the
caliper is seized. These brakes are unlike any brake job I’ve ever
done. If it only involved changing the pads, I would have been
driving the car again by now. Any help or advice would be be
greatly appreciated. At this point I have more questions than
confidence. I feel overwhelmed by the job and I’m wondering if
it’s something I should really be doing. Thanks in advance for any
support you can give. Dan

===================================================
The archives and FAQ will answer many queries on the XJ series…
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6

Great Doug! Now, about the terrible ‘old’ parts you were going to send me.
:]–
Alex
79xj6L SII (BRG + wires)
86xj6 SIII (Black)
61 Sprite MkII (Red)
Menlo Park, Calif.

Doug Ingram wrote:

Dan,

[clip]

I am nearly ready to put my completely restored (and yes, Alex, I replaced
just about everything!) rear subframe back in the car, so my experience with
all this is very fresh. If you want any help or suggestions, ask away!

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/index.html
Archives: http://www.jag-lovers.org/lists/search.html

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7

Hmmm, sorry, I tossed all the bearings - let’s see, I could send you the
subframe mounts, and the flexible brake hose, and how about a pair of
rotors? some old used nylocs? These could all be yours!

Doug----- Original Message -----
From: “Cannara” cannara@attglobal.net
To: “XJ” xj@jag-lovers.org
Sent: Monday, February 09, 2004 10:41 PM
Subject: Re: [xj] Replacing Rear Disc Brakes, Calipers, Rotor (XJ6)

Great Doug! Now, about the terrible ‘old’ parts you were going to send
me.
:]

Alex
79xj6L SII (BRG + wires)
86xj6 SIII (Black)
61 Sprite MkII (Red)
Menlo Park, Calif.

Doug Ingram wrote:

Dan,

[clip]

I am nearly ready to put my completely restored (and yes, Alex, I
replaced

just about everything!) rear subframe back in the car, so my experience
with

all this is very fresh. If you want any help or suggestions, ask away!

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/index.html
Archives: http://www.jag-lovers.org/lists/search.html

To remove yourself from this list, go to
http://www.jag-lovers.org/cgi-bin/majordomo.

// please trim quoted text to context only

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/index.html
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8

In reply to a message from Judy sent Tue 10 Feb 2004:

I’ve done just this job in the last month. Everything said here is
spot on. The only thing I would add is:

Don’t even try to do the job in situ. Drop the cage and do the
brake work on the floor. I started off hoping to do the brakes with
the cage fitted but after shearing just one handbrake capiller
mounting bolt and getting a split lip from dropping a wrench onto
myself, realised that that was the end of the road for that idea.
Dropped the cage, which took an evening, and voila! Sorted easy.
And it does help you to fully appreciate how the rear end all fits
together.

Of course, if your feeling rich, just give it to a garage to do!

Regards

Matthew–
The original message included these comments:

Any suggestions on where to begin the job of replacing rear disc
brakes, calipers, and rotor on an 1985 XJ6 Series 3. I have the
manuals but I don’t have a lift to do the job. Although I have
experience repairing cars, we bought this Jag, our first, at the
end of November. In January we discovered the brakes were down to
the bare metal & it also looks like one of the pistons in the
caliper is seized. These brakes are unlike any brake job I’ve ever
done. If it only involved changing the pads, I would have been
driving the car again by now. Any help or advice would be be
greatly appreciated. At this point I have more questions than
confidence. I feel overwhelmed by the job and I’m wondering if

–
Matthew B(UK)
London, UK, United Kingdom
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/index.html
Archives: http://www.jag-lovers.org/lists/search.html

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9

The independent rear suspension in these cars is a thing of beauty, a very
well engineered component, especially when you consider it was designed
nearly 50 years ago. Everyone who owns one of these cars should have the
opportunity to get to know it better…

I might also suggest that you get a copy of the XK Engine Overhaul book put
out by Kelsey Publishing. Lots of good engine info, of course, but they
also have part of it devoted it to the rear subframe, with plenty of photos.
Having it may help you decide if this is a job you want to tackle or farm it
out.===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/index.html
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10

I’m there Doug, feed me! I thought you were saving those rotten, crumbled old
bearings for me too!–
Alex
79xj6L SII (BRG + wires)
86xj6 SIII (Black)
61 Sprite MkII (Red)
Menlo Park, Calif.

Doug Ingram wrote:

Hmmm, sorry, I tossed all the bearings - let’s see, I could send you the
subframe mounts, and the flexible brake hose, and how about a pair of
rotors? some old used nylocs? These could all be yours!

Doug

----- Original Message -----
From: “Cannara” <@Cannara>
To: “XJ” xj@jag-lovers.org
Sent: Monday, February 09, 2004 10:41 PM
Subject: Re: [xj] Replacing Rear Disc Brakes, Calipers, Rotor (XJ6)

Great Doug! Now, about the terrible ‘old’ parts you were going to send
me.
:]

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/index.html
Archives: http://www.jag-lovers.org/lists/search.html

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11

In reply to a message from Chuck Renner sent Tue 10 Feb 2004:

I’ve worked on rear brakes on a few of these cars now. I very much
agree with those who recommend dropping the sub frame.
I know some mechanics can overhaul brakes in situ. but to do it you
need to know where everything is by feel and touch. Not easy first
time around. Any time saved by not lowering the subframe will be
lost elsewhere.
One point I would add is that it’s usually easier to undo the
radius arm at the wishbone end and leave the joint on the underside
of the car alone. Unless you intend to replace the bushes at the
same time. To do this you will need to undo the lower shock
absorber mount pin.
Then as you lower the IRS on a trolley jack, you will need
to ‘bend’ the radius arm aside at some point to clear the frame.
The bushes are flexible enough to allow this.

Last time I did all this, by far the biggest problem was a totally
corroded brake pipe joint where the flexihose from the subframe
joins the solid pipe under the car. No amount of WD40, heat, and
abuse, would shift it. In the end I’d damaged the pipework.
I had to clamp and cut the flexihose (no great loss), but then also
had to replace the pipe from front to rear. This alone took more
time than lowering the IRS which was otherwise straightforward.
Got Ya!

Regards,

Andy–
Andy Blakey 1983 XJ6 III 4.2 Auto (UK) '‘Jane Seymour’
London, United Kingdom
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

===================================================
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12

Good morning all. Will get down to introducing myself properly the first chance I get, but in the meantime, I thought I’d contribute to the forum a little. I am reviving this topic, because Jeff_Watson’s description is the most accurate description I found to do this job, but I thought I’d insert my comments to clarify and make things easier for anyone attempting this. My latest rear brake job is currently on the trolley behind me as I write this, so the cuts haven’t stopped bleeding yet! Btw, one point, just my ha’penny’s worth, it’s hell on earth to do this job with the IRS in place. TAKE IT OFF THE CAR!

I have copied and pasted the text from the thread above, and inserted my additional comments in italics. So most of the text below isn’t mine-

Having gone through this process a number of times, I would like to add/amplify on this particular comment -

A brief description of what to do follows.

  1. Support the car safely, high enough so you can lie on a garage
    creeper and move around underneath it. NOTE comments further below regarding having to drop the lower swing arm out of the way to remove the disc/rotor, you need to have the IRS at least 2.5 feet off the ground.
  2. Get a lead light under there so you can see what you are doing.
  3. Get a small mirror, one mounted on a magnetic base with a flexible
    shaft is best.
  4. Disconnect the handbrake cable and remove the handbrake calipers,
    they are mounted on to the main brake calipers. There is a locking tab that
    needs to be released first and then start undoing the bolts (7/16AF). (the bolts might be seized in place, so get ready here for some swearing ) The h/b calipers, once unbolted can be slid rearwards around the disc and removed through the rear opening in the IRS cage. You don’t need to remove the tieplate.
  5. Clamp the flexible brake hose so the fluid wont leak out.
  6. Remove the fixed brake pipes between the calipers and the ‘T’ union.
  7. If the calipers have been worked on the is a good chance that the
    safety wire wont have been replaced, if it is still there, cut it and get
    rid of it.
  8. Use a ring spanner to loosen the two caliper bolts, you wont be able
    to completely remove them until the caliper can be moved away from the final
    drive, and remove the calipers. Same goes when reassembling, you have to
    insert the bolts into the holes in the calipers before you position them
    against the final drive.
  9. With the road wheels removed, (remove road wheels before you even start to stop hitting them) and using a socket (11/16AF) and a long extension
    undo the four disc retaining nuts. Take note of number and position of
    spacers used between the disc and the drive shaft and also between the disc
    and the final drive output shaft. They are a different type of spacer so you
    can’t mix them up, just don’t lose any. (NOTE, and this is my main reason for responding to this topic. There is no way that you can remove the brake disc with the lower swing arm in the normal position. You need to remove the shock absorber top bolts, and lower it down fully. It is important to note that the lower swing arm has to be allowed to dangle fully down, otherwise the brake disc/rotor won’t come off!!! Also, the swing arm with the hub attached is approximately 2.5 feet long, so you either need really large axle stands, or otherwise, do what I do, use a two post jack to begin with to lift the vehicle, lower the car onto the trestle/trolley when you’re down to the mount bolts, and then lift the car off the IRS when all the bolts holding the IRS onto the body are undone. The trestle table should ideally be on castors so you can move it about during the rebuild (especially to power wash it. By the way, make sure that when dropping a swing arm, that the opposite side of the IRS is supported, because there is a risk that it might tip over, which could ruin your day)

Now you have all the bits removed you can overhaul/replace the calipers and
discs and as they say in the repair manual “assembly is the reverse of the
above”. Oh and don’t forget to overhaul the handbrake calipers while you
have them off.

It’s tedious and at times a real PITA but it’s do-able, of course if you
have any other work to do on the rear suspension unit such as bearing or
seals etc it would probably be easier to drop the whole cage and work on it
out of the car.