Nice OB - following along.
I have been looking at pad options to make a better hand brake pad.
As I have motorbikes I looked at bike pads and the backing plate is much narrower like the XJS... problem was pad thickness.

I went to a Honda bike shop and the spare parts dude looked at what I was after and said look at ATV pads - 4 wheel bikes.
Especially the TRX500 - which the rear pads are quite thick.

Problem is I have not got my hand on one to see if it could work.... looks promising and made by EBC.
No idea on dimensions at this point, but most of my bike pads are bigger and could work if they were thicker!

I am looking to buy a set from China for like $5 and see how it looks and go from there and buy quality pads to mod and fit.
Mean while - no hand brake.

 

Hi Duke

I'm probably not the best person to ask, as this Mod was 'Greg's' idea and I haven't got around to doing mine yet, so probably better to wait and see what he says

P.S. If you were thinking of doing your Cage, either now or sometime in the future have you thought of re-purposing your 'Air Jack' that you use to lift up your Car Ramp, as it could be just the thing for lifting up the rear under the diff

 

Dam OB - that is a great idea.....trying to do it with out at this stage....

 

Woke up this morning and ready to remove the Cage from the Diff, only to find it was chucking it down with Rain and so instead I spent the Morning phoning round to find a Firm to recondition the Rear Calipers on '50 Shades' my Grey XJS where I was prepared to pay £100 to do this job

Having had a Bad experience in doing this Job myself, when a Seller on ebay caused a Major Problem by sending me the wrong Caliper Pistons for my Merc where the size on the Box didn't match the Contents being a few thou undersize which left me without any brakes!

So that sort of Coloured my thinking about doing this job on the Jag, as you don't want to keep on 'dropping the cage' just for the hell of it if things go wrong, though on the way to nowhere, I found out something very interesting!

Where I found when I phoned round that some of the Firms who do this job had almost doubled their prices to what they were before lockdown and one of them even quoted me an eye watering £300 to recondition the pair!

Not sure why I was panicking, as the GF usually comes up Trumps when it comes to finding this stuff and so I thought I would leave it to her and as it had stopped raining it was time to get on with the job



Although I've heard its possible to change the Rotors and Calipers with the Shroud still on the Cage, I know from past experience that its so much easier to see what you are doing if you take the Shroud off



There's really not that many bolts to undo! These two big ones at the bottom, another four on Top then disconnect the drop links either side and also undo the ones on the bottom plate plus one or two other little bits and pieces



Undoing the Four Top Bolts on the Cage



As I wanted to save the Original Brake Pipe I had to use some Heat to get it undone so I could use it for a pattern to make a New one



Undoing the Bolt that holds the 'Trailing Arm' unless you happen to have a Car Lift trying to undo this bolt can be a bit of a 'Nightmare' as a part of the head of this bolt is cut off (OEM) so you can withdraw it, which can also make it hard to get a Spanner on it and even then its screwed in really tight which is why I had to use a lever on it



Mega Awkward or what but I thought it was better to get it loosened off now, than try and do it later when it was back on the Car, just in case I ever wanted to either change or re-bush the Trailing Arm



Using a piece of 1/2inch Copper Water Pipe to make a 'dummy shaft' to help to keep everything aligned 13.4 inches long and I'll also cut the damaged end off when its done



As you knock the 'dummy shaft' in the Steel Shaft gets knocked out the other side!



Another 'Shot' of that 'Quirky' Trailing Arm Bolt which I managed to undo with a 19 mm Ring Spanner and a Scaffolding Pole as a lever

And then it started Raining again so I had to abandon Ship until tomorrow

 

But it didn't start off that way as with lots of lovely Sunshine things were looking up as it didn't take any time at all to take the Cage off the diff, as if you are going to do any work on either the Rotors or Calipers removing the Cage is very well worthwhile, as for one thing everything is easier to do

Where one of the first jobs was to remove those 'pesky' handbrake Calipers, which are fixed to the Rear Calipers with just a couple of bolts



Removing the Handbrake Calipers was easy! 'Almost a non event'

Not so with removing the Rotors, just look at the Damage!



A massive great chip on the edge of the Disk could have caused big problems later on, so time to replace the Rotors with some New Ones except it wouldn't be that easy and here's why



The Nuts on the Rotors were seized solid with Rust, so undoing them could have presented a bit of a problem!



There was really only one thing for it, time to break out the Impact Wrench and go for the Nuclear Option! which whizzed them off in Seconds and did an amazing Job



One of Lifes unanswered Questions!

Can you remove the Rotors without removing the Calipers? The Answer to that Question being NO! (not even if all of the Brake Pads have been removed)

Which I'm sure is going to Surprise a lot of people who thought this might be possible, although I am going to qualify this by saying it 'May' be possible if your Car is fitted with a 'Dana Diff' as on many if not all of the 'Lucas Cars'

At which point I've now arrived at a point where I now have a really major problem to sort out, as all the Caliper Bolts are Rusted Solid where even with heat and a Spanner so well fitting that you have to hammer it on, all of those 'Pesky' Caliper Nuts will simply not undo, where to make matters worse there's no room to manoeuvre

And so the only option I can see is to Weld a Spanner to the Nut, unless anyone else can come up with a better idea?

 

Good job OB. I think k both you and me are eahpoy spring is here and we can get back to it lol.


Have u tried a hand held manual impact? So uts basically a cylinder with a drive on the end and you put your socket on it and then you hit it with a hammer. Looks like this. I have a 3/8 drive one. Only turns just a little bit when you hit it. Might be enough to break the rust

 

OB
I would souse the bolts in "the Mixture" for a bit. Can you post a close-up of where the bolts actually are, as on my Dana, they are, as you say, in a different place. Also, FYI, the calipers have to come off on the DANA to change the discs too!
I think welding a spanner is risky, have you got a ring-spanner of the right size, plus a long tube to go over it to extend the overage? I cannot see that a ring spanner would apply any less torque than a welded-on one; and will not **** the bolt head which welding might.

 

Hi Greg

I'll try and get a Photo for you later but the Head of the Caliper Bolt is nearest to the diff with the end of the Threaded Part pointing towards the Brake Disc, so if you could back off the Bolt far enough then the Head of the Bolt would be touching the Diff

The Big Problem being that no ring spanner will fit it, certainly not the Metric ones and the only Spanner I've got that's a really tight fit, is an open ended BSF one but the jaws of that came loose when I put a scaffold pole on the end for extra leverage and there is certainly no room for a socket

If you happen to know the Size of the Spanner I need I can try and get one but there are no Shops in the Town where you can buy anything but bog standard Metric as the Head of the Caliper Bolt is a really weird size

If I could get a Ring Spanner on it, then I'm sure I could shift it

 

OB,

Tell me the size of that BSF spanner or if anyone knows the correct (Imperial?) size if that bolt head, I'll see what I've got in the garage.

Cheers

Paul

 

Paul, OB
The bolts are A/F-sized heads and METRIC FINE threads! Cool eh! This is because Girling went to 100% metric on their brake stuff well before jaguar went to metric on their cars. They bolt head is the same as the front caliper bolts, which are the same cool combo! So check the fronts. From memory they are either 5/8ths. 11/16ths or 3/4 A/F. But do slosh on the "Mixture" OB!
OB, as you loosen the bolts, assuming you get to this wonderful state! the disc/caliper combo is moved outwards, thus allowing the bolts to be comletely undone.

 

Hi Greg@Paul@Rescue

Here are a couple of Photos of the IRS including the elusive Caliper Bolt Size which was the same problem that I had last time, where I managed to undo them with an open ended Spanner which was a BS (something or other but can't read the size on it now)

Those Caliper Bolts were really tight but these ones are even tighter and will either need the Correct Size Ring Spanner or Maybe a Metric Nut Welded on to the head of the Caliper Nut, so at least I can undo them and then buy some New Replacements

If I knew what Spanner Size I needed, then I could order a Couple of those On-Line, as I am going to need them to tighten up any New Bolts, as I will have to wait for some more New Brake Discs to arrive, so I'll have time to get some Spanners when I know what size I need

Rescue: I've got one of those Impact Drivers but no room to use it for this particular Job but thanks for the suggestion anyway

Paul (ptjs) Thanks for the offer of a Spanner but I'll try and buy a Couple while I am waiting for New Discs to arrive, once I know what Size I need as I am going to need them in the future

Greg: Thanks as always, your Engineering Knowledge is Second to None!







A Caliper Bolt from another IRS but what Size Ring Spanner will fit it?

 

Alex
That is 3/5ths A/F. But you MUST give it the mixture every 1/2 hour for a couple of days and they will fall out with a ring spanner.

 

Hi Greg

Cheers! I'll give that a try and let you know what happens

But I cannot find anyone that sells 3/5th A/F Spanners

As a Side Note G.F. Advises that no one she knows has ever used 'Cool' since late 2019 as the word 'Cool' is so 'Rinsed' so probably not advisable to say your XJS is 'Cool' when she may be overheating! or even say 'My XJS is 'Sick' for obvious reasons, in the 'ah hem' unlikely event that she's broken down

At the time of writing, the 'Buzz Word' is 'da bom' most normally prefixed with 'is' and using the suffix 'init'

e.g. My XJS is da bom or more normally My XJS 'ista bom innit'

If she comes up with anything else, then be sure that I will let you know

 

Alex
My education is greatly enhanced by this linguistic knowledge of modern English. Clearly I have been an expat for far too long.
Buy your ring spanners from ebay, e.g.:
https://www.ebay.co.uk/itm/32pc-Span...0AAOSwSv1XkJpC

And loads of top quality second hand ones too!

 

Greg / OB,

At the risk of questioning your knowledge, Greg, and your measurement OB,

..isn't it more likely that the bolt head is the more common 5/8" rather than 3/5"?

5/8" is ,625 inches which is 15.88mm
3/5" is .6 inches which is 15.25mm

I'm guessing that with surface rust, the potential for being slightly flared after being turned etc, that the bolt head is really slightly smaller than the indicated 16.05mm, so perhaps closer to 15.88mm?

Just a polite suggestion, Guys!

Cheers

Paul

 

Not that a remember the flashback and trauma from doing the rear end those caliper bolts are super tight. Iirc I used 5/8 stubby wrench and once I got the stubby on it used some sort of leverage to break it free. I soaked it a day or 2 in pb blaster first.

Also I remember that once the bolt is out of its hole there's barely room to wiggle it out.

Same goes for reinstalling. You have to put the bolt in just so it sits in the hole part of the France before u put the caliper back on. I'm lucky i have smaller hands as some of these jobs there would have been no way I could get a finger on something. I'll look back at my.pictures and see if I have anything useful

 

Paul, OB
I am sure that Paul is probably right. 5/8ths would be far more likely. By the time the spanners arrive the mixture will have done its job!

 

Paul (ptjs) was absolutely right 5/8th was the Size Spanner that I needed and after turning the Garage upside down I found one! together with a FBH with which to give it a 'Clonk' which was not quite so straight forward as it sounded, as there is hardly any room to manoeuvre

So next I did what 'Greg' suggested and replaced the long tie rods, so that I could lay the IRS on its side to get to the bottom Caliper Bolts, after whizzing off the Bolts for the Rotors with my Impact Wrench



The Caliper Bolts were very tight and also awkward to get to



This time when I dismantled the Cage I left the Bottom Plate attached to the Diff which in the event worked really well as although the Rotor only cleared it by 0.5mm it did save a lot of the 'agro' of having to remove that Bottom Plate



After what seemed like forever I eventually managed to get one Caliper off closely followed by the Second one, where I also decided to leave all the Brake Pipes in place, as I am intending to rebuild these Calipers myself though not sure whether it would be best to use the Original Pistons, as from what I can see they still look good



Yass! at last I've got it all to bits which took Five Hours! not too bad when considering what an awkward job this is



Already for the Big Clean up but that can wait until another day! so maybe make a start on that Tomorrow

 

When I did mine last year I rebuilt the calipers. The pistons and rebuild kits are cheap.

 

Good Job OB - wow the salt does make stuff rust... one picture I was sure you had pulled the disc from the ocean....
How far will you be going to clean the cage?