[Pete McK]

Hi all,
Just had to change all 4 discs (& pads, obviously) on my XE. It’s covered 16,000 miles from new in just under 2 years but in the snow in 2016 it was only really driven once or twice a week. There was what I though was surface rust, not uncommon with current brake discs. I thought it would clean up with use...
Pics of the fronts. Rears are worse. At least they’re easy enough to do
Pitting on the old discs would likely clean up on a lathe and leave enough material for use.

 

[mentepazza]

Don’t know what to say. New material for disk last this much?
Ora maybe something wrong with your disk?
Mine on 23k miles in 2 years don’t look like that at all. Xf, we probably have same disks.

 

[Gav]

does look like the pads have only made contact on a small area of the disk, what's the back like?

 

[Pete McK]

That is the back of the disc. The front has 3/4” on the outer edge which is pitted. There was full pad contact before last winter.

 

[R17]

That is similar to mine, as noted at Donnington......

Had MOT in November and apparently passed brake test with flying colours - I am due to replace rear pads and did think about re-using disks, just to see if it would clean the surface all over, as the disk thickness is still meaty

Did you change yourself/OEM?

 

[Pete McK]

I did hear somewhere that it’s down to not putting chrome in the discs any more. Not sure how true that is, discs didn’t used to go like this.
Bought genuine Jaguar parts and fitted them here, fortunately the caliper rewind tool I use for the Panda fits perfectly. Apart from a 7mm Allen bit and a reasonably large Torx to hold the disc to the hub there’s no special tools needed.

If the discs are the same as mine do you want my old rears to see if you can skim them up?

 

[Gav]

hmmm, I wonder if this is a slider pin issue as it doesn't look like it was square to the disk, what shape are the pads in?

 

[R17]

I did hear somewhere that it’s down to not putting chrome in the discs any more. Not sure how true that is, discs didn’t used to go like this.
Bought genuine Jaguar parts and fitted them here, fortunately the caliper rewind tool I use for the Panda fits perfectly. Apart from a 7mm Allen bit and a reasonably large Torx to hold the disc to the hub there’s no special tools needed.

If the discs are the same as mine do you want my old rears to see if you can skim them up?

It wouldn't surprise me that it is some kind of cost-saving measure, as my brakes still feel phenomenal!

There's quite a few other X760/X260 that I know are in the same state...........I have halved my mileage, and this was only noticed after this point

Thanks for offer Pete, but I fancy some MTEC discs - may purchase and skim my old ones

 

[Pete McK]

The

hmmm, I wonder if this is a slider pin issue as it doesn't look like it was square to the disk, what shape are the pads in?

The pistons, sliders and pins are as free as a bird. I did glasspaper the discs about a month ago to try and clean them up but I had to chip 1mm of rust from the outer face of those front discs, revealing the pitting which won’t clean up without machining.
It’s just down to lack of use in that winter, believe it or not. I wonder if the discs are made from recycled Morris Marinas

 

[OBC John]

Cast iron will only corrode like that if you leave it. If the disc is in constant use, then whatever surface corrosion occurs will be regularly stripped away of course, when braking. For the corrosion to eat that far into the disc it must have been out of use for some time. And once the pits have formed, the corrosion can continue where the brake pads can't reach.

 

[R17]

You mentioned 'rewind' tool - I thought there was an electronic procedure for the rears??

 

[Pete McK]

It wouldn't surprise me that it is some kind of cost-saving measure, as my brakes still feel phenomenal!

There's quite a few other X760/X260 that I know are in the same state...........I have halved my mileage, and this was only noticed after this point

Thanks for offer Pete, but I fancy some MTEC discs - may purchase and skim my old ones

The MTEC might be more corrosion resistant.
The XE brakes still worked well but weren’t silent, however they do perform considerably better now!

 

[Pete McK]

You mentioned 'rewind' tool - I thought there was an electronic procedure for the rears??

I think it consists of ‘hold the handbrake ‘off’ button down and press engine stop’ to stop the handbrake putting itself on.

 

[Pete McK]

Cast iron will only corrode like that if you leave it. If the disc is in constant use, then whatever surface corrosion occurs will be regularly stripped away of course, when braking. For the corrosion to eat that far into the disc it must have been out of use for some time. And once the pits have formed, the corrosion can continue where the brake pads can't reach.

Yep, it was only driven once or twice a week for a while. Looks like it needed a lot harder use on those days!

 

[R17]

I think it consists of ‘hold the handbrake ‘off’ button down and press engine stop’ to stop the handbrake putting itself on.

See post #42
https://www.jaginfo.org/showthread.php?93409-XE-240-Rear-Brakes/page3

 

[wilf]

You mentioned 'rewind' tool - I thought there was an electronic procedure for the rears??

There is, but that just stops the EPB from activating. The adjustment in the rear caliper is via the pistons that have to be "wound back" (i.e. screwed in). Same as any other Jag rear brakes.

 

[OBC John]

You mentioned 'rewind' tool - I thought there was an electronic procedure for the rears??

I think all brake callipers that are connected to a hand-brake/EPB have to be manually rewound.

 

[R17]

There is, but that just stops the EPB from activating. The adjustment in the rear caliper is via the pistons that have to be "wound back" (i.e. screwed in). Same as any other Jag rear brakes.

Well in that case I can utilise the method I used on my X250

 

[OBC John]

Well in that case I can utilise the method I used on my X250

Take it to Sunday Club?

 

[R17]

Take it to Sunday Club?

I do my own work
https://www.jaginfo.org/showthread.php?9276-Changing-Rear-Pads-(2-2)