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Discussion Starter #1 (Edited)
So, how do you change the front discs on an X260?

Same warnings apply for this method as does the thread covering replacing the X260 front brake pads that I wrote last week. You know your own competency. You do this at your own risk. This is the method I use. I take no liability for what you do to your car, or if you hurt yourself or someone else.

First refer to Part one which covers removing the pads and the caliper.

Follow that up to point No'7 where you remove the caliper and pads from the Caliper Carrier.

Consider putting steering to full lock left if working on the right hand side - to gain better access to the caliper and carrier - and obvs, vis-versa.

Now let's get the photos going.

1. Open the bonnet to find the Brake Reservoir. You need to check this when you push the piston back in to ensure that no oil flows back into the reservoir and over flows.



Reservoir is in the upper left of the picture below.
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Open the cap and ensure the level is not too high. Its actually quite hard to get a good reading - I though it was near empty at first.
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2. Put an old cloth, or something that can absorb brake oil, around the neck of the fill point to catch any overflow oil.
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3. Now you can start compressing the piston back into the caliper housing.
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4. Once the piston is compressed - hand the caliper out of the way - preferablt with the ty-wrap going through the upper wishbone arm. (Mine jumped when I was later smacking the disc with a hammer. The caliper then hit the floor damaging the paint!!!:mad:)
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5. Time to start getting ready to remove the disc. As soon as the wheel is off, apply WD-40 penetraing oil (Thank you Pete) to the T50 countersunk Bolt. Also spray some round the hub that the brake sits on.
By that time you get to this stage, the oil will have done its magic and made getting this bolt (and disc later) off, considerably easier.

Consider belting the bolt head with a decent hammer (toffee hammers will only tickle it). The aim is to shock the bolt and hub, so that any corrosion holding the bolt is shocked and broken.
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You may also want to consider removing the T50 bolt as soon as the wheel is off, and the brakes still applied. Otherwise, you have to do something like below to ensure you have something for the disc to bite against, to counter the torque necessary to remove this stubborn bolt.


Edit - Method for removing the bolt. Important - Make sure the disc will not move, to counter the torque you apply to the bolt. Do not apply pressure gradually. This will only round the head off, if it is a softer metal like Aluminium. Get a ratchet with a decent length handle, Tommy bar, breaker bar even, or if you have a bi-directional torque wrench, then use that with a high setting 160+Nm on left hand thread (you won't bugger nadger the springs inside the torque wrench then). Then set the tool into bolt head, place one hand over the bolt to hold it steady. With the other hand - crank the ratchet, T-Bar, Breaker bar or Torque wrench as fast and hard as you can. (Righty Tighty, Lefty Loosey) The theory is that the short sharp shock will break the corrosion. If you turn the handle slowly, then there is a good chance that the corrosion will hold the bolt, while the head of the bolt rounds off.
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The Umpah Lumpahs are back in town displaying said T50 stubborn bolt - and the reason why it's so stubborn.
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6. Remove these two bolts with a 15mm socket to remove the Caliper Carrier.
N.b. - I did try removing the disc without removing the caliper carrier - can't be done I'm afraid. The gaps are just too narrow as shown below in the 1st picture of Part II, below.
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To be continued in Part II
 

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Oh jeez it‘s a T50 is it? I just ordered a T45 bugger :(
Great write up mate, but surprised you didn’t use a ‘bridge’ on the calliper to ease the piston back into the bore squarely.
 
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Discussion Starter #3 (Edited)
Aye mate - its a T50. I did initially try a T45 after your post the other day - but it felt a bit slack tbh.
You needed a new T45 anyway - so no harm done. I presume you have a T50 already?

As for compressing the piston - as long as you take your time, it goes in no worries. Then again, I've plenty of practice at work with hydraulics.

That's not to take away from your comment at all. Had it started going in at an angle, then yes - a bridge of some sort would have been used, to ensure the piston went back in square.
 

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Discussion Starter #4 (Edited)
Part II.


Narrow gaps showing why you have to remove the Caliper Carrier.
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7.Remove Caliper carrier and give it a clean up, getting rid of the crud where the pads would sit. Once clean apply copper grease to these areas and then set aside.

Get out your big hammer and smack the waldy out of the back of the disc. Once the disk is removed - it might be an idea to clean up the hub where the disc sits. I did this and also applied some copper grease to stop it sticking even worse the next time I do these discs.
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8. Get your new disc and give it a thorough clean with a solvent. Usually Brake cleaner is quite good at this type of thing. Almost like it does exactly what it says on the tin, imagine that!
I also chose to put some copper grease on the inner face that will mate up to the hub.
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9. Fit the new disc to the hub, and fit that pesky T50 bolt from before. Not sure of the torque. Couldn't find it in the workshop manual. AT a rough guess, I'd say no more than 25Nm. I'd also suggest putting a smear of - you guessed it - copper grease on the threads.
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10. Refit the Caliper carrier. Make sure the two 15mm (A/F) bolts still have the washers attached. Torque is 70Nm.
Give the disc another good clean with brake cleaner to make sure there is no grease present at all.

11. Cut the Ty-Wrap holding the Caliper and fit one of the new pads with the tangs, so that the tangs fit in caliper piston.

12. Place the non-tang pad onto the caliper

13. Place the caliper over the disc, ready for the guide bolts.
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Talking of which - no I didn't lub anything. Not the slightest hint of corrosion on the pins or on the caliper holding the rubber sleeve guides. I'll let you know if I get any wobbling through the brake pedal in due time.


You are now at the point when you can follow The How To Guide on fitting the Pads from stage 11.


Hope this helps. Comments welcome.



As an afterthought, instead of using Ty-wraps for hanging the caliper from the upper wishbone, I think next time, I'll use an old wire coat hanger bent into a S Shape.
It'll make things easier rather than trying to do up a ty-wrap with two hands, while holding onto the caliper at the same time.
 
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Discussion Starter #5
So what people's thoughts on this, aside from dangerous?

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The other side was similar. Outer face was fine.

The car had only just reached 13 000 miles.

Plenty of wear on both the pads and the discs left - but I was horrified when I seen this.
The brakes felt fine - but they didn't have the same stopping as the first and second Jags I had.

Given uncertanties with my job and all - now was when I was able to change these out.

Would Jaguar have replaced these under warranty - I very much doubt it, given that these are wear and tear items - but this is horrendous.


I'd seriously advise others to check there discs for corrosion on the inner faces.
 

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It appears to be common on the X260 doesn't it? Possibly the XE too?..
 
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Spot on Pete, that's why I've replaced my rears and fronts getting done this weekend, pending a erm t50 torx turning up and weather.
Cheap shite iron Allan, but as you've said Jag don't want to know, strangely they do still work ok, but I can hear the grinding, so they need to go.
 
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That suggests to me that the inner pad hasn't been pressing hard enough. A sticky calliper.
 

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Discussion Starter #9
That suggests to me that the inner pad hasn't been pressing hard enough. A sticky calliper.
Calipers looked and felt fine when I was pressing them back in John.

Also I've tried braking hard, to the point of activating the ABS, trying to scrub the discs, but I fear all I was doing was scrubbing the pads more.

Given that the outer face is polished as a whole, I'm not sure how you can say the Inner pad has been pressing enough.
If it was dual pistons on either side of the disc, fair enough - but not when the piston is on the inner face.
 

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Discussion Starter #10
Spot on Pete, that's why I've replaced my rears and fronts getting done this weekend, pending a erm t50 torx turning up and weather.
Cheap shite iron Allan, but as you've said Jag don't want to know, strangely they do still work ok, but I can hear the grinding, so they need to go.
No - Jag don't want to know - and this is what is driving customers away in droves.

The new discs and pads are biting well now, smoothly and progressively. The difference is night and day.
 
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Calipers looked and felt fine when I was pressing them back in John.

Also I've tried braking hard, to the point of activating the ABS, trying to scrub the discs, but I fear all I was doing was scrubbing the pads more.

Given that the outer face is polished as a whole, I'm not sure how you can say the Inner pad has been pressing enough.
If it was dual pistons on either side of the disc, fair enough - but not when the piston is on the inner face.
Good point, well made!
But clearly something is preventing that inner face from making full-on contact with the inner pad and I just can't think what else it could be.
 

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Discussion Starter #12
Good point, well made!
But clearly something is preventing that inner face from making full-on contact with the inner pad and I just can't think what else it could be.
Indeed. It's a head scratcher - as theoretically if the outer face is being kept full contact - then inner should be too.

The only thing I can think of is it being crap materials as Gav said.

They did initially start changing them under warranty - but then stopped - probably when they started to realise the scale of the problem.
 
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Good point, well made!
But clearly something is preventing that inner face from making full-on contact with the inner pad and I just can't think what else it could be.
That's why I though John, but have come to the conclusion the rust starts on the outside edge then moves inwards, it's more than surface rust :( Remember Ricks?
 

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I think you're on to something there Gav, and once it starts rusting it wears the pad in that area before the pad can 'scrub' the rust off.

Is it worse on cars that sit for a few days at a time and therefore the rust is too 'progressed' and the pads can't win the argument?...

Still doesn't explain why the two side of the disc differ though, something to do with the manufacturing process somehow?
 

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Common issue with "sliding caliper" brakes. They just don't "slide" as easily as they should, and the slightest discrepancy in the forces needed to move the pads along their mounting "ears" will cause this. Is why I always put some ceramic grease on those areas.

Never seen this issue on cars with pistons on each side of the caliper. Even good old Buttercup (which has those) does not show this issue, and her brakes are pre-historical.
 

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Is it something as simple as a sh1te casting in this area then:
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Too tight an interface with the pad lugs or just too rough maybe?

But with the forces being generated I'd have thought not?

X250's don't suffer this issue as far as I recall, who makes the callipers for Jaguar, any other cars use the same ones?
 

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Is it something as simple as a sh1te casting in this area then:
View attachment 182726

Too tight an interface with the pad lugs or just too rough maybe?

But with the forces being generated I'd have thought not?

X250's don't suffer this issue as far as I recall, who makes the callipers for Jaguar, any other cars use the same ones?
Could be Pete, Teves is the manufacturer I think
 

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Discussion Starter #18 (Edited)
Is it something as simple as a sh1te casting in this area then:
View attachment 182726

Too tight an interface with the pad lugs or just too rough maybe?

But with the forces being generated I'd have thought not?

X250's don't suffer this issue as far as I recall, who makes the callipers for Jaguar, any other cars use the same ones?
You may also be onto something there Pete and Wilf. There was an awful lot of crud there - and I think some of it may have been paint.
Can't say with any certainty. I did take a file to these sliding areas to smooth them off, before coating with copper grease.

Edit - just looked through some of the pics I did initially for the front pads thread. There does seem to have been some binding.
What are the possible extreme outcomes of this? Failure of brakes, crash, injury or worse? I do remember that the caliper was fairly stubborn to remove with the pads. So much so that I had to recheck to make sure I hadn't left anything connected. The pads were also sticky within the caliper once moved away from the disc.

Seems that they haven't masked off the caliper and caliper carrier correctly when painting.
I wonder if VOSA would like to see this thread?
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[snip]...I do remember that the caliper was fairly stubborn to remove with the pads. So much so that I had to recheck to make sure I hadn't left anything connected. The pads were also sticky within the caliper once moved away from the disc...[/snip]
Fair points and good observations Allan.. however, the more I think about it the less I can see this as the problem.. reason being that surely the amount of pressure needed in the hydraulic system to reduce the speed of an all but 1900KG car would overcome any binding you found.. granted it was large to a human being.. but to the braking system?

Maybe it is enough for those that generally only brake lightly and don't brake heavily regularly?

Any thoughts anyone?..
 

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I think the ears/tabs on the pads have something to do with it, as others have said. I have, in the past, had real trouble extracting some pads that have become jammed in the carrier, caught by those tabs.
The pads need to be almost loose and as Allan has done, a generous dollop (engineering unit of volume where 10 smears = 1 dollop) of copper grease applied to the notches. I believe that once a pad has become jammed, no amount of pressure would shift it.
 
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