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Discussion Starter #1
I had my car returned to me today after having had a first service. Earlier in the day the Service Manager rang me to say that everything was fine but I should know that whilst the front disc pads showed normal wear; the rear were 70% exhausted :eek:
It seems that the prime suspect is probably the DSC and maybe the EPB.
After some discussion I came to the view that it was more likely to be the DSC rather than the EPB because I did not have excesssive wear on my 05 S Type, which had the EPB but not DSC.
It seems that DSC in the normal course of driving is intermittently applying the rear brakes and this is thought to be the reason for the pad wear.
Since I am not a "boy racer" I am wondering if I could safely switch the DSC off and perhaps extend the life of the pads :?:
 

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switch it off and go for a normal drive and see how it feels. Im sure you have had a car before without all this electric trickery so it would be a bit like the old days handling wise.
 

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I'd be very surprised if this has anything to do with the DSC. Two reasons, 1. the light flashes on the dash when the DSC intervenes for whatever reason - no light = no DSC intervention, 2. the DSC only intervenes if there is measured wheel slip, i.e. it detects slip between the tyre and the ground for traction based on front vs rear and it detects lateral slip based on measurements of yaw and latac. The XF doesn't have any kind of fake LSD set-up that could be using the rear pads. If you drive with it disengaged for normal use then sod's law says that will be the time you need it.

There is definitely some kind of issue though with the rear pads due to the amount of brake dust, it's just ridiculous. Wash wheels, drive down motorway, rear wheels covered in brake dust, wash wheels, show to customer etc etc.
 

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Discussion Starter #4
There is obviously a debate going on about the pads.
I presume that your customers will include owners of XJ, XK and S Type and it is interesting, reading again the recent remarks of JAG M/T.

[b said:
JAG M/T[/b]]
In reference for the brake pads its ironic you mention the S type as they are the same pad :!:
With the brake set up I think that the rear wear is high but also be aware that the rear pad is half the size and not as thick as the front.
Also the pads we have changed at first service are due to the fact that they won't make the next service.
Most pads are 3/4 worn at first service.The wear rate is quite high compared to other makes but it is comparable to the wear on XJ and XK.
We have also had no problems with customers complaining about the brake performance.
Now the question is; why is it the rear brakes that are suffering :?:
 

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Evening all!

Have just discovered the forum having googled "XF rear brake pads" - had my first service on Saturday [on my 2.7D XF which I have had for 12 months]] and was surrpised to be told tht the rear pads were "80 per cent worn" and will cost £160 to replace. I was interested in the comments above and suggested to the dealer that this should be a warranty item. The reply was that the wear rate is similar to the S type 2.7D [which was my previous car and I don't recall the pads wearing as quickly] and that Jaguar regard this as "normal wear" and not a warranty issue. I might try ATS or similar to see if they can offer a better price to fit the new pads.

I have had a few niggles most of which seem to have also cropped up with others on the forum. I've had a couple of occasions when the engine turns over but the gear knob doesn't rise. The service guy tried to convince me that this was because I hadn't been pressing on the brake hard enough but this isn't the case. The car has therefore got to go back for a full day next week for software upgrades and "diagnostics". A couple of other things need sorting which I can't see previous mention of in the forum - the steering wheel has developed an irritating creaking noise when turning at low speeds. The passengers window goes down as soon as it hits the top of its travel so needs careful "aiming" with the button - presumably a fault with the anti trap sensor.

I am very pleased with he XF overall - I reckon its the nicest car I've owned!

Richard
 

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I was talking to my dealer whilst changing cars on Saturday and mentioned the rear brake wear issue. His comment was that there was a rogue batch of brake pads early on and they should/would be changed under warranty.

Definately worth a go!
 

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Discussion Starter #7
DeKay said:
I was talking to my dealer whilst changing cars on Saturday and mentioned the rear brake wear issue. His comment was that there was a rogue batch of brake pads early on and they should/would be changed under warranty.

Definately worth a go!
It is interesting to learn that but what would be more interesting would be to know what mileage had been covered by the cars with the "rogue batch"
I still am of the view that at about 15000 miles most owners will find that the pad wear will be around 75% and that Jaguar will say that the pads were not sub standard, just a smaller size and a different compound to the pads that were in common use a few years ago prior to the banning of asbestos.
 

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Having also read the posts on scored rear discs I've looked at mine - the drivers side rear disc is noticeably scored and I can feel ridges across the disc which must surely be wearing the pads! The passenger side is not as bad but still not entirely smooth.

I have asked the dealer to check the rear discs when it goes back this week - there was no comment on the discs at the service so I am going to keep pushing!

Richard
 

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Discussion Starter #9
RichardS said:
Having also read the posts on scored rear discs I've looked at mine - the drivers side rear disc is noticeably scored and I can feel ridges across the disc which must surely be wearing the pads! The passenger side is not as bad but still not entirely smooth.

I have asked the dealer to check the rear discs when it goes back this week - there was no comment on the discs at the service so I am going to keep pushing!

Richard
It is interesting that nearly a year ago a few members reported disc scoring and in the main accepted the advice from Jaguar that it was cosmetic and not of any real consequence. A few discs were changed by dealers and I recall that when this was mentioned to a senior member of the Engineering team he replied that the replacement was not an authorised procedure and that the cost would be for the dealer to reconcile.
I suspect that will be the position today. I have to say that I was inspired to bring it up as an issue with the dealer after reading about it here but in the end accepted the dealers view.
I have not given any thought to the surface for a long time, largely I think because I don't now see the scoring that at one time I thought I did.
However, if you are right, would it not be evident on the pad surface that an uneven wear pattern had developed in line with the "ridges" on the disc :?:
 

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My 2.7 XF went in for its first service last week. One year old and 9,500 miles including 2 long trips to the Continent.

I've had the same problem with rear disc pad wear ~70%. Dealer replaced them under warranty with minimum fuss, although I suspect they did this as I had complained earlier about their overall standard of customer service, so I already had them 'on notice'.

The XF is a great car overall but fuel consumption disappoints at around 27 mpg. Slightly miffed at Jaguar that their new, appropriate 3-litre engine for hauling around nearly 2 tons of steel body was introduced 12 months late.

Intermittant Warning light declaring 'DSC Unavailable'-then switching to limp home mode. Dealer found a kink in the exhaust hose which they claimed should cure the problem- we shall see!
 

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pekem said:
However, if you are right, would it not be evident on the pad surface that an uneven wear pattern had developed in line with the "ridges" on the disc
Yes - I would expect the pads to be similarly ridged so if there is still disagreement I will make sure I get hold of the old pads from the dealer.

The drivers side disc feels noticeably "rippled" due to the concentric ridging and I can't believe this is acceptable after 14,000 miles. We shall see!

Richard
 

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Discussion Starter #12
XF-UXB said:
My 2.7 XF went in for its first service last week. One year old and 9,500 miles including 2 long trips to the Continent.

I've had the same problem with rear disc pad wear ~70%. Dealer replaced them under warranty with minimum fuss, although I suspect they did this as I had complained earlier about their overall standard of customer service, so I already had them 'on notice'.

The XF is a great car overall but fuel consumption disappoints at around 27 mpg. Slightly miffed at Jaguar that their new, appropriate 3-litre engine for hauling around nearly 2 tons of steel body was introduced 12 months late.

Intermittant Warning light declaring 'DSC Unavailable'-then switching to limp home mode. Dealer found a kink in the exhaust hose which they claimed should cure the problem- we shall see!
Welcome to the forum XF-UXB :)
I did have a period of DSC warnings popping up in the message centre a while back.
In the end the problem was solved by the replacement of a loom in the engine compartment :D
 

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An update on my rear brakes.

I'm pleased to report that the dealer has replaced the rear discs and pads under warranty. I had put my concerns about the discs and pads in writing to the service manager before the car went in. Initially they said that the disc irregularities were cosmetic but later in the day said that they had found scoring on the inner side of the discs and had replaced them under warranty. No real admission that the ridging on the outer surface of the discs was the problem.


Richard
 

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Discussion Starter #14
RichardS said:
An update on my rear brakes.

I'm pleased to report that the dealer has replaced the rear discs and pads under warranty. I had put my concerns about the discs and pads in writing to the service manager before the car went in. Initially they said that the disc irregularities were cosmetic but later in the day said that they had found scoring on the inner side of the discs and had replaced them under warranty. No real admission that the ridging on the outer surface of the discs was the problem.


Richard
Very interesting and well done to you Richard :)
I wonder what opinion would have been expressed if the car had been taken to a really professional independent brake specialist at the outset. Indeed, I am now wondering if there would be merit in taking mine into one, if ever I could find such a place, since I have been told that it is acceptable that 70% of my rear pads have been worn away after 15000 miles :?
 

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pekem said:
[
I wonder what opinion would have been expressed if the car had been taken to a really professional independent brake specialist at the outset. Indeed, I am now wondering if there would be merit in taking mine into one, if ever I could find such a place, since I have been told that it is acceptable that 70% of my rear pads have been worn away after 15000 miles :?
]

I was thinking of doing this if they had not agreed to covering under warranty. I asked then to return the worn pads to me if I was paying! The AA offer inspections https://www.aacheck.com/viproducts.asptbut the cost is not far off that of fitting new rear pads!

Richard
 

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Discussion Starter #16
RichardS said:
pekem said:
[
I wonder what opinion would have been expressed if the car had been taken to a really professional independent brake specialist at the outset. Indeed, I am now wondering if there would be merit in taking mine into one, if ever I could find such a place, since I have been told that it is acceptable that 70% of my rear pads have been worn away after 15000 miles :?
]

I was thinking of doing this if they had not agreed to covering under warranty. I asked then to return the worn pads to me if I was paying! The AA offer inspections https://www.aacheck.com/viproducts.asptbut the cost is not far off that of fitting new rear pads!

Richard
Thank you for that Richard.
That is a brilliant suggestion :)
 

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I know I'm onto something here but I don't know what. In other threads you will see that I've been exploring the poor fuel economy and excessive brake dust thing and I hit the problem/solution about 2-3 weeks ago. I switch the DSC to fully off every journey (10second hold on DSC button) and hey presto - indicated fuel economy now 39.x from a steady 31.x previously and... no brake dust. When I say no brake dust I mean very little when compared to pre DSC-off mode.

DSC: I understand that DSC will, if pushed hard enough (and beyond it reducing power), apply individual brakes. To do this then surely it (the system) needs to know precisely where the brake pads are so it can control the precise amount of fluid needed to obtain the precise braking required. How else is a system that functions like this going to know where the brakes are unless it supplies some 'sensing' pressure.

These are just my musings but there is no doubting that I'm onto something. The visible clues and the fuel economy since I went DSC off speak for themselves.
 

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Discussion Starter #18
Qhunter said:
I know I'm onto something here but I don't know what. In other threads you will see that I've been exploring the poor fuel economy and excessive brake dust thing and I hit the problem/solution about 2-3 weeks ago. I switch the DSC to fully off every journey (10second hold on DSC button) and hey presto - indicated fuel economy now 39.x from a steady 31.x previously and... no brake dust. When I say no brake dust I mean very little when compared to pre DSC-off mode.

DSC: I understand that DSC will, if pushed hard enough (and beyond it reducing power), apply individual brakes. To do this then surely it (the system) needs to know precisely where the brake pads are so it can control the precise amount of fluid needed to obtain the precise braking required. How else is a system that functions like this going to know where the brakes are unless it supplies some 'sensing' pressure.

These are just my musings but there is no doubting that I'm onto something. The visible clues and the fuel economy since I went DSC off speak for themselves.
It seems that you are indeed on to something and your theory is lent weight by the comment I received yesterday from a Dealer Service Manager. See post viewtopic.php?f=26&t=1095&p=9014#p9014

I am having the rear pads replaced today and I will make an extra effort to switch the DSC off; it is a pity that it is on by default.
 

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I'm not an expert on DSC and indeed if truthful not sure exactly what it does. Presumably switching it of each journey must affect some element of safety? Therefore perhaps not the best idea
 

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Discussion Starter #20
As I understand it DSC will apply braking on the rear wheels individually when the sensors judge that the car is sliding or slipping out of control. Going round a corner and losing the back end is a good example I think.

However I am still confused with the operation of it because I was told yesterday by a dealer Service Manager that it is not possible to turn the DSC off fully :!:
It can be changed to what was described as "Track Mode" but at no time will the system be completely de-active. I imagine that statement will be read as nonsense by some people and I can only say that is what I was told.
If anyone can say with any authority whether it is right or wrong then I am sure a number of us would be very interested to learn :)
 
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