So driving down the highway this morning all of a sudden my "Brake Pad Warning" light pops up. Stranged considering I wasn't even applying the brakes. I am going to have it checked out by a local Jaguar Indy..but in the meantime Jaguar Dealership sent me the following quote! Sounds high!

2012 Jaguar XFR
Front Brake Pads
2 Brake Rotors (not turnable-hi performance)
Front Sensor (brake light)
Brake Clean
Stop Squeal
Labor
991.89 + tax

 

How did the dealership find out about the warning light? How did they know it's the front brakes and that they are worn?

Pads for and XFR are no more expensive than for other similar models, ie $75- $150ish. Only replace the rotors if they are at or below the min thickness dimension.

 

Also, I call BS on the brake rotors being "not turnable - high performance".
I had new brakes pads fitted to my XFR four months ago and at the same time I got all four brake rotors machined. They still had well over a mm to go before they hit minimum specified thickness, and they are plain carbon steel just like 99% of brake rotors.
Not a problem with the brakes ever since, and I've been on some spirited runs through the twisties giving them plenty.

 

Sounds like you should buy some aftermarket pads and rotors (if they don't meet measured thickness), a sensor then find an independent shop.

 

Modern brake discs are thin for several reasons. They are not high performance just lighter than older discs used to be. Metallic pads wear them out at about twice the rate previously.

The reason the discs can't be turned is they would then be below the discard thickness. Generally speaking there are two "discard" specs. One is supposed to be stamped on the disc and discs measuring below that stamped number must not be refitted. A reputable mechanic will refuse to do so. There is a separate minimum thickness for a disc that is to be turned. A reputable mechanic will refuse to turn a disc that is at or below that slightly thicker spec.

The other problem with fitting worn discs whether turned or not is they will reach minimum thickness before the second set of pads is worn out and at that point must be discarded.

Opinions on this board differ but brake experts do not. While technically a worn disc can be refitted with new pads it is not economically sensible to do so unless you plan to drive on unsafe brakes at some point by refusing to discard the worn discs before the second set of pads is worn out.

A dealership will have to charge about 1/3 more than the usual independent shop for parts and for labour. That's just the cost structure they have to deal with. Since Jaguar doesn't manufacture the brakes and there us nothing technically different about Jaguar brakes it is not a job the dealership would need to do for you.

 

Have the same issue right now. Car is currently at the dealership with quoted price around $1800 for front and rear pads and rotors (dealership says that rotors are single use and must be changed each time. Strongly considering aftermarket pads and rotors, was wondering how that would interfere with sensors for brake wear or if that's on the caliper itself?

 

So I just came back from an local independent Jaguar shop. They verified that the rear pads are worn out and the rotors are below minimum. So they quoted me $700 (OEM Parts and Labor).

$300 cheaper than the dealership!

 

Brake pad wear sensor is a separate item from the pads. They are not reliably reusable even if not triggered. You can easily short the connectors with a jumper wire if you wish to fit new aftermarket pads with no wear sensor.

Since the discs wear out with every set of pads there really is little point in a pad wear sensor unless you really don't know how to tell his worn your pads are by just looking at them from time to time.

 

If interested, you can reduce the price by another order of magnitude by using quality aftermarket components and DIY.

It's not rocket surgery.

 

Thanks. They offered my aftermarket as well but I refused based on previous experiences with pads and rotors.

 

Aftermarket discs are usually fine as long as you don't buy really cheap ones. Cast iron is pretty much cast iron and the major brands are reliably good. Indeed, I expect the discs are pretty much all made in a few factories around the world and sold to various brand owners such as the much feted "Brembo". Cheap discs from no name or "special brand" suppliers may well have casting flaws not showing up until the discs wear.

Aftermarket pads can vary a lot in braking efficacy.

Ceramic pads are sometimes touted as "dustless" but they aren't. They just produce beige dust instead of black dust (so don't expect dustless appearance on graphite or black rims). It is not possible to manufacture dustless pads as is obvious from the fact that they wear out. You might wonder where the disappearing pad material goes. Some of it inevitably ends up on your wheels.

If you care about braking distances be choosy about who you buy pads from. The advantage of OEM is no possibility they will be inferior to what you have. Jaguar doesn't make discs or pads but they get what they demand from their brake suppliers.

 

Actually, that's misleading. Brake technology is very much a sophisticated engineering process as you will rapidly discover should you be unlucky in your purchase of aftermarket components. Just as there are cheap and nasty tires there are also cheap and nasty brakes. Both could cost you a lot of money if not your life.

 

That's why I included the word quality in my post. There is lots of junk out there, so doing your research (here) ahead of time is worthwhile.
OEM parts are not the only game in town.

 

As far as I know, there is one minimum thickness specification.

And that specification is for the minimum thickness at the time of
fitting with fresh pads. The engineers have already allowed for the
wear that would occur during the lifetime of that set of fresh pads
when determining the specification.

As for the fetish for new rotors on the part of technicians, this is
due to the desire to avoid comebacks and to avoid waiting for
the rotor to be turned. Time is money.

As for turning itself, maybe not Jaguar, but for many makes a
on vehicle brake lathe is required equipment as set by
the manufacturer. This is to address warranty concerns about
brake vibration, even if the technicians avoid the same facility
for retail work.

++

 

There are two. The one stamped on the disc is the discard thickness of a worn rotor. It should be discarded when thickness reaches that figure regardless of pad wear. The other will be provided by the disc manufacturer to brake mechanics telling them how much can be safely machined off. They are different numbers.

 

I intended to point out that your remark about rocket science was not apt. Brake technology is very complex and far beyond the understanding of most car owners. You used a common saying implying that selecting brake parts is easy. It is not and it is safety critical for you and people ahead of you.

 

BREMBO are located world wide and have been making disc rotors since 1961
they do not buy from factories around the world , they sell to them .

The only disc rotors that can't be machined or turned are Composite Carbon rotors .

IF a new rotor is made to be 30 mm thick , and the wear limit or scrap thickness is 28 mm , that's it , there are no other wear limit specs for anyone . The only other stamping on the rotor is production date , factory location code or brand name .

The nuisance dust on your wheels is not just brake pad dust , guess where some of that 2 mm of missing rotor is , yes also on your wheels .

Earlier style of brakes used the friction material of the brake pad to pull up the car , so disc rotors because of this , were made with a lot of steel and almost bullet proof and were expected to last the life of the vehicle , which they did .

Modern rotors are " sacrificial " , they are designed to wear like brake pads but at a slower rate , most rotors are made up of cast iron , carbon powder and resins ,
some more expensive brands add an additional compound of silicon carbide for extra strength .

Although is it fair to say that a thicker rotor will dissipate heat better ,
any rotor that is within it's wear limit can and should be machined with out any concern
for safety or performance , don't be told otherwise , they should not be replaced just because your pads are worn out .

To-days Brake pads are missing that vital , but deadly substance ( banned here in 2003 ) that made them work so well , Asbestos .

I know that people responding to this thread may already know about all of the above

But there are some who don't .

 

and I have already run into aftermarket(quality) and not cheap pads that did not fit the calipers correclty without removing the stainless shims. And reminds me of the earlier X and Stype debacle over this same issue of tall and short pads, with or without shims. Over my years of working on and owning 7 jaguars I have found best braking and feel to be OEM, until I used EBC redstuff, great feel, lower dusting, shorter measured stopping distance and no brake fade from high speed stops. Now thats all I use on mine or recommend to other based on my preference and experience. Either EBC or OEM. Proper brake in and use are very important also as is CORRECT use. Something many women dont do and some men. LIGHT FREQUENT BRAKE APPLICATION LEADS TO GLAZING, SQUEELING AND POOR BRAKE PERFORMANCE.
You dont have to hit you brake a 100 times in traffic or start braking a half mile before you need to stop. I can always tell a light braker by the pedal feel. you can't activate ABS if you STOOD on the pedal! To deglaze I brake hard several times in reverse from the rev limited reverse speed until I get good pedal feel back. You would be surprised at the difference

 

Metal brake discs are made from cast iron. Steel is unsuitable.

Brake discs have a minimum thickness stamped into them. They also have a minimum machining thickness specification which the disc manufacturer can give you. That number is not stamped into the disc. You may not machine a disc that is already below this specification even if not yet at discard thickness.

Cast iron disc "particles" from disc wear are, surprise, surprise, cast iron and do not end up in your wheels, fortunately. If they then you will notice the rust spots embedded in the wheel paint.

Asbestos is not necessary for braking performance and certainly not essential. It was used merely for convenience, not performance. It has been banned from most uses.

If you think Brembo casts all their own discs that's fine. I doubt that very much. Maybe they own all their own production facilities but I can't see why they would. Discs must be discarded when they are worn below minimum thickness regardless of pad wear left. Whether you wish to fit new pads to worn discs is of course your decision but for Jaguar discs it is a waste of money or your labour as the case may be to fit new pads to worn discs.

 

Your post is spot on but of course gets trumped by those who invoke the word 'safety'. Gots to think about the children ya know.