Apologies ahead of time for a long first post, just feeling a bit lost

Basically... front rotors are completely, but evenly (no scouring), worn after less than six months/8,500 miles. Rear rotors are in great shape. Brake pads look almost brand new on all four corners with very even wear. Calipers are not stuck. What happened? Am I a novice overlooking a simple issue?

A little over a year ago I picked up a 2003 Jaguar XJR, with the R1 Brembo package. It has been absolutely bulletproof. I've been wrenching on my own vehicles for a bit over six years now, and have done all of my own work on my other cars. The XJR is a bit beyond my comfort level, so I've stuck to only taking care of the basics (fluids, ignition, fuses, etc) and left everything else to the professionals. The nearest Jaguar dealer is 100 miles from me so I've dealt mostly with two local specialty shops.

When I bought the car there was only about 5,000 miles of life left in the discs, so sourcing a new set began immediately. Had read some decent things about the Centric/StopTech OEM replacements so I pulled the trigger on a complete set from RockAuto. The exact set I purchased were StopTech "Sport" model 128 rotors and model 309 pads, the same ones StopTech indicates for the R1 on their website.

In July I contacted a local indy I had heard good things about. Late-20s mechanic who has a whizkid reputation and a scheduler are the only two employees. (I live in a smaller town so it was between these guys and another shop with a lackluster reputation). I won't dive too far into details but my experience with the shop ended up being fairly negative. Mechanic (and people I trusted) swore up and down he was great with Jags. I wasn't in a rush, so I dropped it off on a Tuesday for a Thursday slot I'd reserved. Next thing I know and three weeks have gone by without any updates. Finally called the following Monday to find he hadn't even looked at the car. I wasn't upset and didn't ask for any rush, but he ended up doing the service the following morning anyway. Seemed like all was kosher until his scheduler reamed me out for "being impatient on a complicated job" while I was paying the bill (also got told to buy a Toyota instead). Wonderful, eh? Have since found a much better, and friendlier shop.

Experience aside, it seemed as if the job was done correctly, and I experienced no trouble with the brakes during and after the wear-in period. Brake balance felt even, with good stopping power and no judder or noise.

Anyway, here I sit a little more than six months later. I've put approximately 8,500 miles on this set of brakes and the front rotors are worn nearly down to the metal, with severely faded stopping ability, yet the rear rotors seem to be wearing properly (I have not gotten a chance to measure thickness on either set yet). The brake pads look nearly new all around. Calipers are retracting properly as well. I haven't driven or stopped the car hard, save maybe once or twice when cut off in traffic, and I always apply braking power evenly and gently. The calipers seem to be retracting properly and the car doesn't pull to one side or slow prematurely. I've seen no excess dust from the pads. There's been no noise or fade from the brakes until very recently when the fronts started to sing a bit while stopping. I have experienced no judder or vibration in the interim, even more strange when you consider that Jaguar's own technical bulletins identify these cars as high risk for disk vibration and prematurely warped rotors.

Probably the strangest thing to me, apart from lack of vibration, is the wear pattern on the rotors. I'll be the first to admit that I'm a novice mechanic but I've seen my share of warped rotors, worn pads, stuck calipers and improperly installed brake hardware. The front disks on the Jag are perfectly, evenly worn with no apparent warping, with matching even wear on the front pads. If this had happened after 15 or 25k miles, I probably wouldn't have batted an eye, but 8,500?

So what am I missing? ... I've already started sourcing replacement brakes, but I'd like to figure out what went wrong so I don't have to go through this again next year.

A few people I have spoken with have suggested that the pads and the rotors were mismatched, which seems strange considering they were from a matching set. However, it definitely does seem like the pads are too hard for the rotors causing the wear. I'm thinking the rears might not have been affected yet due to a brake bias issue stemming from the mechanic who did the job. I read good things about Centric/StopTech so I'm wondering if I should try the rotors again with different pads.

Thoughts, advice, parts recommendations? Thanks ahead of time for any input.

 

??? Rotors are metal. Not sure what you're actually trying to say. Got a picture?

Would help if you measured the thickness also.

 

Sorry, just a lazy figure of speech. The friction surface has worn quite thin and is starting to visibly crack. I haven't gotten a chance to measure the thickness yet as I recently moved and have misplaced the set of good calipers I have. Hoping to grab some from work and get a measurement in tomorrow. Have only been suffering from decreased front brake power for just under a week now.

 

Centric is a very reputable manufacturer.

Maybe a phone call to their tech support line might
yield some info.

 

I've heard similar stories about R1 brakes, but with the original Brembo disks and pads. Apparently the pads are quite aggressive, and have a tendency to chew through cheaper disks. Using genuine disks is meant to help with this.

It sounds like the disks are cheap, and you should possibly consider better ones. Bear in mind genuine Brembos are VERY espensive...
You could also consider downgrading to the standard disks and calipers. They don't look as pretty, but for what you can sell the Brembo calipers for you could buy new calipers, disks, pads, and a full set of spares, and still have half the money left.


I would also be VERY wary of driving around on cracked disks. If they explode they could do some serious damage to the wheels and suspension

 

Indeed. Have since parked the car in the garage until I get to the bottom of this, thankfully is not my primary vehicle.

I've been considering another go with the original Brembos, but I'm hesitant to go with a set of drilled rotors again. The wet performance, superb bite, and lack of fade were fantastic, but I'm definitely not going to be tracking the car or driving it hard. Mainly just use it as a GT for long trips so doubt I really *need* the sheer stopping power at the moment.

I was debating a set of good quality solid rotors paired with slightly softer ceramic pads, didn't know if anyone had experience with this sort of setup with the larger calipers. Not looking to "cheap out" on the upkeep (the recent CATS maintenance will attest to this) , just trying to approach it from a usability standpoint.

 

I won't use Centric ever again after a similar experience with the front of my caddy (rears lasted longer but still wore quickly). Rock Auto sells some nice Power Stop (cross drilled, slotted, center vents, and zinc coated so they don't look rusty after the first rain storm or puddle you drive thru) set ups and I think you can find them on ebay as well. I had good luck with the rotors I got from them on my e39 beemer and the ones I put on my non-Brembo XJR are working well, although they've only been on for 4k miles or so.

 

When I bought my 02 XJR the 03's had already come out ... Jaguar must have had a bunch of Brembo parts leftover at the factory -- all the early cars my dealer received had the Brembo. The Brembo upgrade was why I did not want the 100 when it came out. I also got a killer deal on my 02 ...

The Brembo upgrade had a reputation of being expensive and short lived .... although < 10k is a surprise. 15k would not surprise. A typical XJR will eat the pads by 25k, and rotors at 50k in my neck of the woods. I'm in the midatlantic -- rather flat for the most part. Had a 100 to drive for a week and found no difference in the brakes vs stock XJR.

I too would call Centric -- they may help you out or provide some guidance. Your choices are limited ... unfortunately. Good luck

 

Post the measurements and pics when you have a chance.

Thin and cracked rotors shouldn't affect stopping power though.

 

The biggest reason to get drilled rotors nowadays is for looks. The holes don't really provide much increased cooling, esp compared to the internal venting, and the temp differential between near-the-holes and far-from-holes metal can cause stresses and warping due to uneven cooling. Slotting will improve initial bite at the cost of some pad wear. Most modern drilled rotors don't suffer from this warping unless they're el cheapos, which is why high-end sports cars get away with it. I'd personally go smooth, maybe slotted if I really felt I needed it.

Maybe the cracking is heat-scoring or glazing? That might cause the decreased performance, but it's hard to know without seeing it.

I've been tempted by an R1 retrofit for a while now, but since I keep seeing these issues it might just be worth sticking with my standard calipers and throwing some Redstuff pads and a braided line kit in.

 

This is worth reading, on the difference between adherent and abrasive friction :

Brake Pad Bed-In

Note that during light braking, and at low temperatures, abrasive is the dominant mechanism, which wears the disc more than the pads.

To get adherent braking, you have to get the temperature right up - by braking hard.

My theory is that your drilled rotors, combined with the choice of pads, mean that you never really get into the adherent braking range. In other words, you have the wrong brakes. You have brakes suitable for a race track, with regular braking from high speeds, and you're using them on the road.

You might be able to find pads that work better on the road.

 

Actually I think the holes and or slots help give water a place to go when you apply your brakes, as well as looking cool. The plating is certainly only for looking cooler than rusty rotors as I've never actually rusted thru a rotor but they stand out like a sore thumb when you look at your wheels (IMHO). The extra surface area can't hurt for cooling but I agree the extra area isn't much of an increase over a vented rotor.
My e39 beemer came with vented solid rotors and during monsoon season here it was scary waiting for the brakes to grab. Slotted and drilled rotors on now and no delay. My bikes have all benefited from either coming with holes stock or adding them later.
The centric rotors I wore thru in no time on the front of my sts caddy were the only rotors I've experienced that with. I'd bet on poor heat treatment of the parts. Sometimes poor heat treatment means you've got extra, built in stress that rears its ugly head once heated and they warp. Sometimes you end up with a dead soft part.Maybe they forgot to carburize the surface, who knows but good rotors should give better service than the OP & myself got out of the parts and it's interesting that both of us were supplied by the same company...

 

I try to go with the OEMs discs and pads(jagbitsj, and always make sure I don't overtighten the lug nuts...lug nuts way to tight has warped a few discs on me

Red stuff has worked well for me as centric discs ...for me it was mainly a warped disc and vibration problems...

 

Really sounds like a high friction pad.

"front rotors are worn nearly down to the metal, with severely faded stopping ability, yet the rear rotors seem to be wearing properly (I have not gotten a chance to measure thickness on either set yet). The brake pads look nearly new all around."

I drive my R1 brembos pretty hard; replacing my frist set of front rotors and pads around the same interval. I was running Redstuff EBC pads and Eurospare non drilled rotors. Stuck with the Non drilled rotors but went with a lower friction (very dusty) pad; So far so good. braking does not have the same feel of bite, however the car slows down with similar positive affirmation. If you look, D810 pads fit Aston martins, Ferrari's, Lambo's, and viper....so higher performance pads in this size are the norm.

No idea why the shop would say a brake change would be complicated..... nothing special or difficult about the brembos vs other 4 pot calipers. Personal, finding the brembos easier to change then regular sliding caliper rotors.