A question about brakes. I have put new rotors and two sets of pads on the rear of our XF, Rotors and pads at 22000, pads at 40000. At 45300 I was advised we needed front rotors and pads, pads under 2mm, rotors groved, and rear pads in 3-5mm range. I questioned about the wear out rate of the pads, and the fact that the rotors are wearing out so fast. The service writer is supposed to be looking into this but was told it is not uncommon. The car is not driven hard, no hard sudden brake applications. So I am asking if this is normal brake wear?

 

Based on the information I received from my dealership, 45k is the time to change the rotors and break pads. I say this because I brought my car in for the 40k service. At that time, the service advisor told me that I would need the rotors and pads in about 5k miles. I purchased my XF SC with 35k miles already on it. The previous owner had the rear pads and rotors done at 32k miles. The dealership is going to charge me $709 for the rotors/pads.

What does your dealer charge?

 

For current Jaguars this is normal brake wear. The rears wear at twice the rate of the fronts. The normal wear for front brakes is under 50,000 miles. My rear bakes are completely gone at 25,000 miles (44,000 km). Fronts are about half worn. Live with it in return for the superb braking performance plus excellent traction and stability control. The rear brakes are almost entirely responsible for traction and stability control.

 

Don't grooved rotors actually have MORE surface area for stopping?

 

No way rear brakes wear more than front. NO WAY! All the cars load is up front. I believe the work done by the brakes is more like 60F 40R. The only reason I can understand this is happening is that the first owner changed the front pads first. Then your rears wore out making you beleive they wore out before your rears. This rule holds true for all vehicles except jet air planes.

 

Thanks for the info all of you provided good info. The dealer wants 760.00 for the job. I am thinking of r/r my self, with oem type items. It looks fairly easy, famous last words. On the wear out ratio, that doesn't hold with traction control, the rear brakes are used to stop wheel spin. I brought this up with the service dept, to see if it could be backed off some. Once again thanks

 

There are quite a few posts that mention rear brake pads wearing out extremely fast. Everyone should keep an eye on them in their XF.

 

One would think the fronts would always wear out much faster than the rears. Honda has the same problem and does the rear brakes under warranty for free as they notice this is a real issue and the customer should not have to pay for it.

Has anyone looked deeper into this issue?

 

The rear brakes wear out faster then the front on alot of models. My saab needed rear brakes 3 times to 1 time for the front in 80k miles. I think its partially a problem of rear pads are substantially smaller then fronts. Also many manufacturers use the reat brakes for stability contron and traction control.

 

The only disadvantage to grooved rotors (concentric rings, not slots) is the pads wear out more quickly because the grooves in the rotor produce matching grooves mirrored in the pads so minimum pad depth is reached a bit earlier. Otherwise, concentric grooves in brake rotors have no effect.

There is greater surface area but that doesn't improve braking. Greater surface area reduces pressure proportionally. Brakes work by converting kinetic energy into heat and dissipating it. Street brakes work well over a wide temperature range but are thermally limited. Grooving might delay the pads reaching fade temperatures but I doubt you would notice.

 

I have noticed that the rear brake rotors in my 2012 SC are now the same size as the front rotors with nearly the same amount of braking surface. The rear rotors in my 09 SC were much smaller than the front rotors with much less braking surface. I hope that the larger rear rotors in the 2012 will equalize the front and rear brake wear.

 

The opposite. The grooves or slots or holes decrease the surface area that comes in contact with the pads.

 

Slotted and cross drilled rotors also help with heat dissapation

 

Heat dissipation is only a factor when brake fade is experienced. Street driven Jaguars don't suffer from brake fade.

 

I replaced all my pads with Porterfield at 10k miles because I got tired of the extremely dusty OEM pads. At that point, the rears were almost gone, while the fronts had plenty of life left.

 

I think he means concentric grooves resulting from rotor wear. These do increase pad to rotor contact area but without effect.

Slotted rotors are basically a gimmick. They slightly increase pad pressure due to slight decrease in contact area ( only one slot is under the pads at any given point). They are said to reduce pad float due to pad gassing to which I say BS.

Drilled rotors are a really dumb idea unless the drilling is done correctly. The holes do improve rotor cooling and help dissipate water on initial pad bite. But to benefit you need to really punish your brakes. Waste of money.

Ironically, drilling or slotting can actually degrade brake performance if it keeps the rotors too cool. Also, pad wear rates go up and the slots or holes can make noise.

 

I'd get a set of Torx bits if you're planning a DIY rotor change....I needed them on the Rover and I see some torx screws in the engine. Why the Brits use them......I don't know...

 

Just had my 2010 XF Premium in for it's 45k service at 36k miles (3years) and I have 6mm left on the pads front and back. Seems that driving style and road conditions have a lot to do with wear. I drive 60 miles round trip to my office on the days I am not traveling with a mixture of stop and go and toll road driving. I cannot complain. There is no difference between front and back, although with every other car I have owned the front wear faster (they take the majority of the load when braking - weight transfer, as I am sure everyone knows), thus making this a little odd. Also my tyres are not even close to being worn out. Reports of premature wear of rear pads and rotors, along with prematue tyre wear may have something to do with something other than the car. Maybe the driver?

 

macc24, thanks, I will pull awheel and check before I jump into this, whitbyxf, the car was purchased 12-08 new, wife is primary driver, mainly in town, short trips(80 miles or less) easy on the gas and brakes, replaced tires ataprox 35000, rear rotors/pads aprox 22000, rear pads aprox 40000. The rear pads with 5000 on them are at 3-5mm. I have heard of a few others with results similar to yours, thats why I brought it up She also had a 06 E350, no brake or tire wear with them. its the car

 

Maybe a difference in the model year? Mine is 2010, yours 2009. From your info definitely car related. A quick look seems to indicate 2009s are reporting this issue. Does the dealer have any comments?