Have my 2007 XJ8L in for Oil change service and the dealer is saying it is time for rear brakes. I just did these 16K miles ago. Dealer claims that is about how long the rear pads last. Does this sound right to you? How many miles should you get on a set of pads?

 

Sounds odd. My 04 XJ8 has 55,000 miles and I replaced the rears for the first time at 50,000. There was still a lot of meat left on the pads but I had a bit of high speed braking roughness that I wanted to eliminate.

 

From my experience 16k was about average. The brake setup changed in 2006 (XJ and S-type) and provided more bias to the rear. What I did notice was that the lighter driven cars were wearing the rear brakes more. Harder driven cars the wear was more even front to rear. I have seen them as low as 10k and as high as 20k. It does suck to wear the rears out so quickly. The fronts don't wear near that fast!

 

At that low of mileage, do the rotors have to be replaced or just the pads?

 

Really its preference. My theory on it is there is a better possibility of noise if the rotors are reused. As long as I work at a dealer, I will sell the set. Now, I have replaced just pads and have not had a problem. I do personally think that since those brakes wear out faster than expected, then a pad swap is fine. If the rotors are under spec for being thin, then they need to be replaced. Safety is a concern there. As long as they are still thick enough, then pads should be fine.

 

I also have had to replace rear pads and discs but don't know miles since last time, as I bought the car in May 2010, but the dealer who did the job told me the rears lasted less well than the fronts these days, possibly due to the electric handbrake, or the traction control.

Limited slip diffs are no longer used nowadays; instead the traction control system brakes the slipping wheel, so brakes are used far more on the rears than the fronts, especially for those driver doing "wheel-spin" starts all the time.

 

I'm getting about 20K per set my 07 xjr...fronts were over 60K before I had to replace them and the rotors. I don't think it's anything to get alarmed about.

 

I had my car into the dealer and was advised I needed pads to the tune of $800.00 for two wheels. I respectfully said no thanks and bought a set of Akebono ceramic pads for $80 on RockAuto and installed myself. I have XJR with Brembo brakes and the pad swap took 10 minutes each wheel and the rotors were smooth as can be. Oh and by the way the pads I removed still had 50% material left on them. Another example of a Jag dealer trying to rip off an unsuspecting customer. Buyer beware!!

 

Our rears lasted about 16-17k as well. I attributed it to traction control in the snow. Odd that it seems to be the same in warmer climates.

 

Did that include rotors? Genuine Brembos are expensive.

 

Like a typical dealer, they just said they would do the brake job. The rotors were in perfect condition when I replaced the pads with the Akebonos. Besides saving 700 bucks I no longer have to clean the wheels every two days from all the brake dust.

 

I have a noise (sort of like when the pads are getting thin) when I apple the brakes after the car has sat for a week or so. (2005 XJ 8L)

After a few brakings, the noise goes away.

All braking is normal, but the noise is a concern.

Any ideas?

 

any idea what the rotor thickness needs to measure to be at spec?

 

Sir you completely Nailed it! Excellent answer. I never thought of that!

 

Is the short rear brake life the same for XJRs and Brembo brakes as well? sevice history on my XJR indicates much better brake life. Perhaps that was the previous driver??

 

Probably. A helluva lot depends on driver style. There are the slow-easy-'n-comfortable types (like me), and the wheel-spin to wheel lock brigade.

 

Rust on the rotors?

 

sounds like a little rust on the rotors. You can look at them before driving the car when it has not been used for awhile. If you can see rust on the rotors, its nothing to worry about. It could also be a little dirt. As long as it goes away, after a few brake applications, I would not be concerned

 

Thanks ryejag and to all who replied. I'll keep a good eye on it......

 

2008 XJR. I had 17,000 on rears when pads were almost gone. I do some but not a lot of winter driving. Ditto for spinning wheels.

I recently replaced Pirelli P6, a tire with no know merit and very noisy after 15,000 miles, with Bridgestone Potenza RE970AS Pole Position (who names these things? What do they smoke/shoot/drink?) which are unbelievably good in the wet.

The car is and has always been more responsive to the throttle with stability control off under all circumstances. Since getting new rear brakes and tires I always turn off stability control and will only use it when there is ice, snow, or very cold roads.

As always YMMV.