Well, in over 60 years of driving/owning many vehicles I have never had a brake rotor issue (except one time on a ZX11 mc which was my fault).

I drive fast (too fast) but;

When I purchased this XK some years ago I put new Centric high carbon rotors on it and they were fine for 11K miles +/-. I replaced them with Brembo units…they were good for 10K miles. I’m installing new Centric high carbon units again this weekend.




I think that my suspension is worn enough that any slight rotor irregularity (I’m afraid to start the warp no warp argument) is enough to start this pulsing when braking lightly. To that end I have several new front end pieces that I’ll install over the next month or so with hopes this mitigates the issue...

Any thoughts on this other than to change my driving style?



wj

 

I drive like a fool myself, and rotors usually last me 40-50k miles.

 

xk vs xkr?
I know I was asking too much from the suspension until I replaced xk struts with xkr...now I'm satisfied.
I've been much harder on other vehicles...shoot even my xk100's rotors have never given me a problem.
wj

 

When I upgraded the brakes on my XK, I went with drilled & slotted Cquence rotors (out of Calif.) and Akebono Euro premium ceramic pads. I was very satisfied with the product and customer service from Cquence. They machine the rotors to your spec, so they are at least partially US made (machined). And unlike some other drilled/slotted rotors that have opposite direction on each side, Cquence machines right and left side directionally correct. Very reasonably priced too.
Just a suggestion.

 

Depending on how long these stay true I may need to look elsewhere (or maybe my dream xkr will show before then).
I'm still using the pads I purchased with the first set of rotors...they show little wear, maybe they are the culprit.
wj

 

I’ve always heard, and found, that pads wear faster than rotors. So it’s surprising you’re experiencing the opposite.
Might want to check to see what those pads are made of.

 

Or are the pads too hard? Or is there significant pad material on the disc, or…

FWIW, I get 50 out of factory options.

 

Years ago when my original rotors were driving me crazy with excess vibration at freeway speeds when slowing down, I asked my mechanic, who services about 10 of my family's cars to find me replacement rotors. He was used to getting them from a local source in the San Fernando Valley. He got a set for my car, put them on, and after one day of driving with them, I told him they were terrible and that I did not want them on my car. I went shopping for new rotors myself and found some drilled and slotted rotors from a company in Southern California called R1 Concepts. I called them, asked some questions, and the person I spoke with was knowledgeable about their products and he provided excellent service over the phone. I ordered a set for all four wheels. I just looked up when I bought them and it was six years and at least 100,000 miles ago, and they're still smooth as silk and still look terrific. I I can't remember the specific name of the ones I ordered, but they were quite reasonably priced, shipped promptly and the company provided excellent service. They've been on the track many times and in checking their website a minute ago, they have several different choices for our cars with recommendations based upon what kind of driving you'll be doing. I know I've read some negative comments on the forum regarding the experience a few others have had, but I have 220,000 miles on my XKR, and these have been the longest lasting, smoothest operating rotors I've ever owned on any car in my 56 years of driving. I believe this picture is the set I bought from them long ago.

 

When you change them check the mating surfaces on the hubs and the wheels are dead clean. Unevenness on the wheel mating surface is capable of pulling the hub and rotor (disc) out of true just as much as a mucky hub when the wheel lugs are torqued up as the wheel centres are very stiff.

I discovered this on my XK as the wheels had been repainted without masking the mounting surface. A dial guage test indicated a new rotor to spin true without the wheel, or the wheel lightly attached. The new rotor became warped when the lugs were tightened, flat when untightened. Stripping the paint off the mating surface rectified this problem.

I discussed this with a mechanic friend who informed me that the brake calipers were able to accommodate a warped rotor by moving slightly but after thousands of miles they will start causing pulsed braking.

The brake pulsing problem is caused by the rotor wearing unevenly. The brake pads make light contact with the rotor all the time and gradually wear the surface even if the brakes are not applied. On a warped rotor the high areas become worn down more than the low areas during non-braking driving resulting in the pads experiencing "squeeze, relax, squeeze, relax" on every wheel rotation as when the brake is applied.

I was initially surprised the uneven wheel surface made such a difference but considering how thick the wheel centres are they are probably stiff enough to slightly distort the hub and rotor.

Hope this explanation helps.

 

If I need to go through this another time (10k miles), I will check them out. Thanks
WJ

 

It does and I"ll check everything closely...thankyou
wj

 

One good thing about replacing rotors all of the time, the fasteners come out easily!
I took my time and all told it took 2 hours to complete.
The brake pads still look very good, I block sanded them and reinstalled.
No more pulsing for a while!
Happy times...the sun is out and it's 80(f)...top down while seating the pads, woohoo.
wj