Brakes question...
 

I'm thinking of doing a brake job on my XK8. I've noticed that usually when someone has posted the procedure they change the rotors as well. My rotors look to be fine. Is the rotor change a must??

The short answer is 'no'. Then comes the 'but'.......

Assessment of disc (rotor) condition should include:

1. thickness (discs wear through friction with the pads)
2. corrosion (rust on the rim is regular but surface pitting indicates a problem)
3. distortion (pushes pads back meaning further pedal travel to apply brakes)
4. uneven wear (on an individual disk or between axle pairs)

If the disc surface isn't flat, the pad can't contact the full surface area and braking efficiency is reduced. Always replace discs as an axle set, never just one side.

When checking discs and pads, you should also inspect calipers for freedom of piston movement, damaged seals or corroded pistons.

As a guide only, I generally replace discs every three to four pad changes. Think safety and, if in doubt, replace. If you're just not sure then post some photos.

Graham

You didn't mention how many miles are on the car or past brake maintenance.

FYI: I replaced my rotors, calipers, and pads shortly after I bought mine....but the rotors were heavily worn and should have been replaced a long time before. That was about 103K I think. I upgraded to drilled totors, better calipers, and ceramic pads. I love 'em.

oldjaglover,

Which brand of components did you use.

I'm getting ready to change pads and rotors - probably EBC drilled and slotted plus EBC Redstuff pads. I don't think I need new calipers.

I have an '05 XK8 with 85K miles. OEM brakes have always seemed a bit soft to me.

Thanks for the additional information.

John

I'm usually quite obsessive about keeping receipts but I can't find the one for the rotors. I think they are the EBC's like you mention, and the calipers i got from a local parts store after a lot of searching. They cost about $100 each, so not too much, and I can't find the receipt for the pads either. I suspect they got buried in the pile of AllData pages. Anyway, I'm very happy with the setup....and it didn't bust my wallet.

I just bought the car. and noticed a slight (occasional) squeaking of the right rear brakes. No idea when they where last changed. Haven't even visually inspected them just yet. Thanks very much for the advise!

Many professional mechanics will automatically replace rotors because they don't want any repair "come backs." They just don't want any hassles. And, the rotor sales bring in additional profit--with the customer paying dearly.

My original brakes lasted 59K, and my rotors were resurfaced. The machine shop said they had one turn in them, and would need replaced next time. The micrometer tells the truth.

Rotors usually last a very long time, through several pad changes. Check their thickness.

I usually resurface my rotors on my friend's shops machine, just because they do tend to naturally warp and wear unevenly. Should cost you just a few bucks if you bring them in yourself!

Thanks guys