Hey guys.

I've got pulsing when I brake at low speed (only noticable when coming to a full stop).

I check the rotors and the front 2 are pretty shiny (glazed?) and have light tracks in them, but not major grooves.

I can get them machined, but I would want to try sanding them before to see if that fixes it.

I've read a few articles and my haynes manual and theres no consitant method/data.

Some say 120 grit, some say 1200 grit, some say sand with the rotor, haynes says go in circles and scratch the **** out of them.

- Can anyone advise on the best grit to use/what method?
- Will I need to adjust my pads or anything?

Cheers in advance

 

If you are getting pulsation on the pedal, you most likely have warped rotor(s). You will have to remove them and turn on lathe. Use dial gage to measure how much they are off before you make decision to remove or not. Service manual should have tolerance listed. Usually machine shop or brake shop will do it for you. Make sure you go a reputable shop.

My wife's Mazda was in for tire installation (bought tires from Tire Rack) and the shop said the back rotors are warped and need to turn. If it was my car I would have deferred the work. The shop turned the rotors twice because they were still warped after the first turn. Now since they turned twice, they went under the limit and I ended up buying two new rotors. I really believe the rotors were fine to begin with because I was not feeling anything when I was driving the car to this crooked shop (Tire Rack recommended).

 

x2

i don't see how sanding will help, they're probably warped so you need to get then machined

 

Thanks guys, I'll get them machined.

That being said, is warping due to warn/old/bad pads, will I need to change the current pads, so this doesn't happen again or can I get it machine and leave current pads in?

Cheers

 

Warped rotors are from improper bed in of the pads onto the rotor ive heard that you can reuse the pads but I've personally never done that and wouldn't recommend it, but if you are able to "properly" break them in then go ahead and try.

 

Warping is also likely if the brakes overheat. That could be from very heavy use, "two footed" driving, or mechanical problem that causes them to drag.

Always put new pads on a new or resurfaced rotor. The price of new OEM style rotors is so low it is hardly worth trying to resurface them.

 

Word. $20 per for mine at Autozone.

 

Thanks for the advice so far guys, much appreciated.

Heres the costs for my options:

- $70 for maching of old rotors (done at my local Brake & Clutch)
- $300 for machining and new pads (done at my local Brake & Clutch)

- $45 for pair of new pads (bought at local auto store)
- $120 for pair of new rotors (bought at local auto store)

Looks like it would work out considerably cheaper to just get a set of new rotors and pads. If I were to go that way, would I need anything or should I replace anything while I'm at it?