Sticky pin = warped rotor?

[tjxtreme]

I had warped front rotors about 50k ago, got them replaced, and it was gone. Now it is back, and particularly noticable at highway speeds (through the steering wheel and brake pedal). I took the fr. wheels off, and inspected the brakes... all I could find that was wrong was a broken boot on a caliper slide pin. I live on a sandy road, and all kinds of sand was in there...etc. So, I cleaned and lubed it for now and will get a new boot (if possible).

 

What next, Could this be the cause of the warping or should I look somewhere else?

Should I get the rotor machined or get a new one? brand?

Can I replace one side and not the other?

The pads are still thick and evenly worn... do I need to replace them too?

 

Thanks, Andrew

[ampsucker]

I had warped front rotors about 50k ago, got them replaced, and it was gone. Now it is back, and particularly noticable at highway speeds (through the steering wheel and brake pedal). I took the fr. wheels off, and inspected the brakes... all I could find that was wrong was a broken boot on a caliper slide pin. I live on a sandy road, and all kinds of sand was in there...etc. So, I cleaned and lubed it for now and will get a new boot (if possible).

 

What next, Could this be the cause of the warping or should I look somewhere else?

Should I get the rotor machined or get a new one? brand?

Can I replace one side and not the other?

The pads are still thick and evenly worn... do I need to replace them too?

 

Thanks, Andrew

 

yes, replace the boot and make sure you get plenty of the correct type of brake lube in and around the pin when the rubber is on.

 

here's what i think is causing your "warped rotor" vibration. i think the stuck pad(s) is (are) heating up causing the pad glue to partially liquify. when you stop or park, the pad is leaving a slight imprint of glue on the stopped rotor causing a rough spot. i think if you get the caliper working right again, you should be able to rebed the pads by doing some semi-agressive breaking to slough off the stuck on material. if that doesn't work, i would try cleaning the rotor with some steel wool or a mildly abrasive pad (both inner and outer surfaces). resurfacing would work too if it's bad, but that removes metal causing you to have less mass on the rotor.

 

if you don't have any grooves and plenty of pad material left, i would try to salvage what you have. if these simple steps don't work, you can always ramp up the efforts with new pads, rotors, etc..

[RallyKeith]

Sticking pin would cause the pads to stay engaged, causing the rotor to build up a ton of heat. This could easily cause the warped rotors. I would try turning the rotors first if they were new not long ago, but you should always do everything with brakes in pairs. If you turn one, you ned to turn the other.

 

Keith

[idosubaru]

first - did the same one warp both times?

 

yes, sticking calipers often cause warped rotors - either the parking brake mechanism sticks (on older soobs where the e-brake is up front) or the caliper itself sticks, which is most likely on your newer generation. if it's isolated to one side and you'd rather not replace both, you are fine to replace just one. the pads/calipers seat to the rotor, they don't care nor does the brake system have any way of "knowing" that one rotor is a millimeter thicker than the other. the pads/calipers will seat accordingly.

 

also - what rotors did you use, cheap-o aftermarket rotors may be lower quality and easier to warp as well, i've seen them warped out of the box.

 

i would guess replacing the boot and greasing it should prevent future problems.

[tjxtreme]

Thanks... I'm not sure if it was the same one, because I had both front ones replaced last time at a "Brakes Plus," Or rather "Brakes Minus"... that was a terrible joke, they should ban stuff like this from the message board.

 

This time, now that I am more knowledgable, I checked them myself and found what those guys probably neglected to tell me about. I'll try the sticky pad theory first, then probably just replace if that doesn't do it. Are there any respectable aftermarket brands, or is OEM the only way to go?