Concentric grooves on rear rotors: 2002 S60 2.4T AWD 140K km

Post by **kdaide** » 27 Jul 2007, 12:13

I have concentric grooves on both my rear rotors. Is this a sign that my brakes are seizing up? There is no noise or noticable friction. It looks like I need to replace the rotors but don't want to put new ones on and have it happen again. What could be causing these grooves? BTW: The pads are grooved as well?

What are the tell tales signs of brakes seizeing up?

2002 S60 2.4T AWD 140,000 km

Post by **JRL** » 27 Jul 2007, 15:24

Not really, most have the grooves after some miles.
Doesn't mean they're bad at all
HOWEVER:
If these are original, I would bet the farm they need replacing.
Probably under the minimum depth

Post by **kdaide** » 27 Jul 2007, 15:28

JRL,

The groove are about 1mm deep which makes the rotor rough to the touch. The front rotors are nice and smooth and shiny.

Could rust "chips" cause this? If my brakes where seizing, what would be the signs?

Post by **kdaide** » 27 Jul 2007, 15:29

These are the original rotors but I drive a lot of highway miles.

Post by **meine39** » 27 Jul 2007, 18:06

Siezed calipers would usually cause noticeable noise and/or vibration - complete seizure and the car wouldn't move.

If you've got a noticably rough finish on the rotors, its time for new ones. Volvo considers brake rotors 'consumables' (like tires and batteries) that need to be replaced. If the rotors on your car are like those on my 850, they are alarmingly thin, even when new. The rust you are seeing is common on old rotors - they are cast iron (the rotor surface remain shiny because of the contact with the pads). The rust is probably not casuing the wear you are seeing.

A mechanic can measure your rotors for thickness and runout and tell you if they need to be replaced. New rotors should always be installed with new pads.

Post by **JRL** » 27 Jul 2007, 18:11

meine39 wrote:Siezed calipers would usually cause noticeable noise and/or vibration - complete seizure and the car wouldn't move.

If you've got a noticably rough finish on the rotors, its time for new ones. .

I will repeat.
Many Volvos get these grooves on the rotors.
As long as they're thick enough, they're ok... BUT...not if you're installing new pads, THEN you have to install new rotors