When do we need to replace rotors?

**crack** · 12-31-2007 06:52 PM

I was wondering if we really need to replace those rotors as recommended by the dealership. I understand that brake pads need to get replaced from time on but do rotors need to be replaced also? I had about 4mm left and my dealership wanted me to replace the rotors and pads. thx!

**Cronogr** · 12-31-2007 07:17 PM

replace the rotors ?? wtf ? the first time i hear that !!

On my b5 i have 150.000khm and i never changed my rotors neither audi told me too (ok ok i change them with betterones but not because of the dealership :P)

**07-Aythree** · 12-31-2007 07:22 PM

you change them when they are below factory specifications. however, you DO NOT turn or machine rotors on most german cars.

**80sGuy** · 12-31-2007 07:45 PM

The answer is: Yes, you do need to change them, but not as often as pads and usually on the front.

Depending on your driving conditions, they can be warped due to extreme heat - say you live out in the California desert, or around the southwest like southern California, Nevada, Arizona or if you drive/brake like a mad manic all the time...then the answer is a definite yes, but you don't need to change them as often times as the pads. They should get at least 85,000-90,000 miles on them under normal wear, if not, more.
If you want better heat dissipation, you should upgrade to some 'cross-drilled' type discs - like Brembo.

**kwan** · 12-31-2007 07:46 PM

Originally Posted by crack

I was wondering if we really need to replace those rotors as recommended by the dealership. I understand that brake pads need to get replaced from time on but do rotors need to be replaced also? I had about 4mm left and my dealership wanted me to replace the rotors and pads. thx!

Ask for the measurement of the rotor. Rotors are replaced when they are within .50mm of the wear limit.

**hmmd** · 12-31-2007 08:04 PM

the dealership replaced my front rotors at the 35k service

**FlyPenFly** · 12-31-2007 08:06 PM

On heavy German cars, I've seen it usually around 40 to 60k miles that front rotors need to be replaced. Easy enough to do yourself and flush the brakes as well.

**Sanjman** · 12-31-2007 09:04 PM

Originally Posted by 80sGuy

The answer is: Yes, you do need to change them, but not as often as pads and usually on the front.

Depending on your driving conditions, they can be warped due to extreme heat - say you live out in the California desert, or around the southwest like southern California, Nevada, Arizona or if you drive/brake like a mad manic all the time...then the answer is a definite yes, but you don't need to change them as often times as the pads. They should get at least 85,000-90,000 miles on them under normal wear, if not, more.
If you want better heat dissipation, you should upgrade to some 'cross-drilled' type discs - like Brembo.

Really? I thought it was the other way around where you live in cold areas with snow/rain that cause the warped rotors. I thought this because whenever you cool down really hot metals too quick causes the metal to warp.

I could be wrong... I failed Thermodynamics class

**80sGuy** · 01-01-2008 03:06 AM

Originally Posted by Sanjman

Really? I thought it was the other way around where you live in cold areas with snow/rain that cause the warped rotors. I thought this because whenever you cool down really hot metals too quick causes the metal to warp.

I could be wrong... I failed Thermodynamics class

No dude, your rotors can only 'warp' under extreme heat conditions. In cold areas, metal becomes 'brittle' when temps drop thus can break or crack when extreme heat comes to play or vice versa, but not warp.
Twenty years ago - when I was young, dumb and full of cum, I literally crack broke the engine block from an old Chevy on very cold mornings by revving it full throttle during start ups. Somehow the heat from the combustion got to the colder layer of the block. This was when engines weren't made of aluminum like today.

Also, I've already went through three sets of front rotors on a Japanese subcompact and the thing's only got 120,000 miles on it. It's a front drive, front disc/rear drum type of vehicle where all the 'load' comes to the front.
In southern California, we get more heat than cold weather.

**element256** · 01-01-2008 11:23 AM

I got the hookup on rotors if you want to upgrade or even for the OEM ones.

**OceanBlueB7** · 01-03-2008 03:00 PM

I picked up my car with 16k miles on it and the rotors were already severely worn. THe pads have yet to reach the wear sensors. Either the pads are too aggressive, or the rotor metallurgy on our cars sucks.