Measuring rotor thickness WITHOUT taking off wheel?
Thread Starter
Senior Member
Joined: Nov 2013
Posts: 323
Likes: 4
From: Los Angeles, CA. USA
2013 c250
Measuring rotor thickness WITHOUT taking off wheel?
I'm going for the Akebono front brake pads since I got the "brake pads worn. Visit workshop" on the dash. I know what rotors to get, but I don't wanna get em if the minimum thickness is still there, so is there a way to measure my rotors now w/o jacking up the car, taking off the wheels, blah blah? Same for the rear rotors. I hear I measure in several places, especially the outside lip. Any other pointers?
Thanks!
Thanks!
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Joined: Jan 2005
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From: Orange County
2005 C Wagon (No snickering please!)
You need to remove the wheels to measure the rotor thickness. You must read several positions from inside the friction surface to the outside. You don't read the outside lip because the pad does not touch that part.
The tool needed to read the thickness requires precision to get a meaningful reading. It is a deep throat micrometer. Here are eight examples of those typically used in the automotive trade.
http://www.starrett.com/metrology/me...ortBy=none/asc
Using a standard micrometer or calipers is worthless. It is a serious safety problem to run rotors that are too thin. If you cannot measure the thickness properly, just get new rotors. Factory rotors are good for two sets of pads as a general rule.
The tool needed to read the thickness requires precision to get a meaningful reading. It is a deep throat micrometer. Here are eight examples of those typically used in the automotive trade.
http://www.starrett.com/metrology/me...ortBy=none/asc
Using a standard micrometer or calipers is worthless. It is a serious safety problem to run rotors that are too thin. If you cannot measure the thickness properly, just get new rotors. Factory rotors are good for two sets of pads as a general rule.
Thread Starter
Senior Member
Joined: Nov 2013
Posts: 323
Likes: 4
From: Los Angeles, CA. USA
2013 c250
Thanks Movie!
Problem is, even if I fight off my cheapness and get front rotors without measuring, how do I know the back ones don't need replacing too? I don't, which means I'd need to replace the pads and rotors in the back and that my cheapness cannot stand.
I've found some $50-$80 digital micrometers that measure b/w .300 to 1.300 inches. What do you think of the one below? And could I use this to measure the back brake pad as well since there's no sensor to tell me whether it even needs replacing?
Thx,
http://www.autozone.com/autozone/acc...er=186497_0_0_
Problem is, even if I fight off my cheapness and get front rotors without measuring, how do I know the back ones don't need replacing too? I don't, which means I'd need to replace the pads and rotors in the back and that my cheapness cannot stand.
I've found some $50-$80 digital micrometers that measure b/w .300 to 1.300 inches. What do you think of the one below? And could I use this to measure the back brake pad as well since there's no sensor to tell me whether it even needs replacing?
Thx,
http://www.autozone.com/autozone/acc...er=186497_0_0_
Super Member
Joined: Mar 2012
Posts: 968
Likes: 62
From: San Francisco, CA
2005 c230SS
For $80 why don't you just buy yourself a new pair of rotors? 
Seriously with the amount of money you're saving DIY, if you're doing brakes every two years I would suggest replace the rotors along with it and save the hassle of potential problems during your use of the second set of pads.
Seriously with the amount of money you're saving DIY, if you're doing brakes every two years I would suggest replace the rotors along with it and save the hassle of potential problems during your use of the second set of pads.
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Joined: Jan 2005
Posts: 2,848
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From: Orange County
2005 C Wagon (No snickering please!)
The KD tool looks like a real bargain at 18! The AZ tool would work also. The mic should work fine for front or rear. Probably better to buy a metric unit so you don't need to convert units. Math errors are so easy to do.
Rock Auto sells some good things, but $13 rotors are something you should only consider for a car you are selling. If you keep the car you will have the aroma of rice every time you step on the brake.
Rock Auto sells some good things, but $13 rotors are something you should only consider for a car you are selling. If you keep the car you will have the aroma of rice every time you step on the brake.
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From: So. Oregon Coast
C230 Sport Coup + 2006 W164 ML350 + 99 Ford Escort RIP
If you go with Akebono's get new rotors.
You don't want the rotors to wear out before the pads.
Those pads last nearly forever.
Still waiting for mine to wear out, 130K miles on them....
the car will collapse around them, and they still be there.
You don't want the rotors to wear out before the pads.
Those pads last nearly forever.
Still waiting for mine to wear out, 130K miles on them....
the car will collapse around them, and they still be there.
