Brake Service Questions

[Paddy McMahon]

Had my tires rotated & balanced today. Mechanic at tire shop tells me I should be thinking about brake service very soon as there is only 2mm of lining left on the front pads. I was also told that the rotors are generally replaced rather than turned... . this dosen't sound right. I was expecing brake service as I have 75K on the truck, but replacing the rotors sounds unnecessary and expensive. Anyone with some experience on this issue that can share some wisdom?

 

[JHardwick]

I'm at 430,000 miles on the original rotors, they haven't been turned either.

 

[jelag]

My 04 3500 dually went to 160K miles for the first brake job...

My 05 3500 dually is at 75K miles and has 50% left... maybe you should look at your pads your self... .

If they need to be machine we do that... . if and when they get to thin... . there is a stated thickness on the rotor, than we replace them...

 

[Paddy McMahon]

thanks. I did see the pads when the mechanic had the wheels off and they are close to the end of their service life. Perhaps they would have lasted longer if I had installed my cool PRXB sooner! I was more concerned about the comments about the rotor replacement and wanted to confirm that they could be turned as needed until they no longer met the minimum thickness spec's.

 

[JLandry]

Paddy,



I recently did the first front brake job on my truck when I was replacing all the ball joints. The truck has about 97,000 miles on it and the front pads had worn to about 5/16" thick. There was no critical need to replace them with that much friction material left, but since I had everything apart, I figured I might as well do it.



So I took the rotors to a local machine shop to have them turned, and even though they weren't at the minimum thickness yet, they refused to turn them after taking measurements. I have some machining experience myself and was a little confused by this refusal, but they explained to me that after they turned the rotors down smooth, the thickness would be so close (but still above) the minimum thickness that within 20,000 miles or so they'd be under the minimum thickness. They said basically you can thank cost cutting measures for having a rotor manufactured so thin from the beginning that it can't be safely turned and reused unless almost still new.



In the interest of safety I had to reluctantly agree with their logic and I bought replacement rotors. What's another $150 for a pair of rotors when your life could be at stake?



Don't believe the machine shop is right? Keep in mind they had nothing to gain by refusing to turn my rotors... they were just being safety minded.



So possibly this is also why your mechanic suggested that the rotors are usually just replaced.



Best regards,



John L.

 

[p-Bar]

Paddy,

I recently did the first front brake job on my truck when I was replacing all the ball joints. The truck has about 97,000 miles on it and the front pads had worn to about 5/16" thick. There was no critical need to replace them with that much friction material left, but since I had everything apart, I figured I might as well do it.

So I took the rotors to a local machine shop to have them turned, and even though they weren't at the minimum thickness yet, they refused to turn them after taking measurements. I have some machining experience myself and was a little confused by this refusal, but they explained to me that after they turned the rotors down smooth, the thickness would be so close (but still above) the minimum thickness that within 20,000 miles or so they'd be under the minimum thickness. They said basically you can thank cost cutting measures for having a rotor manufactured so thin from the beginning that it can't be safely turned and reused unless almost still new.

In the interest of safety I had to reluctantly agree with their logic and I bought replacement rotors. What's another $150 for a pair of rotors when your life could be at stake?

Don't believe the machine shop is right? Keep in mind they had nothing to gain by refusing to turn my rotors... they were just being safety minded.

So possibly this is also why your mechanic suggested that the rotors are usually just replaced.

Best regards,

John L.

You can thank the trial lawyers for everybody running scared


I just did the brakes on front 2 nd time 78k mi alot of city driving probably could have gotten more out but time constraints had me change them early. I don't turn my rotors since I don't overheat them their is no brake shudder. I didn't "mic" them either still thinking who I could sue if I get in an accident.

 

[Paddy McMahon]

Thanks for the heads up. I am planning on taking the truck to my regular mechanic and getting the brakes done. I felt like the tire shop may have just been advocates for doing a parts swap rather than turning the rotors or checking the spec. I agree about the safety issue and if I am told by my regular mechanic I am better off to sport a new set of rotors that is the path I'll take.

 

[jelag]

JohnL



We turn hundreds of rotors and drums a year, doing most of that work on larger equipment. . I can assure you there is lots of safety margin when the rotors or drums are at min. thickness... .



I would never take the chance with a customers product... but I would never suggest to a customer what was told to you.....



I hope this helps... BTW we've had the same set of standards for the 30 plus years the company has been there... We've not had a problem...

 

[Matt400]

One thing that has not been mentioned-



If you work your brakes hard, especially in the mountains then turning is not a good idea IMO because the rotor will be more susceptible to warping- the thicker it is the better it can dissipate the heat and hold true.



Now, if your rotors are not warped then don't machine or replace as long as you have not damaged them from letting the pads go too far.

 

[Paddy McMahon]

well I ended up w/ new rotors. Mechanic stated that the rotors could have been turned w/ in spec, but they would be barely in spec and would be prone to warpage under use-just liek Matt400 stated. He felt it was in my best interest to go w/ replacemnt rotors so I am out an additional $380, but have peace of mind.