Minimum Rotor Thickness

[fgb59h]

Recently I replaced the front brake pads and rotors on a 99 Camry 4-cyl on the advice of an independent shop. The pads were clearly worn out but the rotors looked ok. I used Wagner BD125222. I had last replaced the rotors about 3 years / 55k miles ago (mostly highway) and the rotars had a "Lifetime Warranty". The mechanic was adamant that they could not be turned so I would like to take them to the store to claim my warranty.

What is the definition of minimum thickness? I read somewhere that the minimun thickness is stamped on the hub bit there is nothing on my rotors. I also recall reading somewhere that Toyota rotors come with a 25 mm thickness and 23 mm is considered minimum. Does that apply to non-Toyota rotors as well?

[Rattlin_Steele]

Original thickness for 99 Camry front disc is 28mm, minimum is 26mm.

[fgb59h]

Do you know if it varies by rotor manufacturer?

[Rattlin_Steele]

Sorry, I don't. But I would be surprised if it does vary. You would think aftermarket manufacturers would have to comply with the same spec.

[CWH5]

Indeed they do as the min spec from the OEM is the standard for inspections.

[fenixus]

wait ... he says rotors cannot be turned because they are (3yr/55k miles old) too ... thin? thinner than OEM minimum spec? or rather warped ?
rotors do not get very much thinner by using them, so either you got a resurfaced rotors in first place or something is not right with your brakes (rotors warping may indicate that) or they were very poor quality ... or you used some kevlar pads on them ... or mechanic is shady ...

i think all of them should have a minimum thickness cast on metal somewhere....

[fenixus]

BTW, on both yotas i'm still on original rotors:
a) 2000 solara, at 79k miles, front rotors original, not even turned, all good (maybe not perfect, but VERY good still).
b) 2002 solara at 124k miles, front & rear rotors original, resurfaced about 30k miles ago, show some signs of warping (slightly uneven braking).

for both cars I will be getting Brembo plain/blank rotors when needed or when replacing pads (in Spring on '02 solara, this car has a neglected brake system).

[fgb59h]

The old rotors were not warped. I personally bought them new, boxed from a national auto parts chain. The new rotors are already in place (call me very risk-averse when it comes to brakes). What I am trying to do is claim my rights under the "lifetime warranty" for the old rotors and have something objective as opposed to "my service person said that the old rotors were too thin to be turned).

I have looked very carefully, cleaned the dirt, etc. The minimum thickness isn't stamped anaywhere.

[TedL]

You haven't said why they need to be turned.......

Personally, I haven't turned a rotor in the last 20 years, and never expect to again. The reason to turn used to be warping, but a turned (now thinner) rotor will only warp faster.

Current rotors are so thin already (to save weight for mpg) that they're not really candidates for cutting. They're also so inexpensive. And then there's the corrosion issue up here in the rust belt.......

[fgb59h]

According to the person who checked the brakes, the rotors were too thin. I assumed he meant too thin to be turned but he may also have meant they were below min thickness.

I checked the old rotor and the thickness is 25 mm. The question I am trying to answer: is 25 mm a safe thickness for a Wagner BD125222 rotor? How do I tell objectively?

[Rattlin_Steele]

The Toyota specification sets the minimum (26mm). If Wagner produces a rotor that is less than that new, then it doesn't meet the spec right out of the box. In other words, its not up to the aftermarket producer, it's up to Toyota.

So, your Wagner rotor at 25mm is too thin. The problem I see in claiming any warranty is how do you prove you didn't have them turned and that's why they're now too thin. Furthermore, even if they honor your warranty, the store is likely going to hand you a new one. So I'll guess you'll have a spare for next time.

[TedL]

Originally Posted by fgb59h

I checked the old rotor and the thickness is 25 mm. The question I am trying to answer: is 25 mm a safe thickness for a Wagner BD125222 rotor? How do I tell objectively?

You were given the answer in post #5. Was it not to your liking, so you're looking for a different one?????????????????

[ajkalian]

True enough the specs for the front rotors are 26mm-28mm, and no shop will turn anything under that spec. But if you think about it, the 26mm spec has to have a bit of wiggle room in it. I mean Toyota probably was conservative in setting the range. If you look at the rotors they are plenty thick, but some engineer put a pencil to it and had to come up with something, so 26mm-28mm was it.

Now if you measure the brake pads they are maybe 3/8" thick, or 8mm. Toyota says that the minimum brake pad thickness is 1mm, so that's 7mm of wear on each pad, or a total of 14mm that the brakes, and components can safely handle.

So using a brake rotor that is 25mm rather than 26mm won't affect how the system works or doesn't work. There is plenty of travel in the pistons to handle the thinner rotors. Now the only question is if Wagner engineered the rotors properly. If they scrimped on the thick part and left the cooling ribs as stock, then the rotors would be inferior. But maybe they made the cooling fins thinner, and the solid part thicker.

But it is true that a stock rotor is 28mm when new, and if the Wagner did in fact come in at 25mm new, the the 3mm would equate to a 10% difference in thickness, and that might be considered significant.

I wouldn't freak out if my rotors were 25mm. But if my pads were only 1mm thick, and I had 25mm rotors, you would be pushing the limits of the system. But if I were to replace the rotors, I'd get a set that started out at 28mm, not 25mm.


.

[fenixus]

just get new Brembo blank rotors at like $40/each and forget the Wagner crap thing. get the in-warranty replacement if you like and if approved keep them on the shelf or sell them on ebay. if they really come as 25mm thick new then they do NOT meet the OE specs, crap.

[fgb59h]

Thanks to everyone for your information. The store clerk looked up his computer and told me that the minimum thickness is 1.06 in (which works out to 26.9 mm). He even showed me the screen. I told him that Toyota's recommended minimum is 26 mm but he would not budge from what his system told him. Net result: No warranty replacement.

What really surprised me was that he agreed to do a warranty replacement for the brake pads which were almost worn to the metal!