The brake story: frequent disk warpage

[Lux]

Hi guys.

I am aware of the effects of wheel torque-- and variations thereof-- on the brake disk and hub assembly. I am fairly confident in the torquing of my own wheels (120 Nm) and the accuracy of my torque wrench, being that it was recently calibrated by NIST-traceable equipment. I checked its accuracy on the weekend against my other torque wrenches and they are all consistent: variation within 0.7% or less of each other.



My torque wrench is the Snap-on TQFR250E. My two others that I checked it against are Snap-on ATECH3FR250B and Snap-on ATECH2FR100B.

With that being said, I think we can drop the speculation of improper wheel torque.

Originally Posted by CoryM

Fixes:

- instead of staying on the brakes steady down a hill, release them occasionally. They will cool down a LOT in the second or two you release.
-always come nearly to a stop, and then let your car roll for the last few feet. Let the rotors cool down below the critical temp before sitting there stopped with foot on brake.
-if your rotors are hot, but you still need to hold the vehicle at the light etc, use the park brake for a few seconds. Rear brakes do not get nearly as hot as front and are much less likely to warp.
-make sure your rear brakes are adjusted correctly. Otherwise the fronts end up doing all the work.

Hi CoryM, I still think the disks are unable to cope with the heat and am still considering alternative solutions. Do larger brake calipers and disks from another Toyota car fit on the front? What about the rear disk conversion (using genuine Japanese OE parts)? By the way, I do make sure to bed in the brakes with a increasing-torque regimen after installing them. Additionally, after a high-speed stop, I hold the car with the parking brake in an attempt to prolong the life of the disks and avoid prolonged parking of the hot pads on the same section of disk... although that seems to have been wasted effort because they is still disk warpage.

Kindly

[WeeYari]

Originally Posted by Lux

Do larger brake calipers and disks from another Toyota car fit on the front?

http://www.yarisworld.com/forums/showthread.php?t=36955

[CoryM]

Eesh. Someone else with too much money in torque wrenches (at least mine are different sizes though :þ ).

WeeYari posted a nice link re: bigger front brakes. Re: rear brakes, unless you feel the drums are overheating and fading (causing the fronts to work harder), there is no point upgrading. See attached photo to get an idea just how little the rear brakes do (that's full braking w/ all-seasons). Just make sure the rears are always adjusted correctly. Use a little caution upgrading the fronts as bigger is not always better, and let's be honest, if you are braking hard enough to warp stock rotors you are probably going to brake harder with the larger rotors. My Mother warps rotors regularly. I have tried just about every combination of pads/rotors and even tried racing hardware at one point. End result is now I just throw the cheapest rotors in when she warps them, and use the same pads.

My suggestion to you would be to try another set of OE sized brakes, and install cooling ducts. If you can keep rotors below their critical temp, they will not warp even if you hold foot on brakes at stop etc.

I still think if I can take cars over the Coast Mtns full of camping gear and not warp, you should be able to adjust your driving to not warp brakes in flat Ontario. And I have owned cars that have undersized brakes on them from factory (the Yaris actually has pretty good brakes for what it is).
Cheers.