Jim Grant's Tech Tips
'00 Toyota Tundra, Brake Shimmy
Q: I've installed new front brake pads & rotors, brake shoes and drums on a '00 Toyota Tundra. When the brakes are applied there is still a bad shimmy in the truck. It feels like the whole truck shimmies but not the steering wheel. It also has new tires and they have been balanced twice.
- Gary S.
A: You've got a brake problem; I know you've replaced all of those parts, but that is not a guaranty that the parts you installed were good. Or there is another underlying problem causing the shake when braking. The first step is to insolate the braking system to determine if the rear brakes or the front brakes are the source of the shake. Once you've found which end of the vehicle's braking system is causing the shake you have to isolate each wheel. I've had brand new brake rotors and brake drums that were warped or had excessive run-out right out of the box. That is why you have to take the time to isolate just from which brake the shake is being caused by. Once you figure out which wheel brake rotor or drum may be the problem don't go right to the parts store yet for a replacement. Inspect the mounting surface that the rotor and/or brake drum set on. There can be no rust. All it takes is one flake of rust between the mounting surface and the new brake drum or rotor to cause a good amount of run-out, resulting in a shake when braking. If the mounting surface is clean and free of rust then it should be checked to be sure that the mounting surface is not damaged. I've seen some guys that think they're Thor the God of Thunder and have brought their mighty hammer down to remove rusted or stubborn brake rotors and drums. What Thor doesn't realize is that the mighty hammer can cause more damage than good when swung in a godly manner. So if the vehicle started to brake shake after the brake work, it is likely that you have a defective or damaged brake drum or rotor. If the shake is the same as before the brake work was performed, be on the look-out for damage cause by the God of Thunder.