02 Tundra Brakes

toyota
brakes
tundra

#1

Hi Guys, I absolutely love your show and have a good laugh almost every time.



I am at the end of my experties now with this trucks braking problem. I know this truck was build with brakes not quite big enough so i did the brake upgrade according to the TSB about 2 years ago. The warping never actually went way.



Now here is the problem, I can never get the front wheels to lock up or the ABS to activate under hard braking loads. I have no CEL or error codes or ABS lights and last night I upgraded from OEM pads and rotors to Power slot Cryo treated rotors and Hawk LTS pads and I still cannot get the trucks wheels to lock up. Is this normal operation and to be expected with the tire surface and truck weight combination in contact with the road or should I be concerned about this?



I would really like your advice. My wife and I had our forst son 3 months ago and I need to know if they are safe in this truck?



Kind regards




#2

The most important data involving braking is stopping distance. The fact that the truck does not engage the ABS (if it has a working ABS, the brakes won’t lock up, period. You will engage the ABS or not).
I think you gave this truck more braking ability than is normal and that the ABS was designed to accomodate the undersized brakes. How does the truck react to hard braking, aside from the fact that you are unable to make the wheels lock up (not something you want to happen anyway). Does it stop straight and fast without locking up or does it just feel soft and eventually stop?
If it is the latter, the problem is hydraulic pressure. You increased the volume of the brake components but the pressure exerted on the pads has not increased. You would never engage the ABS or (minus the ABS) ever lock up the brakes in a hard brake if the hydraulic pressure was insufficient versus the area of rotor and pad.
The question is whether or not the actual stopping distances have increased. There is no value in locking up in a hard braking situation. You lose steering, first of all, and the stopping distance becomes reliant on road conditions (wet, oily, sandy, crumbling and old versus dry, clean and fresh).
Maybe you can modify the master cylinder to accomodate your oversized (or right-sized) brakes?


#3

It’s actually pretty hard to get disc brakes to lock up (or activate the ABS) on dry pavement. You have sufficient front end weight (and total weight) on that truck that the rubber is really digging into the pavement, and ABS won’t activate unless the wheel actually does stop turning (start skidding). Assuming you’re not having difficulty stopping, I don’t see anything in your post that would be abnormal except “the warping never actually went away”. That condition I’d look into more deeply.

Drum brakes of old actually lock up easier than disc brakes. Drum brakes were typically designed such that the friction of the pads on the drums actually pulled the pads into the drums with more force. It’s called “self actuating”. Disc brake don’t have this tendency. But with any brake, locking up is not a good thing. It adversely affects control.

Now, about that shaking in the steering wheel, have you actually checked the rotors for lateral runout? Have you checked the wheels/tires for smooth operation on a road force balancer? Have you checked your components for wear and/or looseness (tie rod ends, ball joints, etc.)?


#4

Thank you for all the replies. You guys have put my mind at ease… the truck does stop pretty quick if you jump on the pedal and with the new rotor and pads it is even better.

I thought the wheels would lockup or the ABS would activate under big brake loads and it is comforting to have you guys tell me what I thought.

I do have a little shaking as the truck comes to a stop and it cannot be tr rotors for they had 10 miles on them as this happened and the rear drums are still good too so I am thinking it is a wheel balancing issue.

Again thank you for your help guys.


#5

Hi Kizwiki,

You mentioned “Maybe you can modify the master cylinder to accomodate your oversized (or right-sized) brakes?”

how would I do this? would I have to replace the MC or is there a way to alter it?