I have a 2001 L with front and rear disk brakes. Shouldnt I have almost equal brake dust front and rear on my rims just like a car with 4wheel disc's does? Im just curious, i have tons on the front, and not much on the back, what gives?

 

You should have more on the front since your front brakes do over 80% of your stopping.

-Jon

 

Jon,

Why is it that the front brakes do over 80% of the braking? How does that work exactly anyways? J/w..

 

They are suppose to work that way. Your front brakes need to do most of the braking espessially in a truck otherwise you would lock up the back one when you brake hard and the front tilts downward and the back lifts. Yuo don't want to be sliding on the back ones. You brake system will have a proportioning valveso that when you apply the brakes the front ones come on harder than the back.

As a result you will see more brake dust on your front rims than on the back. Yuor front pads will wear out long befrore the back ones.

 

Your engine is the heaviest part of the vehicle and is located in the front of truck. So we use the front brakes to do most of the braking because the front tires get better traction with all the weight on them. The rear brakes lock up very easily because there is nothing to hold the rear tires to the road. Most vehicles have a proportioning valve to adjust how much pressure goes to the front brakes and how much to the rear. Some new trucks like the Totoya Tacoma have a load sensing proportioning bypass valve which adjusts the amount of rear braking depending on how much weight is in the bed. Under normal braking you would probably see around 1,200 PSI in the front brakes and 500 to 700 PSI in the rears.

Old cars had metering valves which sent hydraulic pressure to the front brakes first, then half a second later allowed pressure to go to the rears.

That's the gist of it, it gets more complicated from there with abs, trac control, combination valves, electronic brake control, etc.

-Jon