I recently had a slow leak in a rear tire and while it was off the guy said I needed new pads as there was only a mm left. I looked and agreed.

Went to the store bought ceramics pads for all around. Started with the rear ones and found both sides were indeed down to 1mm on one pad and the inside one had 2mm.

Then I got the fronts off and found they still had plenty of pad left. I changed them anyway.

There’s 70k on the truck and the rotors were within spec and I didn’t change them,

So the question is why are the fronts still ok but the backs are worn, when all the weight is up front?

Updated info
2019 F150 extended cab
No towing,
No eco mode driving
The pads have never been changed

This message has been edited. Last edited by: MikeinNC,

What kind of truck? Do you use adaptive cruise control? IIRC, most use the rear brakes for small speed adjustment.
Or, could be the rears are dragging a bit, out of adjustment.

That is a good question, Typically front brakes are going to wear faster, did you happen to notice if there was more brake material on the front pads vs the rear pads?

Probably the electronic stability control and traction control applying rear brake to help handling.

I forget what GM calls it but for years they have had a system on the trucks that electronically makes the back brakes do more work based on load

Did you change the fronts and not the rears at some point?

quote:

Originally posted by trapper189:
Did you change the fronts and not the rears at some point?

This. You can only make a good comparison if you know when each was changed, ideally at the same time if you want a perfect comparison.

I've found that pickup trucks tend to wear faster in the rear than in the front. Keep an eye on them going forward, because aftermarket pads will not get you 70K miles like the OEM will.

quote:

Originally posted by bdylan:
Probably the electronic stability control and traction control applying rear brake to help handling.

Yeah these two along with adaptive cruise can cause brakes to wear out much sooner. I imagine TC engages pretty frequently on a pick up truck.

Brake bias before anti lock systems was toward the front. Bias wasn't as important with anti lock, so proportioning was changed to make normal stops more comfortable with less front squat by the bias being to the rear brakes. That's my perception anyway.

Steering tires probably work best with less braking applied also, as does front suspension compliance.

I just did a quick search. Along with everything that’s already been posted, thinner initial pads contributes as well. I’ve also never seen rear pads anywhere close in size to fronts.

You’d think with the size difference between front and rear pads they’d wear out at the same time. With a 70,000 miles on the original pads, I’m guessing you’re not aggressive on the brakes. Maybe if you brake slowly, less weight gets transferred to the front and the rear brakes do more work than if you brake quickly.

Here on the forum we are encouraged to not copy and paste AI generated answers. But, I have found ChatGPT fairly helpful. I asked your question of AI, and it gave straightforward and believable answers.
1. ABS + Electronic Brake Distribution
2. AdvanceTrac stability control
3. Unloaded and light weight in the rear along with stability control
4. Brake pad size difference (relative wear rates)

Anyway, I think you have done well to replace all four with the same material. This will retain uniform frictional forces for all the advanced electronics to deal with.

^^^It’s like AI read this thread.

quote:

Originally posted by P250UA5:
What kind of truck? Do you use adaptive cruise control? IIRC, most use the rear brakes for small speed adjustment.
Or, could be the rears are dragging a bit, out of adjustment.

This is correct, if your GM has Adaptive cruise control the rear brakes see use to help adjust speed.

In the newer vehicles the backs get more use and the pads are much smaller than they used to be since weight is more balanced. My expedition I think I did rear pads at 55k miles, at 81K miles fronts are still good and I do a good bit of towing.

I bought a used Civic 4 months ago, 43k miles. It needed a rear brake job, front was ok.

I’ve had cars the other way, not that uncommon to have the back or front wear at different levels. I think more so when disc on one axel, drum on the other.

My last two trucks a 14' Tundra and 19' Ram both went through rear brakes first. I thought something must have been wrong as I always thought it was front that did most of the work. I must be the way it is now.

My MINI rear brakes are always worn more than the front, by design.