Rear brake bias - wearing rear pads VERY fast

Hi all,

Looking to see if you can help me identify why I'm wearing my rear brakes VERY fast on my 2006 4Runner. After about 10K, my pads are better than half worn, probably closer to 2/3.

Replaced rotors, pads, and calipers all the way around, a little over a year and 10K miles ago. I used Napa parts and selected their more "premium" option for the pads and rotors specifically ("Silentguard" pads). I also flushed the brake fluid out all the way around. When I got done, the pedal felt stiff, but I attributed that to the fact that the old components, including the calipers, were shot after 240K miles. I have a couple of 5th gens as well, and every time I'd jump back in to the 4th gen, it would take some time to get used to the brakes so I wasn't lurching forward when stopping.

Now 10K miles later, the rears are worn. Equally on both sides, and equally on the inboard and outboard pads. I'm also feeling pulsation and noticing the front rotors don't look as smooth as I'd expect. I suspect I've got a rear bias on braking for some reason.

I'm going to tear into it tomorrow, but I'd appreciate any thoughts for things I should be looking for beyond sticky calipers or poor quality pads. Anything in particular that could cause the rear brake bias and accelerated wear?

Yaw sensor doesn't affect the brake bias, does it?



Thanks!

 

Verify the rear caliper pistons can be pushed back in fairly easily. My right rear caliper ground down the pads to nothing because the piston wouldn't retract without lots of force.

 

I'm having a similar rear bias on my 5th gen. New pads all around and the rears wore out first with the fronts at almost 90%. New rears and they are still wearing faster than the front. Good news my fronts will last forever, bad news my rears will need to be replaced 2x as fast.

Will be going to my Toyota specialist for an oil change soon, will have him check it out.

 

I read some time ago that 5th Gen brakes are biased to the rear by design. I replaced the rear pads on my 2019 at around 90k miles, and fronts around 115k.

 

I've always had the 4th and 5th gen rears wear quicker than the front (usually need a rear replacement about 15-20K miles sooner than the front), but I've been used to at least 45-50K out of the rears and 50-65K out of the front. 10-15K from the rears like I'm estimating now is waaaay too soon.

Please let me know if you get any info from your mechanic. Thanks.

 

Thanks. Same as note above:
I've always had the 4th and 5th gen rears wear quicker than the front (usually need a rear replacement about 15-20K miles sooner than the front), but I've been used to at least 45-50K out of the rears and 50-65K out of the front (just guessing). 10-15K from the rears like I'm estimating now is waaaay too soon.

 

Yeah, sounds like you have something going on there.

 

Replaced rear brakes in my 2021 at about 22k miles. They needed it. Blew my mind.

 

Ensure caliper slides are free and not binding.

 

Did you put silicone grease on the caliper pins? Too much grease or too little grease can cause problems.

 

Hi all, OP returning here...

I broke down both the fronts and the rears this weekend. All calipers seemed to compress back OK when I was removing the pads. The slide pins on the rear were clean and lubricated, not too much, but I re-did them since I had them apart. Fronts were a little gummy from grease, so I cleaned them off and lubricated just the pins as well.

I did look back in my paperwork to find that I used Napa Silentguard pads. Apparently the Silentguard are ceramic for the front pads and semi-metallic for the rear. I've read that the semi-metallics can be harsh and also wear faster than ceramic. So I replaced the rears with a new set of ceramic pads since I had them apart.

Attached is a couple of pictures of before and after. I may have exaggerated the wear, I would say I was at about 50% after 10K miles. The photo angle makes it look uneven, but both sides were fairly even.

Will see how it goes...