Brakes-why did they wear out like this

[WeeYari]

Changed out my brake pads yesterday and was appalled by what I found. Ended up rushing out to Toyota for some new rotors.

Can anyone explain why both the driver and passenger side brakes wore out in an identical, and in my opinion, abnormal manner?

1) Both outside rotor surface and pads, normal expected appearance.
2) Both inside rotor surface and pads, extreme ridging.

These brakes had close to 84,000 kms on them, and by the look of things, the outer pads could have lasted another 20K.

(DIY Brake job, unheated garage, -15C, FTL )

[Klink10]

It appears to me as though you might have had alot of debris lodged between tha pads and rotors on and off up until now. Also, do they salt the roads there during winter? I'll bet that change was cold.....bbbbbbbbrrrrrrrr.

[CTScott]

Looks like the pistons are not retracting. I'd at least change the brake fluid. It might not be a bad idea to rebuild or replace the calipers as well.

[supmet]

Originally Posted by CTScott

Looks like the pistons are not retracting. I'd at least change the brake fluid. It might not be a bad idea to rebuild or replace the calipers as well.

50,000 miles without the pistons retracting? I think not.

Klink is right, that's salt, almost for sure.

[CTScott]

Originally Posted by supmet

50,000 miles without the pistons retracting? I think not.

Klink is right, that's salt, almost for sure.

Not 50K without them retracting. Once they stop retracting properly the wear happens very quickly.

Two weekends ago I changed the calipers and rotors on a friend's daughter's Nissan Altima. She just had the pads and rotors replaced about 5K ago, but they were making a horrible metal on metal sound, so they brought the car by so we could check it out in my heated garage. The outside pads looked like brand new and the insides did not have a trace of pad material left and the rotors were destroyed. We popped the pistons out of the calipers and they were severely corroded.

[Tamago]

check the brake pins.. the calipers float on these pins, and they may be bent or corroded

[Klink10]

Yea those rubber boots and seals will go bad. I bet if those pistons were that bad that seal had a crack allowing moisture to get in. It pays to not wait until pad replacement time to check the inner workings of the calipers and lube the pins.

[Christopher]

84K on a set of factory brakes. That pretty good in my book!

[YarisSedan]

Thats just normal wear. YOu will never get even wear unless you have a dual piston calper setup. One pad gently rides against the rotor while the piston pushes against the other one causing it to clamp down. Its possible the caliper needs relubing too causing it to slightly bind up. But on a single piston setup this is entirely normal.

[rningonfumes]

I realize you work on cars but that doesn't look like normal wear.

[silver_echo]

there was a TSB about the front brakes in areas with snow/ice, and salt/chemicals on the roads...

[WeeYari]

Originally Posted by Tamago

check the brake pins.. the calipers float on these pins, and they may be bent or corroded

Checked pins last night and they all slide freely. Pistons compressed easily enough at reassembly time last weekend so I'm thinking corrosion there is not an issue. Just have to keep an eye on how the replacements are wearing.

Originally Posted by silver_echo

there was a TSB about the front brakes in areas with snow/ice, and salt/chemicals on the roads...

Not listed in our compilation of TSBs. Do you have any details?

[Tamago]

did you check to see that the pins were not bent? they could slide smoothly with no braking pressure on them, and bind under load.

[1stToyota]

Originally Posted by Tamago

did you check to see that the pins were not bent? they could slide smoothly with no braking pressure on them, and bind under load.

Wouldn't pin problems most likely cause outboard wear, or crooked pad wear? And inboard pad problems are from a sticking piston, either from square-cut o-ring not rolling back or corrosion buildup inside the caliper?

I'm guessing buildup between inboard pad and rotor and nothing wrong with hardware.

[silver_echo]

Originally Posted by WeeYari

Not listed in our compilation of TSBs. Do you have any details?

it was on the echo... but i think that it connected across... i will have to check when i get to school next week

[360cubes]

Originally Posted by YarisSedan

Thats just normal wear. YOu will never get even wear unless you have a dual piston calper setup. One pad gently rides against the rotor while the piston pushes against the other one causing it to clamp down. Its possible the caliper needs relubing too causing it to slightly bind up. But on a single piston setup this is entirely normal.

I get normal wear on all my vehicles. Two of which tow 5K-9,000 lbs and are single piston design with drums on the rear. I change the brakes every 18 months and each pad has 20-25% of wear left. Nothing as significant as having one side worn 40% than the other.

Still, I'd check the pressures coming from the brake proportioning valve. I've never had pads wear that uneven, and I've done over 100 brake jobs. The lower right photo shows a clean appearance on the rotor. That's how ALL sides should look - smooth. Having a pad only touch 1.5cm of area on one side of the rotor as in the first few photos leads me to believe something is definitely amiss, as both rotors have the same wear mark.

At least you noticed this. If you would have had the brakes done at a shop or dealer, you'd probably never know about this potential problem. Even with 84K on this set, that's not bad. You are right however, if the pads wore evenly they would have lasted another 15-20,000kms easily, especially in such a light vehicle.