How often do brake pads wear unevenly?

[mrbreezeet1]

How often have you seen or have you ever seen disc brake pads where a the inner pad by the piston(s) was worn out, but the outer pad still look good enough that it would pass inspection?

What I'm getting at here is if you look only at the outer pad thickness that is left, how decent of an indicator is that whether or not the inner pad would probably also be good enough to pass inspection without actually looking at the inner pad?

And one other question, if the slide pins don't slide very well isn't it usually the inner pad that ends up getting worn out quicker?

Plenty of times!
Agree! Always pull the wheels and if in doubt or the inner pad is "close" pull the caliper! You don't want to get in trouble on a state inspection! {or loose your own brakes!}
Yes!

 

[John105]

Quite often which is why the calipers come off and the pads come out on every PA inspection I perform.

I live in PA. Glad you actually inspect. On our cars I see X’s for wheels pulled and am very certain they weren’t. Seems many shops focus on emissions.

 

[mrbreezeet1]

I live in PA. Glad you actually inspect. On our cars I see X’s for wheels pulled and am very certain they weren’t. Seems many shops focus on emissions.

When l inspected in PA my one boss used to bust my @$$ all the time for wanting to pull all 4 wheels, since the state said we only legally had to pull 2, {Too much time} we butted heads over that all the time.
One day l snuck all 4 wheels off {or something, long time ago} l said SEE the wheel cylinder is frozen, and one of the shoes is all wore out and the other on is good!
Another boss busted my @$$ for taking too long putting pads on a car, because l was lubing everything, meanwhile it WAS A COMEBACK because of squeal! I said for crumb sakes, do you want us to have to do it a 3rd, time! {he walked away....lol}

 

[Donald]

Here in the desert you can go 20 years and the calipers still have plenty of factory lube and the pads wear evenly.

But it's 120F in the desert. Too hot for humans.

 

[930.engineering]

I was specifically talking about the area on the caliper bracket where the SS clips fits. The area either needs to be sandblasted or filed if rust is present. If you brush it with a wire brush or nylon brush you will only polish the rust.

Two of my cars have zink plated caliper brackets (both TRW), that's a relevant sliding part of any floating caliper. If they reveal rust it's perhaps time to consider new brackets. I replaced them on all corners on the Mini this year.
.

 

[Dave9]

True, it happens. But, many (iron) calipers are partially zink coated (eg most BMW calipers), in particular on their sliding areas and they must not sandblasted, not even treated with a steel brush or even with a file. Use a nylon brush (and some thin layer of antiseize) only or they will inevitably rust even more than before. If you don't have an appropriate nylon brush on hand, just use a toothbrush.
.

Zinc plating is mostly for cosmetics coming out of the box new. Yes it's also a certain amount of protection but it is typically only after that coating wears off, which is why the rust appears, that someone has the urge to file or metal wire brush it off.

That is unless that coating was put on too thick (seen it more than once) so the pads do not fit without removing some. It's not a big deal, slap down some silicone paste if bare iron is exposed, or even if it isn't.

 

[Dave9]

Two of my cars have zink plated caliper brackets (both TRW), that's a relevant sliding part of any floating caliper. If they reveal rust it's perhaps time to consider new brackets. I replaced them on all corners on the Mini this year.
.

Replace what you want, but new brackets are a waste of money when you can just clean (derust) and grease them, unless it is a weak design plus many years of rust to the point where they are structurally compromised, which is essentially a recall-worthy situation.

If you have very open wheel spokes and consider it unsightly looking, that is a different matter, to pay for cosmetic appearances sake instead of DIY painting.

 

[Timmastertech]

I live in PA. Glad you actually inspect. On our cars I see X’s for wheels pulled and am very certain they weren’t. Seems many shops focus on emissions.

I always write the brake measurements on the back of the sticker for all 4 wheels. Makes a fast way to check when the customer asks "how were my brakes at inspection" I dont have to pull their service history up in our shop management.