Uneven brake wear - Help please

[stonnie]

Recently I noticed that the passenger side rear rotor was excessively worn. When I took the brakes off, the rear pads were completely worn, but the fronts were in good shape. I figured it was a caliper problem so I changed the rear calipers then put new rotors and brake pads on on four corners for a nice fresh start.

When I pulled in the garage yesterday, I smelled the brakes burning and sure enough when I looked, I found that the pads were worn and the rotor wearing. Basically the pads are almost completely shot. The front brake pads and rotors are just fine.

Here's where I am lost; when I put the truck on jack stands, I can turn the wheels by hand, the emergency brake works properly and the brakes work properly.

I have a fair amount of experience changing brakes but I can't figure out what's going on. The guys at Ih8mud.com told me to come over here because you guys are the experts.

Thanks in advance.

 

[fourwd1]

What kind of time period are you talking about between when you changed everything and the brake check yesterday?

 

[ekin]

Can take some time to break-in to work correctly

 

[Harmkade]

Rear brakes wear faster than I can change the oil

My rear brakes are doing something similar. I had a pad fall off a couple years ago and killed my passenger side caliper piston, and leaked all my brake fluid out. I replaced the one caliper and did rotors and pads on either side. But now my rear pads keep wearing faster and faster, I had my timing belt changed before thanksgiving 2020, and my brake pads were super low so I had them changed and now about 5,000 miles later, the pads are already down to nothing and scraping against the rotors. I’m trying to figure out if it’s a problem with a proportioning valve or if it is something else but I have no idea what else it could be.

 

[Seymore Butts]

I would look at three things:

1. Flex brake lines, when old and crusty, will act like a check valve and keep the hydraulic pressure from dropping when you release the brake pedal. Flex lines tend to degrade from the inside out.

2. Brake fitment kit. I recently had a single severely worn aftermarket brake pad on the rear due to the pad seizing in the supplied mounting clip (one of Federal Mogul brands).

3. Excessive grease on the caliper slide pins. More than just a thin coating of grease can lead to hydraulic pressure events, pushing the pads into the rotor, sometimes locking up the brake completely.

 

[rsclancy]

I would look at three things:

1. Flex brake lines, when old and crusty, will act like a check valve and keep the hydraulic pressure from dropping when you release the brake pedal. Flex lines tend to degrade from the inside out.

2. Brake fitment kit. I recently had a single severely worn aftermarket brake pad on the rear due to the pad seizing in the supplied mounting clip (one of Federal Mogul brands).

3. Excessive grease on the caliper slide pins. More than just a thin coating of grease can lead to hydraulic pressure events, pushing the pads into the rotor, sometimes locking up the brake completely.

This. Also check where the clips fit into the caliper. The brake pads should slide freely in the *new* stainless mounting hardware. If there is any crud or rust on the caliper behind the mounting clips, that can cause the pads to bind and remain pressed against the rotor. Sometimes a flat, not fat, bastard file will clean them up. Otherwise you may need something with more oomph ( die grinder, dremel, sand blaster, thermonuclear fusion... )

 

[revox92]

I would look at three things:

1. Flex brake lines, when old and crusty, will act like a check valve and keep the hydraulic pressure from dropping when you release the brake pedal. Flex lines tend to degrade from the inside out.

2. Brake fitment kit. I recently had a single severely worn aftermarket brake pad on the rear due to the pad seizing in the supplied mounting clip (one of Federal Mogul brands).

3. Excessive grease on the caliper slide pins. More than just a thin coating of grease can lead to hydraulic pressure events, pushing the pads into the rotor, sometimes locking up the brake completely.

My buddy go this new 4Runner project and it seems doing the same rear break issue. He ordered a set of tires from 4Wheelonline and we will take a closer look at the caliper and rotor while we're there.