GOTMEAT

I have been having some significant brake squeal. Had to rotate the tires today so I looked at everything expecting the rears to be worn. I changed the front pads at 50k without turning the rotors. I am at 90k now. The front pads need to be changed soon, but the back outboard pads are fat while the inboard pads are thinner. I also noticed that the front rotors have circular ridges like a shallow, multi-toothed fork had been turning on them. What are the causes of "forked rotors" and little pad wear in the back vs. the front?

1-2-3

Forked looking wear pattern??? Got a pic? Different amount of pad wear is from the caliper not floating free.

GOTMEAT

Imagine what a fork would do to the surface of metal if it could groove it. Not as deep nor as uniform, but they have ridges as opposed to being flat.

Fordzilla

Sounds like a grooved rotor......Ben

Hodge

That sounds normal. Abrasives like road grit get embedded in the pads, as well as junk in the pads themselves, and it eats grooves in the rotors.
The front brakes take much more abuse than the back ones. That's why the front rotors are bigger.

JP-4.5

My back calipers froze up.. One was dragging and caused quick wear and another was like you are stating and would not wear properly. I replaced calipers and brakes have worked wonderful since changing the calipers.. My front calipers are still factory and work great.. 160k so far

PoorMansCat

Your brake proportioning valve is set to run 60-70 percent front brake and the remainder going to the rear... Hence more front brake wear..
It appears as though the factory pads on the 3rd gens create lots of front brake dust, so I would assume that translates to more wear.

EME 411

The antilock brake system (ABS) is an electronically operated, three channel brake control system. The vehicle has
Electronic Variable Brake Proportioning (EVBP) designed into the system which eliminates the combination/proportioning
valve. Quote from the 2006 repair manual.

Grit Dog

Your rear calipers aren't floating, causing the inner pad to wear faster. Take the rears apart too, replace the pads and put some anti-seize on the new slides (and the bolts too, so they're not rusted in the next time).
Probably why your fronts are waering faster as well, the rears aren't doing their job if they're only "pushing" on the rotor and not clamping it.

PoorMansCat

I wondered if they still used a mechanical proportioning valve... so its part of the ABS system now.. Makes sense.
So, its controlling brake pressure to LF, RF and rear (3 channels)???

EME 411

That is correct. The front wheel brakes are controlled individually and the rear wheel brakes in tandem.