Front Brake rotors rusted on inside only

[dffans]

I have a 2007 Expedition XLT with 98k miles. I recently inspected by front brakes and found both rotors are rusted under the brake pads on the inside only of both rotors. The outside of the rotors under the pads are clean/smooth as normal.

I have always kept the guide pins lubricated.

Is this a caliper problem and/or master cylinder problem or something else?

As a side note, my rear brake pads have always worn faster than the fronts. I have replaced the rear pads twice, and the fronts only once and currently they still have a lot of meat on them.

Thanks

 

[stamp11127]

If you can, post a pic of what you are talking about.

 

[dffans]

will do tonight after work

 

[dffans]

See attached photos
The inside pad needs to be replaced but not down to metal on metal
I almost seems like the calipers which are on the inside are not pushing the pad against the rotor?

 

[FordandPolaris]

It looks like a salt-area rotor. I don't think the caliper could push on the outside without pushing the inside as well. I have had rear rotors get like that on all of the Expeditions in my family. Did you run it metal on metal before you changed the brakes last? Otherwise the previous owner may have done that as well and left the rotors the way they were.

 

[stamp11127]

Looks like the inside pads are wearing the most and are wedge shaped. If that is true then the caliper is not sliding on the pins. That will cause the pistons to push the inside pad against the rotor instead of clamping both pads.

From the pic the inside rotor face looks pitted. That will eat the crap out of the pads.

Flush the brake system and test the piston operation in the calipers. Place something a little thinner than the rotor thickness between the pads so that the pistons will come out farther than normal but not blow out of the bore. Push both back in all the way and repeat the process. You want a smooth travel in and out. Fluid should be clear when finished. With the pistons all the way in, place caliper with new pads on a new rotor. Have someone press the brake pedal and watch the caliper, should slide on the pins as the brakes apply, firmly pressing both pads on the rotor.

 

[dffans]

Ok, thank you for the help

 

[stamp11127]

Are you using caliper grease on the pins? The two I've used in the past were a dark blue & a dark olive green. One brand was Permatex, don't remember the other brand.

 

[mrford60]

the bias is not correct if you are wearing out rear brakes faster than front brakes. you need to do a complete brake bleed (Front and Rear) after servicing the brakes to correct your problem.

 

[BIG GREEN FORD]

That looks like your pad on the inside eat your brake disk and NOW every time you put a new one its going to eat it a lot faster

 

[BIG GREEN FORD]

And it is braking you can tell it is because where its not eaten up at its shiny

 

[dffans]

Work complete

I replaced the front rotors and brake pads yesterday. I bled the brakes and tested the calipers, which seemed to operate smoothly. I removed the guide pin boots and discovered rust build up under the rubber boot. This seemed to have caused the pins to bind and not slide easily, even when lubed up. I sanded down the rust and replaced the guide pin boots. The brakes are working much better. I think i will check the rear guide pin boots next weekend.

Don't you just love northern weather and winter salt use. everything rusts

thanks for everyone's help