I have a '05 f150 FX4 with 70k miles. Awhile back had the rear brake pads replaced by a tech. Less than 10k miles later had a horrible shuddering when applying the brakes. Took the L/R wheel off & & found the outer pad at 1/2 & inner pads metal to metal. R/R brakes looked in nice shape, like you would expect to see with the mileage they were used. When I talked to the tech that put the brakes on he was elusive & said maybe the caliper hung up in the carrier, or because I didn't replace the rotors (which looked in nice shape IMHO). I personally replaced the rear pads & rotors and made sure to replace the metal sliders where the caliper sits on the carrier. I notice now (after approx another 5-6k of miles the brakes are making a thumping noise on long braking (1 major hill from our mountain property 18% grade for a couple miles) & a slight pulsation thru the pedal. Have not pulled the wheels yet due to medical issue (hernia) which will be repaired soon. Sorry for the long story, but any suggestions?

 

I assume that I'm the only one that had this problem?

 

Yeah, I hate it when no one responds to my posts too. Especially when I post DIY guides or detailed info about my projects/upgrades...

Anyhow, it seems that you're mechanically inclined and are able to tackle the brake job yourself. Even if the rotors look new, you should at least machine them when you're replacing the pads. Unless you look at the rotors with a microscope you won't be able to see all the surface imperfections that will affect the new brake pads. You can get decent rotors for a low price these days. It's good that you replaced the sliding hardware. Did you use high temperature caliper grease on the contact surfaces? That will definitely help. Seeing that one side of your rear brakes had excessive wear and the other side did not, I'd suspect a problem with the caliper itself. If you are hearing/feeling a thump after long braking distances I would still suspect a caliper beginning to seize with higher temperatures.

 

The thumping noise is brake fade, obviously from heat going down your 18% grade.
Overheating your rotors causes hard spots to develop on the braking surface, and that produces the noise when the pads scrape over.
Try cross drilled/slotted rotors and downshift when going down hills. I've even gone down to 2nd gear at 45mph to keep off the brakes.

 

I am having the same issue that you are expirencing, except mine is on the opposite side. I havent replaced the slides yet, but i have replaced everything else. You are not the only one with this issue, I think I will try replacing the slides and maybe the caliper on mine and see if that helps.