My F150 went the first 80,000 miles with no problem, but since that time I have a problem with warped rotors, currently 190,000. It shakes as you try to stop. I had the rotors turned. Lasted about 5000 miles and then warped again. Replaced the rotors, warped again. Turned rotors, warped again. Been driving with them warped trying to figure out what is causing them to warp. Wondering if there is something that is causing most of the braking load to be on the front brakes.
Several other things about the brakes need checked as well.
One thing that may heat up rotors is a constant pressure on the pads. Be certain that the pad’s slide pins are well lubricated so the pads release pressure properly.
If you’re the same driver as the first 80k…
Have you changed addresses or driving area so as to be braking in a different manner now ?
Have you added addition drivers who brake more often, harder, or ride the brake ?
What brand and type of pads and rotrors are on it ?
“turned” rotors are more prone to warp to begin with, especially on a heavy vehicle thke the F150.
There is a device called a “proportioning valve” that controls how much brake load is on the front and how much on the rear, however that is NOT the problem. Your brakes should be loading at about 75-80% front and 20-25% rear anyway. If you see that “polished” look on the rear discs, your rear brakes are doing their part. Only if the rear discs looked unused would I consider the proportioning valve suspect.
How did you determine that the discs were warped? By lateral runout measurement with a dial gage or just by pedal pulsation? If it’s onlt by the pedal, have the discs measured for warpage. It might be that something is on a portion of the rotors causing uneven friction. If the mechanic failed to clean the discs with brake cleener (or some other solvent) prior to installation, that’ll result in residue from the rust preventatuve coating applied for shipping and that’ll cause pulsations.
@Sam13 are you certain the ABS isn’t kicking in as you hit the brakes?