99 F150 Brake rotor problems

brakes
f150

#1

I have had the rotors turned three times and replaced twice on this truck with 100,000 miles on it. Brakes seem fine other than a pulsing in the pedal that gets worse as the rotors fail. Good pedal and no unusual pad wear or pulling. Truck is driven only by me, and I drive it like a little old lady. Just an occasional partial load of stuff in the truck, nothing excessive. It is table top flat here, so no hills and mostly suburban/rural. No rust.



I’ve given up on having the rotors turned or replaced, as it only lasts a month or so before it starts to fail again. Anyone with any ideas?


#2

First off, which ones are the problem children? Pulsing in the pedal usually points to the rears.
Is this chronic rotor machining and replacement being done on only the front or both ends?

I have some more advice but would rather get a bit more info first. It helps to narrow it down a bit.


#3

The other part is the caliper. Just because it is the other part, you might try to move them in and out with the pads removed. If they can’t be moved without binding, there might be a problem there. Think of it as research. I don’t know if it will help. I am thinking that it isn’t the rear brakes, but it could be.


#4

a couple of other thoughts:

who did the brakes on these other jobs?

which have failed so frequently, all or just front?

how have the caliper slides and pins been lubricated, (if at all) and have you tried different pads, to make sure the brand your’e using arent the problem?

and as another said, how were the caliper pistons upon retract?? thats a big one.


#5

The front rotors are the problem children. It has drum brakes on the rear and still has the original shoes, with little wear. This is not an ABS issue, as I’ve had the ABS initiate rarely and know what that is like. Claiper pins have not been lubercated, but seem to move smoothly. I’ve tried using the most expensive “premium” metalic pads, with no change and pad wear seems even. Is there a service bulletin on this?


#6

A pulsing brake pedal usually points to the rear brakes. Take the truck out on a smooth, deserted stretch of road and from moderate speeds of around 40 MPH bring it to a stop slowly using the PARK brake.

If you feel the pulse the problem is in the rear.

Regarding the front rotors here is what can happen.
There is a possibility that you may have a loose wheel bearing, ball joint, or tie rod end.
With new or freshly machined rotors the brakes will seem to be fine.
After a little use the rotors may warp a slight amount; say a few thousandths of an inch. Normally you may not notice this but if there is looseness in a suspension part that little bit may be magnified and the brakes will feel worse than they actually are.
This is usually noticeable in the steering wheel.

Hopefully whoever is doing the rotor machining is not going too thin with them. A thinner rotor will also warp easier along with being a safety factory if they’re cut too thin.

I would say give it the PARK brake road test and see what happens.


#7

Do you have ABS? A malfunctioning wheel speed sensor on an ABS system can cause pulsing.