I have a '99 F150 XLT 4x4, average use (very little off-road), 45K miles, with 17" wheels. For about the last 4 months I've noticed that it seems to "hop" when braking, but only when the speed drops to about 5-10 mph. When first applying brakes it's not felt, only when slow enough to turn a corner, for instance. Rotors looked okay but not turned--yet. I don't feel a pulsing in the brake pedal, it just feels the whole truck is SLIGHTLY hopping.
Any ideas? thanks

 

Warped rotors will give you that hop sensation, usually front, but rear can cause the same problem. Fords are known to have thin rotors and I have had several warp on me in the past. And once you turn them it is easy to warp them again. (from a lot of hard stopping, continuous late braking) If you can check the runout of the rotor with a dial indicator on a magnetic base. If it is over a few thousandths that is the "hopping" that you are feeling. I am not sure what the exact specs are, if you have a ford manual it will say, if not ask me and I will call my pops up, he has a manual for a 2001. Then I will post it here for ya.

Get them turned, put new pads on, and break the rotors in gently.

Brian

 

Before i had the rotors turned i would price new ones.I bought them for an 89 van for $25 each at Napa even,and for my 82 Mustang they were only $17 at Autozone.The last time i knew it was $8 to turn them and a couple days to get them back.

 

My truck does the same thing. I can't really tell if it's the front discs or rear drums. Front pads were changed about 20,000 miles back, but the rotors have not been turned. I haven't had any work done on the rear. At 83,000 miles now.

The thing that really bugs me is that when a dealer does the brakes, they never recommend how to properly break in the new pads or rotors. They just give you the keys and send you on your way to warp the rotors at the first stop light.

 

I've been seeing the same thing for the past couple of months. Extremely strange, cuz it wasn't all the time. This past Friday night I felt it really bad, so Saturday I pulled the wheels and pads.....took a caliper and measured the rotors. Even all the way around, but when I set them on the garage floor, sure as heck, there was just the smallest deviation when checking "side to side". I picked up a set of Aimco rotors and stuck them on........new pads......and smoothe as silk now. $100 for everything and I know it's done better than any dealership or "brake specialist". Pretty amazing how being just the slightest out of square will do that.

 

when you don't feel it in the pedal it could be bad shocks or tires that have not been rotated enough or at all.

my guess would be shocks because you stated that it happens on low speed turns while braking. which is when the suspension is all loaded up and off center.

 

I also would go with Warped rotors my old truck did the same thing and replaceing them was the cure.

 

AjRagno, how would the first stop warp the rotors???? They probably think that you are smart enough to know that you should take it easy for the first 100 miles or so. If you own a car that is pretty much general practice isn't it??? Rotors warp when they cant effectively get rid of the heat that is produced under hard braking, really hard braking or towing heavy loads. Just my two cents.