I did the brakes on the truck ('99 F-150 117k miles) a few thousand miles ago and now under hard braking, the truck pulls hard to the right. If I'm going 50 or so and hit the brakes, the pull is hard enough to take me into the ditch. However, if I lightly apply the brakes then hit them hard, the truck doesn't pull nearly as much. I pulled the calipers off and regreased the slides and the problem is still there.

 

the caliper piston is worn to the original pads..

sorta crooked in the bore

when you installed the new pads they tried to "straighten out" the piston..

they dont like that

thus the hanging up and pulling to one side

all the grease in the world will do no good

change out the calipers... you'll see

...zap!

 

Ummm......so far I've deciphered new calipers......

 

Sounds like you have a caliper sticking or brake hose expanding.
When you did your brake job... did you replace pads and rotors??

 

Yep, replaced the rotors and pads along with new fluid.

 

I had a similar issue a while back, it was actually overheating and warping my rotor to a certain extent (driver side) - upgraded the calipers to a three-piston configuration (I'll look for the receipt to tell you where I got them if you're interested) and changed out the rotors to a set of drilled ones... problem solved.

...not that you would need to go to that extreme, but I really noticed the difference when I was braking during towing or had to come to a quick stop from high speeds...

...lol, not that there is a such thing as stopping quickly at high speeds with that truck, but it certainly felt a lot more confident under heavy braking.

 

jkingman-If you have the receipt handy that would be great. I'll be replacing the calipers later this week or during the weekend and I'll report back if anything changes.