Anyone know what this is? If I press on the brakes normally, it stops fine. If I push hard for a sudden stop, something awful starts. Either one or all brakes locks up and skids (can't tell which it is) then unlocks and runs on a long time, then locks and skids again, then unlocks...all makes for a huge stopping distance, much more than trying a slow, controlled stop. The whole truck is jerking which this is going on. When it runs between skids it the truck seems to be freewheeling a long way even though I have the breaks on. This is a 4x4 quad cab. It feels like the ABS that is supposed to have short pulses has hard and infrequent ones.

 

replace your caliper....its likely busted....

 

Any idea how to tell if it's busted? It works ago with slow speed stopping.

 

I would have it checked out by a mechanic. Somebody on the forum may have had the same problem, but your brakes are too important to leave to chance. Even though they work fine during normal use, it may get worse. If I where in your position I'd park it until it can get checked out by a pro, just to be on the safe side.

 

If anyone has this problem, here's what it was: there is some kind of hydraulic valve that mounts near the master cylinder that was bad. Dodge amazingly doesn't stock a repair part for it anymore. The mechanic was able to fix it using an aftermarket part.

 

thanks for the post, i have a similar problem though not quite as severe as you describe.

 

sounds like it was the proportioning valve that went awry, maybe the ABS valve as well.