Brake Problems

[ACFarmer]

My buddy had the brakes go out on his 99 F-350. He replaced both the master cylinder and the hydroboost. Now it will stop but when he pushed the pedal down, it wont come back up and the brakes stay locked up. Any ideas? When you shut the truck off they will release and the pedal comes back up. Bad new parts maybe? I'm supposed to go look at it tonight but figured I'd ask before I drive up there and spend forever trying to figure it out for him.

 

[ACFarmer]

Anybody?

 

[Arisley]

Got some hydroboost lines hooked up backwards?

Never seen or heard of that one before.

 

[ACFarmer]

I' m not sure, he replaced the parts and then called me with this problem lol. I've never heard of anything like that either. Guess I'll go take a look.

 

[JLDickmon]

when the hydroboost unit is bad, one of the symptoms is slow pedal return.. I'm thinking defect unit..