Hey guys, a I am having some problems and want to try and fix it them myself. I have a 1983 f-250, w/the 6.9 The truck was parked from july to sept so I could replace the steering gear seals and the fuel pump. When I started driving it again a few things happened. When I press on the brakes they don't respond well, I have to press real hard to stop the rig. At highway speeds and high idling the brakes work fine. The dash brake light is on all the time except at high speeds. The vacuum pump hoses appear fine, the belt is on the pump and the pump is turning, it is not using fluid, so wheel cylinders are not the culprit. I am thinking vacuum pump or brake master cyl, I don't want to buy parts and started hanging them until I fix it, any ideas out there? Thanks

 

Im beting on your Power Brake Booster.

Your diapram (sp?) is probely getting ready to go out and only provids assist when there is high vaccum on the engine (little load or high idle).

later,
Dustin

 

put a new vac pump on and you will be fixed.............

 

SOUNDS LIKE VACUUM PUMp

 

I'm a shop foreman for a ford dealer ship I see these all the time i can almost garuntee that is the problem... hope it works for you