95 F250 7.3 PSD
First time I step on the brakes they are fine. If they are pumped while coming to a stop they require a lot of foot pressure to stop. No warning lamps. Vacuum is 11" @ idle, 19" @ 2500 rpm. Vacuum stays at those values with the engine off. What should the vacuum be.

 

Weclome to FTE!
If you pump them to much the will get hard

 

The first brake pedal application is normal braking. Any braking after that requires great foot pressure to stop (no power assist). If the truck is in neutral at speed and increase engine rpm while coasting, the brakes are good. Coasting at idle the brakes are hard.

 

I just had a weird brake problem.. similar to what your describing, turned out to be the brake booster

 

Im having about the same problem it seems... My brakes are alright the first hit, but if I tap them again they go hard, but if I increase rpms, they go softer. Vacuum pump was replaced last year, a Re-man from O'Reilly's. So im not sure what it is... I just downshift and use brakes as little as possible atm,

 

When the vacuum readings were taken the gauge was inserted into the hose removed from the booster. If we know the vacuum readings from on a healthy system, maybe we could determine if the vacuum pump or the booster is the problem.

 

Spec calls for 17-21 at idle.

Go to section 06-00 -> Pinpoint Test .. scroll down to N1 - Vacuum Check on the link below.

1996 Bronco/F-Series Workshop Manual

That should lead you in the right direction.

 

The vacuum staying steady in and earlier post was through the booster check valve. Climate control has a leak, pinched closed for now. Vacuum reading from vacuum pump hose 11" @ idle. Will replace vacuum pump then look into climate control. Thank You for the help. Will update when done.

 

Replaced vacuum pump, brakes are good. Vacuum reading @ idle 23.5" , 25" with climate control hose clamped shut. Will troubleshoot climate control leak.

Thank You

 

Thank you for reporting back on the fix. We kind of like that ...