I just put a new power steering pump and bear box in my 1999 ram. All went well I bled the air out of the system and went for a drive but after applying the brakes it feels like the brakes are slow to release? Brakes worked fine with the old pump. The old pump (OEM) was SHOT I had a bad leak in the gear box and ran the pump low on fluid and it started wining. Steering is working fine and no leaks. I was only able to take it for a short drive found the seal leaking between the vacuum pump and power steering pump leaking. Would have changed it out if my friendly NAPA would have been able to get the seal kit!! So waiting on the new seal kit to show up from Cummins Dealer and replacing it ASAP. I guessing there's air in the system still? I hope just didn't run it long enough to bleed the system and I just have a air trap in the hydroboost. Just looking for ideas as to what could be causing this to start trying to get this fixed. Hope it not a bad hydroboot.
Thanks!!

 

Sounds more like caliper sliders, may want to grease those lightly. Assuming you are talking disc brakes...

Rear drums may need an inspection...

 

Something else to consider is the hydroboost doesn't draw the brakes off, they simply release due to a drop in application pressure, and it is usually under a millimeter. Enough to allow the wheel to free spin....you have other issues with sticky brakes.

 

Had the same problem after a PS pump rebuild... made me pull my hair..

In my case it was the brake pedal return spring that was weak. With the old pump it was "good enough" to release the brakes, still the pedal rode low but with insufficient brake boosting it would not be felt too bad. With higher pressure in the boost system the springs in the rear drum had less effect in pushing back the pedal.
A simple check is to use the brake and then to lift the pedal with your foot, if they release immediately you know where to look.

HTH

 

One thing that very often gets over looked is the rubber hoses connecting the calipers to the brake system. I have seen them rot on the inside and essentially become a one way valve of sorts.

When you are forcing fluid under pressure through the hose during braking the pressure is high enough to get by the obstructions in the hose but when you let off the peddle the fluid in the hose can not flow backwards because of the pressure drop, essentially causing the brakes to hang up.

Something to consider if the hoses are old.