hydroboost and steering - trouble

[crawlink5]

Did a search but didn't see anything that matched what is going on. I need to drive this thing to work tomorrow. I am in a bind. AND, the wife is not happy as it's been under the carport for 2 months.

It turns perfect until I hit the brake pedal then it loses power steering. If I even tap the brake the steering goes out until I let up.

I just put a Cummins in my truck and it already had the PS pump on it. I have never dealt with hydroboost before.

1978 Chevy Bonanza Blazer (great shape I might add - New Mexico truck)
Rebuilt Cummins 4BT
Chevy NV4500 mated to an NP465 Bellhousing w/o adapter
NP205 32 spline mated to the NV4500 w/o adapter
14 Bolt FF Rear with Eldorado disc brakes
Dana 60 front with d60 calipers

Everything above but the rear was just put in. Cranked it for the first time Friday. I have about 20 minutes run time on the motor. Before this the PS pump sat up on the engine full of oil for about 2 years.

I installed new lines, new hydroboost, and new master cylinder. Old steering box but was having no problems with it.

I just bled the brakes again and got no air out.

Thanks - please help. I have about three more hours to work on it tonight.

 

[sandawgk5]

I say notch the fitting on the back of the PS pump where the pump outlet connects that will increase flow from idle up. Keep in mind I am working through a HB brake problem myself. Others on here are running modded pumps with HB with no problems. It sounds like a flow issue to me. Are you sure that the lines are connected properly?

Ira