hrdroboost power steering troubles

[towjoe]

I've replaced the power steering pump, steering box, couple of the lines ect and still have to rev up the engine to get power steering to work at a idle. hydroboost also wont work untill it's reved up. I have exchanged pump 3 times now and even tried a used one off a wrecked truck in back lot. any more ideas as to where to look? I have even replaced the main high pressure line, and changed the steering box. Had one while back that lost all power steering and come to find out the pully was spinning on the pump shaft when put under load, but this one is tight

 

[skysurfer]

If you have an extra pump you can try modifying it. http://www.gmtruckcentral.com/articles/2013/powersteeringmods/

I noticed in the article that 3500 series hb pumps have a different flow piston than light duty trucks. Is it possible the parts store was selling you the one-size-fits-all pump and not the one for your rig?

OR

PSC sells a high flow pump (but it's expensive). Looks like they also have an overdrive pulley for serpentine setups.

 

[circuitguy]

You need a high flow PS pump, make sure this is what you have installed. Also check for air or foam in the system.