Power Steering Rack questions

Pete_89T2 · 06-23-2012, 07:18 AM

Sounds like you have the vehicle speed sensitive rack (3 fittings), and need to use it with an engine speed sensitive PS pump. Ted's description is correct; the VSS type PS pump has an electronically controlled valve on it that takes that 2nd pressure line from the rack and bleeds off a % of the line pressure back to the PS fluid tank depending on vehicle speed.

What you'll want to do is figure out which of the 2 pressure fittings on the PS rack is for the pressure bleed/return, and just cap that fitting. There's a diagram in the FSM that illustrates the flow diagram to figure this out, but I don't have it in front of me now.

Only potential downside I see to this is you might be getting more PS assist out of this setup than you want. The VSS type rack is probably calibrated to give enough PS assist at idle/parking lot speeds. Without that VSS feedback loop controling the assist as the line pressure rises with RPMs, as your engine RPMs go up, so will your PS assist.

06-23-2012, 07:18 AM	#1
Pete_89T2 Lifetime Rotorhead Join Date: Apr 2010 Location: Elkton, MD Posts: 874 Rep Power: 16	Sounds like you have the vehicle speed sensitive rack (3 fittings), and need to use it with an engine speed sensitive PS pump. Ted's description is correct; the VSS type PS pump has an electronically controlled valve on it that takes that 2nd pressure line from the rack and bleeds off a % of the line pressure back to the PS fluid tank depending on vehicle speed. What you'll want to do is figure out which of the 2 pressure fittings on the PS rack is for the pressure bleed/return, and just cap that fitting. There's a diagram in the FSM that illustrates the flow diagram to figure this out, but I don't have it in front of me now. Only potential downside I see to this is you might be getting more PS assist out of this setup than you want. The VSS type rack is probably calibrated to give enough PS assist at idle/parking lot speeds. Without that VSS feedback loop controling the assist as the line pressure rises with RPMs, as your engine RPMs go up, so will your PS assist.