Upgrading engine brackets & power steering pump

[jggiedeman]

I had a sweetheart deal on 97 and up engine accessory brackets and components. My question is regarding the power steering pump. It appears to have an electrical accessory on the back of the pump. Is this an electrically controlled flow/pressure component? Did they make pumps for a 1 ton 4wd that did not have this component? Safe to run without it hooked up?

Thanks for any assistance.

[Robyn]

The electrical device in the power steering pump is called the "EVO" or electronic variable orfice.

This device controls the pressure output of the pump.

IIRC, above 40 mph road speeds the pumps output pressure is dropped to help with steering stability.

In effect, this slows the reaction of the steering and helps with the stability of the vehicle.

Basically, this will stop, or help keep some idiot from loosing control if they get too wild with the wheel at higher road speeds.

This entire system is controlled through the ECM and likely has a module to activate the EVO in the pump.

Using this pump without the EVO connected should be no problem, IIRC the valve is normally open (full pressure) when the control power is off.


Sounds like you got a sweet deal.

Good luck.

Missy

[jggiedeman]

Thanks for the info Missy.

[CareyWeber]

I had a sweetheart deal on 97 and up engine accessory brackets and components. My question is regarding the power steering pump. It appears to have an electrical accessory on the back of the pump. Is this an electrically controlled flow/pressure component? Did they make pumps for a 1 ton 4wd that did not have this component? Safe to run without it hooked up?

Thanks for any assistance.

My 97 K3500 hase the electronic variable orfice (EVO).