Hydro boost question

[VetteFan427]

Does anyone know that the sensor on the back of the power steering pump is for?
I am going to replace my pump , but all the new power steering pumps come with a different line for the back of the pump. There is nothing for the wire harness to plug into.

 

[Pinger]

I think that's the valve for the EVO system. Others will be along soon to advise on your options.

 

[kennythewelder]

Yes, thats the EVO system. It gives more power assist at low speeds, and less at higher speeds. So for example, in a parking lot, your power steering is more sensitive than at 70 MPH driving down the HWY. It is not the best design. I eliminated mine when I replaced my PS pump the last time. The replacement pump had the bypass pipe all ready installed. EVO came out in 1996 I think. So 96 up trucks have it. The bypass allows you to screw your existing PS hose into the pipe on the pump, where the EVO solenoid would be. As for the wires, you can just tie them up out of the way. Or you can get a pump with the EVO system still intact.

 

[VetteFan427]

Ok cool

 

[kennythewelder]

Ok cool

Welcome to the forum, by the way.

 

[Pinger]

There are mixed views on EVO on this forum. Some really like it, others don't. What is pretty certain though is that there is a difference in how the two systems (with or without) feel when driving.
I really like my EVO (admittedly I've never driven without it) and I don't think I'd like super-light steering at all speeds. If you are similarly inclined, consider getting a pump that preserves the EVO. If not, going the other way is entirely acceptable.

I think, you can trial how it would feel without EVO by just disconnecting the electrical connector from the valve. Try before you buy?

 

[L31MaxExpress]

I personally cannot stand the EVO even when it works right. The EVO solenoid on every truck I have owned got unplugged the moment I bought it.

 

[df2x4]

I think, you can trial how it would feel without EVO by just disconnecting the electrical connector from the valve. Try before you buy?

This is a good diagnostic tool, but it puts the system in full boost at all times which creates very light steering. To the point that the steering doesn't even want to return to center at slower speeds. FWIU removing the EVO properly feels much better than just unplugging it. I'm having a bypass kit installed in the red truck on Monday so I'll be able to compare it directly to my Suburban, which still has functioning EVO.

I personally cannot stand the EVO even when it works right. The EVO solenoid on every truck I have owned got unplugged the moment I bought it.

I will never understand how this feels OK to some people. It must be something to do with the fact that you have a van. Both of my trucks feel awful with the EVO in full boost.

The EVO is great when it works, unfortunately it eventually stops doing so reliably.

 

[df2x4]

Excuse the double post but for those who may be curious, the correct way to remove EVO steering is with a GM bypass kit (part number 19168825):

www.amazon.com/ACDelco-19168825-Power-Steering-Adapter/dp/B07RY5XW7W

This removes the solenoid/valve from the pump, replaces it with a fixed size valve, and adapts the existing line to fit.

The other way to do this would be using a power steering pump and high pressure line from a '96 (the year before EVO was introduced).

 

[99bluetahoe]

The steering gear boxes are also different between the 96 non-evo gears and the 98-99 evo equiped gears. I believe some 97 might gave had evo too but no 96s. If you bypass the evo, you will have very assisted steering. This is how I have been running mine until i get a new box from companies like redhead that can set whatever assist you like.