1998 to 1996 Vortec 5.7 power steering pump swap

[Websterp55]

Can I remove the EVO electric plug on a 98 power steering pump and just replace it with a high pressure line in order to install it on a 96 that does not have the EVO? I have a 98 parts truck and a 96 I am fixing up. I didn't realize the power steering pumps were different.

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[Supercharged111]

They operate at different pressures. If you just swap it over like that it will work, but maybe not forever. GM did use a line section to delete EVO, but it was still paired with the EVO box. That said, I don't understand what differentiates that line functionally from simply unplugging the sensor and running full boost all the time because apparently doing that blows up the high pressure line.

 

[GoToGuy]

I have not removed the fitting to look at the pump base. But i would gently remove it and look if its just an adapter and pump bodies are the same. Makes more sense than a new design. Good luck.

 

[GoToGuy]

A GM tech, when i asked why does my truck K2500 have much firmer steering than the k2500 suburban? I can steer the sub' with one finger? He said " GM turned up the pressure because all the soccer moms complained, love the big SUV but hard to steer. I don't think it has to do with " blowing up the pressure line" . It has to do with maintaining pressure at low rpm and turning demands.

 

[1998_K1500_Sub]

You can remove the EVO from the pump but, to use the pump, you have to replace the EVO with a fitting, as shown in the attached document and referred to as "union fitting" (the document is from the GM EVO delete kit # 19168825). Once that fitting is in place, a high-pressure line from a non-EVO vehilcle can be used.

The U-shaped pipe shown in the attached (aka "EVO SOLENOID BYPASS TUBE") is only employed if one deletes the EVO and wants to use / retain the high-pressure line which is original on an EVO-equipped truck.

The document posted by GoToGuy is mostly relevant when a non-EVO pump's being used as a replacement on an EVO vehicle, i.e., the replacement pump already has the "union fitting" and the vehicle already has the high-pressure line which is original on an EVO-equipped truck. That document specifically mentions the "EVO SOLENOID BYPASS TUBE" but makes no mention of the "union fitting". It DOES state "If you are replacing only the EVO valve and not the pump, you will need to order OEM GM Kit # 19168825". That kit contains BOTH the "union fitting" and the "EVO SOLENOID BYPASS TUBE".

Confused? You should be. But I "been there" and I "done this" and that's "how it is"

 

[Supercharged111]

You can remove the EVO from the pump but you have to replace it with a fitting, as shown in the attached (from GM). Once that fitting is in place, a highi-pressure line from a non-EVO vehilcle can be used.

The U-shaped pipe shown in the attached is only employe if one deletes the EVO and wants to use high-pressure line which is original on an EVO-equipped truck.

I used a GM reman pump with that line section, but it accepted the original EVO line. I believe that's the whole point of GM's EVO delete.

 

[1998_K1500_Sub]

I used a GM reman pump with that line section, but it accepted the original EVO line. I believe that's the whole point of GM's EVO delete.

GM's EVO delete Kit # 19168825 contains BOTH the "union fitting" and the "EVO SOLENOID BYPASS TUBE", allowing one to retain the original pump after removing the EVO. I would claim "that is the whole point of GM's EVO delete".

See the document I posted prior.

 

[AuroraGirl]

EVO is definitely more understandable if you drive a roadmaster, Caprice, impala, from the tbi era vs a truck. Even then, I PREFER floaty so I would prob get rid of it too lol

 

[Supercharged111]

Ahh, that union fitting must the secret sauce that bumps the pressure down isn't it? Then of course the tube lets you keep the original line. I see said the blind man.

 

[1998_K1500_Sub]

Ahh, that union fitting must the secret sauce that bumps the pressure down isn't it? Then of course the tube lets you keep the original line. I see said the blind man.

Yes, there are fluid paths in that "union fitting" that appear to feed back in the pump. I suspect it's part of the "flow control" hydraulic circuit, and it's function is akin to setting the "electronically controlled orifice" to a fixed, one-size-fits-all setting... "suspect", as I haven't proven this.