low steering pressure - It was due to an EVO
 

I recently swapped an 02 ls into my 71 and used the 02 power steering pump with my factory 71 gear box and hoses.
My issue is I feel like steering should be easier than what I'm experiencing. I went many months before the swap without power steering but now with a new motor and pump it's only slightly easier to steer but still requires effort.

What do you guys suggest?

Re: low steering pressure
 

Watching this post, I am having similar issues, sometimes goes to almost nothing. Not sure if it is pump

Re: low steering pressure
 

I used my o2 ls pump..steers with one finger...most likely the pump needs replacing..if your using original hoses they also could be deteriorating from age

Re: low steering pressure
 

Could it be possible a valve is stuck? I've never been into a power steering pump so I'm not familiar with the internals.

Re: low steering pressure
 

The modern pumps on LS motors should be over-driving the old gear systems. Most common result is one-finger cadillac steering.

If your feeling is heavy, then you could;
Have a physical obstruction/drag on the sytem.
Be foaming your PS fluid and not building hydraulic pressure (note this if your running a cooler or anything)
Have a pressure leak in the system
Bad or dying pump (there are a couple of styles of pump fwiw)

Re: low steering pressure
 

check fluid level

debris could also be in there somewhere.

i just rebuilt my PS pump for 4.8 using Edelman kit from rock auto and put in a fluid filter

Tx firefighter put a steering box rebuild thread up and i followed it to rebuild my box.

no issue at all

Re: low steering pressure
 

Alright here is where I am at.
Today I pulled my power steering pump and found that the high pressure port I have been using is different than what I should be using. Here is the strange fitting on the back side of my pump:

Attachment 1663602
The portion that is partially covering the red bucket in the background is where my pressure line was fitted to.

From what I have seen, my pressure line should instead be fitted directly to back of the pump as is the normal convention on older pumps. The issue is I no longer have the 1 inch fitting that adapts the pump threads to the pressure hose male threads.

The last two images are after I took apart the adapter piece and found the flow ports to be rather small. From the first picture you can see this thing has a sensor on it. My guess is it is some sort of temperature sensor for the metered flow rate but what do I know.
Attachment 1663603
Attachment 1663604

Re: low steering pressure
 

Interesting. My 04, 05, and 08 all didn't have that, but they were hydroboost equipped trucks.

Re: low steering pressure
 

I seriously doubt that is an '02 pump, looks way newer to me. I would try and find the fitting out of an older non LS pump and thread that back in. That is provided your hose is a flare type and not an o ring type.

Re: low steering pressure
 

That's an EVO fitting which I think stands for "Electronically Variable Orifice". It was an option in '02 and even the previous generation of C/K trucks. I think it was called Magnasteer back then. At any rate, I've just seen some information about them in passing and I'm not sure how the system works. You could probably Google up all you want to know about them now that you know what they're called. I'd take ls1nova71's advice and replace the EVO fitting with a standard high pressure pump fitting.

Re: low steering pressure
 

It could be out of an 02, more likely if it was an Avalanche. Its an EVO/TFE actuator...which I just found out after reading like 8 pages on the fact that GM discontinued them.

From what I read, this gets used instead.
https://www.amazon.com/Genuine-19168.../dp/B00GV8840I

edit: dayj got me on the wholeshot on the answer.

Re: low steering pressure
 

Thanks everyone for the detective work. From what I can tell you can't just bypass the solenoid either as it is PWM.
So as suggested I ordered the GM 19168825 from amazon to replace this stupid thing. It should be here Friday and then I can be done with this nonsense.

I will submit a final post (if I can remember to) on this once I get in the adapter for future reference should anyone be in the same boat.

Re: low steering pressure
 

Well I guess this can be chalked up to the "you learn something new every day" category. I've been swapping LS engines for 17 years and have never seen a fitting like that, or even ever heard of Magnasteer! Now im curious, what did this engine come out of? Must have been some loaded truck with a lot of fancy bells and whistles, like an Esclade or something? Is it DBW too? Because surely it had traction control if it had some crazy optional steering!

Re: low steering pressure
 

thats new to me also. changing the fitting me be your fix

Re: low steering pressure
 

From what I can find, its in crossover year Escalades, Avalanches, and possibly a few Regency and high option trucks(99-02). The compatibility list also goes into some older NBS stuff too.

Re: low steering pressure
 

Alright here is the end to this fiasco.
I got in my adapter piece from Amazon:
Attachment 1664383

Then I attached everything back up as such:
Attachment 1664384

But then I immediately had an issue. The problem was this adapter makes use of o-rings to seal whereas the original type makes use of compression.
Attaching my factory hose to the adapter piece never fully sealed the hose therefore it leaked quite well.
So then I went looking for solutions.
From another thread I found that the adapter fitting #1446 from Napa is made to fix this issue. So I went to napa and the guy didn't even bother trying help me so then went to carquest.
There the guy took a new hose for a 72, cut off the pump side compression fitting as well as the new o-ring type from the adapter piece I got in from Amazon and soldered the new fitting to the original type hose.
Attachment 1664385

A little bit of bending later and I was able to get it all back together.
Most importantly, my power steering works again!

I would like to say a big thanks to everyone who helped me out on this one!:metal: I had never seen the stupid EVO thing before, but I understand why they aren't used anymore.
Supposively this motor was from an 02 4wd k2500 suburban. I do not know if those things have these valves on them from factory but that's what the ecu said.

Re: low steering pressure
 

My first swap came with a pump fitting like that. 2002 suburban Denali DBW wire . I just took it out and used my original power steering fitting. It's the only pump I have seen with that odd fitting