I have a pump to change today, my 97 has been progressively leaking more and more...
Has anyone noticed a difference after they eliminated the EVO with the kit?
Is there any real change in steering effort?
I never noticed a difference - mine had EVO then I got it removed in the process of trying to eliminate issues with the steering system (after each of 3 steering gear replacements the system was not able to be bled of air successfully). I had the shop manual and remember reading about the EVO system there. Its purpose was for safety in order to prevent or reduce the likelihood that the driver would over-correct during a high-speed maneuver, which most likely would roll the vehicle. I'm pretty sure that under anything but a very-quick turn at high speed (which would be very dangerous) you would not notice a difference. I know I never noticed a difference.
By the way, removing the EVO didn't eliminate the problem with air getting in to the system. That problem was finally resolved when I found a used steering gear in a working '96 Astro that had been turned in for recycling. I removed it with help of a salvage yard mechanic. A lot of the fluid remained in it. Back at home, with used P/S hoses I had, I tested it before putting it in the vehicle. In exactly the same way and using the same used hoses, after I pulled it out of the vehicle, I tested the almost-new aftermarket gear I had received under warrantee service. The recommended bleeding procedure involving 20 to 40 simulated turns worked as expected for the used gear (bubbles went away before 40 turns), but bubbles did not stop coming from the gear after any number of simulated turns with the aftermarket steering gear under test. The used gear fixed the problem in the van also - the bubbles in fluid and hiss finally ceased once and for all. I concluded there was probably something being done wrong at more than one facility that rebuilds the steering gears. If you're interested, the saga of my steering problem is recorded on this site (viewtopic.php?f=46&t=27202
). I don't wish a problem like it upon anyone! It took so long to fix as a DIY mechanic that in the mean time we bought another minivan when a deal came along. I just sold that 97 Astro, which I have hope still has many miles left in it for the new owner. It was at 187K.