[Coupeguy2001]

Another thing to think about.
The return to pump reservoir line is basically a cooling line. You understand that it is a fluid bleed-off to get the fluid through the booster and back to the pumo to keep it cool. There might be another reason for it, but I had a booster I bought overhauled, and a booster I got from another truck.
The bypass fittings on the boosters are different. One is larger than the other
I started off using the small one, and the steering was more sensitive than when I put the larger one on with a larger hose.

Don't know if the fluid got any cooler.