I don't know of a technical procedure, possibly one of the Mercruiser manuals list something. I'll take a look tonight. To simplify, the actuator has essentially a valve that opens as the steering cable moves against the out drive arm. The more flex, the more pressure applied to the slave cylinder. Without the engine running, turn the wheel lock to lock. It should move smoothly with not much effort. When running you should be able to notice a difference. Honestly not certain how much effort the power steering applies. I have noticed on my CVZ, that once I got the prop and trim tab in harmony, you can drive with one finger. I assume PS makes up for when I'm not at the sweet spot? Other than that I'd maybe check pressures? Saginaw pumps are fairly bulletproof. On a side note, good to hear Phoenix is making a return. Any CVZ progress, little hands are great for sanding tight areas of boat hulls.
