Thanks Sky
I am doing some hopefully(!) unnecessary research on completely replacing the AP if I have to. If I do so it would be with a Garmin system and the pump size (and system price) is pretty much dependent on the volume of the steering ram.
The day I left the boat, the autopilot quit working. It's an original Raytheon Neco that came installed on the boat from the dealer in 1980. It didn't work when we bought the boat but I went through it shortly afterward and it has worked great up to now and I DON"T want to replace it if I can sort out the problem. The solenoids that activate the valves are working but the pump won't energize. I didn't have time to check much of anything so it could be something very simple though it's not fuses or circuit breakers - I did check those.
So my question re the ram is a "just in case" for planning purposes prior to getting back to the boat.