Thank you gentlemen for the responses. Guess I've got a leak in the system somewhere.
Rick - I'm loading the wagon with gear for a fishing trip. And yes it does kick in the self leveling system.
Michael - Thanks for the info on the Shell product, I'll look around for that. I checked my Haynes manual and could not find any specific type or brand. In fact, at the front of chapter one where they list "Recommended lubricants, fluids and capacities", the Hydraulic Oil has an asterisk that says *Consult dealer for specific approved types and brands.

Also, my Haynes manual is a bit vague on the recommended level. I notice the tank has a dipstick, but it also has a maximum mark on the outside. Is the maximum mark for filling after flushing the system and the dipstick just for maintaining the proper level?

__________________
Dave
1995 C280
1999 Triumph Daytona 955I - my speed fix.
1982 300TD - Gone, but not forgotten.