G'day moggy, how's life in Eatsern Canada these days?

Yes; the Yanmar engines are a good motor. Moggy's right regarding having it served by someone who knows what they're doing. I deal with a lot a of guys over there, some of whom are with dealers and some who are independent. Let me know your email address on the message service and I'll see who's in your area.
With regard to maintenance, there's the basic maintenance of oil and filters which can be done by a good diesel mechanic, but then there's the annual maintenance on the refrigeration system which should be done by a good refrigeration technician (preferably someone who specializes in transport equipment).

I've been in the transport refrigeration industry for nearly 30years and always happy to help where I can.

Please let me know if you any specific information about the unit.

Best regards; Tony