By golly I'd like to welcome Rick39 here. With him being from SE PA, that's the home of JLG in McConnellsburg. I've been through that plant, pretty fascinating. And yes he's spot on, the 40F machines with Bertea valves didn't like heavy viscosity oil at all, they need the viscosity of cooking oil, especially in the cold climates.
Thanks for the warm welcome, Willie and OFF.
We never tried to get bertea units to operate at -20 but as OFF says they needed 50/50 oil/kerosene. Rather thin oil indeed!
I read through most of this thread and took quite a trip down memory lane.
Started dealing with JLG's when the F's first came out in late 1976.
Hard to believe it was 40 years ago.
How times have changed... Back in the day boom lifts were still rather rare and we would travel long distances to deliver and repair them.
Customers were in awe of them back then. Now they have no more luster than a shovel in the eyes of users.
I remember driving the 40H prototype at the factory (back then if you said "the factory" everyone knew you were talking about McConnellsburg).
What a big difference in performance!