Rotary Oil Change

[NoL]

Anyone have any tips on changing the oil in a rotary? I need/want to replace with Zerol 150 for a low temp application around -70C with no oil sep.

[RANGER1]

What type of rotary and refrigerant ?

[NoL]

Not really sure as to type, the compressor is a 1/2hp, 5600btuh Rechi Rotary. Someone told me that I simply need to turn it on once, as right now the internal mechanism is probably holding the valve closed, and pouring a big juice can with one hole in it never works.