2000 Chevrolet S10 pickup truck with 2.2l engine
Automatic transmission and 175k miles.
Installing a new compressor but before gassing up the system we have to vacuum the moisture out. Once I've got the system sealed and it's under vacuum is it okay at that moment to turn the compressor pulley by hand to rotate the internal component exposure to the vacuum and ensure that all moisture is sucked out? Will that damage the internals of the compressor due to excessive vacuum on the suction port?
I've never heard of doing that and have never done it. I don't really see what it would accomplish.
It's a piston compressor. And as the pulley turns a valve turns with it and seals off some of the pistons from the tubing while exposing others according to the cycle. I have to oil it and that involves turning the pulley while it's out of the car but when I do that I'm going to draw in oil that will have moisture contamination and I want to get it out even that which is cyclically blocked off by the valve as it turns with the pulley. That's what I'm worried about but I don't want to damage it by turning it under suction
First I've heard of that being an issue and have never seen anything saying to do that when pulling vacuum. The guy I learned from (a master auto AC technician with decades of experience) never mentioned it either. Did the instructions that came with the new compressor call for that procedure?