coltri mch 6 tips

[paddydiver]

So, I'm going to look at a second hand mch6 electric compressor. Its 7 years old, lightly used (about 50 fills) good price. Any advice on things to look out for? Anybody have experience with a similar compressor?
Cheers for any feedback

 

[SurfLung]

It's my understanding that the 4th stage has potential for getting broken in some way due to it being on the bottom where oil and moisture can settle. If is forced to cycle rapidly when full of moisture and oil, the hydraulic forces can cause damage. This is why the manual says to have the drain valves open when you start up. So, I would say to slowly rotate the fan or the drive pulley slowly to see that nothing is froze up or broken and it rotates smoothly.

Check the oil. Dirty is not good but at least it was lubed when used last. You can cover the intake with your hand and see if it sucks air when you rotate it. A really big thing is if the owner will just turn it on and show you that it works. The used Aero MCH6 that I bought had been sitting unused since the '80s, so starting it up was not possible. About the only thing I could think of to check was the 4th stage and that it rotated smoothly.

 

[paddydiver]

Thanks for that. Yeah I'm going to bring a tank or two to fill and see it running