Sight Glass has a coating brown in color.
Got a call to a catering company, walk in cooler was running at 55 F. System was low on charge (no LP switch), low side was aprox 0 psi, sight glass inside has a brown stain, very hard to see thru. System is R22, Semi H Comp. I found a small leak at High side schrader evacuated to 500 mic and charged, normal pressure, superheat good, cooler holding normal temp 38F. The oil was at bottom of compressor glass I added to just below ctr with MO. Is this brown tint any indication of system failure almost looks like dirty oil caused it or a winding burn out? If so is there any hope should I change or add filters and new oil to prevent more damage.
Thanks for any help
My guess would be someone may have dumped a bunch of dye into the system. It probably also has a bunch of moisture in it from running in a vacuum for an extended amount of time. Are you sure there aren't any more leaks on the low side? Change out the liquid line filter drier with a slightly oversized one at a minimum, and things might be ok, no guarantees though. Document everything thoroughly on your paperwork and have a manager sign it.
This is from Sporlan Bulletin 70-10:
EXCESS OIL — When a system is circulating an excessive
amount of oil, the See•All indicator paper may become saturated.
This causes the indicator to appear brown or
translucent and lose its ability to change color, but does not
permanently damage the See•All. Let the See•All remain in
the system. The circulating refrigerant will remove the
excess oil, and the indicator element will return to its proper
I looked at the article; I will check it in a week or so to see if cleared up.
Thank you for the education.
Being a semi-hermetic, I'd take a sample of the oil and if dirty or burnt smelling I'd change it. Zerol 200 TD would be a good oil to use.
However, I'd make sure the customer knows that there's no guarantee that the compressor hasn't already suffered damage and it could take a dump any time.