Thank you all for your replies.
PAR, my system uses R134 and I have capped both tubes. I will seek professional help tomorrow. The reason I was asking about a removable air filter is that I cannot access the unit for periodic cleaning of condenser coils, hence adding an air filter that could be easily removed for cleaning or replacing. I was thinking of fabricating an air filter box of light plywood
to be placed in the intake vent to the unit that would hold a/or part of a filter element commonly used in HVAC
system. Has anybody tried this before?
Thanks again for your help.