TM 9-2320-364-20-22-983(1) Drain air system pressure to zero(TM 9-2320-364-10).(2) Place measuring cup under coalescingfilter drain.(3) Open drain and allow oil and othercontaminants to drain.(4) Close drain.(5) Allow oil and contaminants to settlefor at least 24 hours.(6) Determine the amount of oil in ounces(ml) that has settled on top of container.(7) Compare oil amount with engineoperating hours since last coalescingfilter draining to Table 2-33.(a) If oil amount is in the HIGH area,notify DS Maintenance to replaceair compressor.(b) If oil amount is in the LOW area,air compressor is OK.MEASUREMENT TESTTable 2-33.