Thanks for the advise... I have Viton o-ring on the way. Also, I spoke with a MaxAir rep today and I got what I think is some pretty good advise. I jotted down some notes while he was talking. ...hope I didn't miss anything. Here is a copy of my notes:
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The MaxAir 90 Compressor holds 1.9 Liters of Oil
Small amount of oil (droplets) in bottom of filter cartridge chamber is normal. If more than just a few drops of oil are found at the bottom of the chamber then bad rings.
How to tell if the compressor ran hot:
1. Burned oil is found at the bottom of the filter chamber (or elsewhere).
2. If you rub the oil between your thumb and finger and you feel grit.
When replacing filters do not leave assemblies open for very long. Even small amounts of debris can greatly shorten compressor life.
Change main filter cartridge every 50 hours. Be sure to bleed air from bottom of assembly before removing plug. If you don’t, plug threads could be damaged. Plug should be put on snugly but not too tight. You should almost be able to remove the plug by hand by using thumb and a finger on two Allen head bolts. Be sure to use silicon grease on o-rings and threads. Silicon grease only and do not use silicon grease that comes in a spray can
Intake filter … When rotating or replacing, clean inside housing with a damp cloth, check for corrosion
Other filter / screen: Near the oil drain at back right you’ll find two solenoids, a black one and a silver one. The silver one has a filter that that needs to be periodically cleaned or replaced.
Clean valves at 1000 hours
Replace valves at 2000 Hours
Re-ring machine at 3000 hours (If cylinder walls still show crosshatching the re-ringing may not be necessary
To check compressor:
1. Hook up aluminum 80 tank and pump 500 pounds into it.
2. Close aluminum 80 tank valve.
3. With aluminum 80 tank valve closed, pump up compressor until pressure reaches 3000 PSI (fills internal compressor lines, components, etc.)
4. Open valve on aluminum 80 tank. If compressor is good it should take about 7.5 minutes to fill the tank.
To check if compressor needs to be re-ringed:
1. With compressor off and all pressure bled (bleed valve below filter cartridge)
2. Remove filter cartridge
3. Use lint free cloth on a rod to swab /clean out bottom of filter assemble
4. Replace filter
5. Carefully clean plug and threads
6. Clean O-rings
7. Apply silicone grease to the threads and o-rings. Use silicon grease only! Do not use silicon grease that comes in spray can.
8. Replace plug
9. Run compressor for 5 minutes
10. Purge pressure
11. Remove filter cartridge and inspect bottom of filter assembly
If assembly has oil collected in it then the rings are bad. Note – a few droplets of oil will be normal to see when the filter is changed after 50 hours.
