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375 Caterpillar Standard and Aftercooled/Filtered Operator’s Manual and Parts List
SECTION 7
Aftercooled And Filtered Air System, Functional Description ........................ 24
3 - SPECIFICATIONS ......................................................................................... 25
Specications – 300HH and 375 Caterpillar ................................................. 25
Specications – 375H and 425 Caterpillar .................................................... 26
Lubrication Guide – Compressor .................................................................. 28
Application Guide .......................................................................................... 28
Lubrication Guide – Engine ........................................................................... 28
4 - GENERAL ...................................................................................................... 29
General ......................................................................................................... 29
Purpose Of Controls ..................................................................................... 29
Control or Indicator Purpose ................................................................... 29
Initial Startup/Shutdown Procedure .............................................................. 30
Startup .................................................................................................... 30
Shutdown ................................................................................................ 30
Restart Procedure ......................................................................................... 30
5 - MAINTENANCE ............................................................................................. 31
General ......................................................................................................... 31
Daily Maintenance ........................................................................................ 31
Maintenance After Initial 50 Hours Of Operation .......................................... 32
Maintenance Every 50 Hours ........................................................................ 32
Maintenance Every 100 Hours ...................................................................... 32
Maintenance Every 250 Hours ...................................................................... 32
Maintenance Every 1500 Hours .................................................................... 32
Part Replacement And Adjustment Procedures ............................................ 33
Compressor Fluid Change Procedure .................................................... 33
Compressor Fluid Filter Element Replacement ...................................... 33
Air Filter Maintenance  ............................................................................ 33
Air Filter Replacement ............................................................................ 33
Element Inspection ................................................................................. 34
Separator Element Replacement ........................................................... 34
Procedure For Setting Speed And Pressure Controls On Portable 
Compressors Equipped With Poppet Valves  ......................................... 34
Bearing Lubrication ................................................................................. 36
First and Second Stage Discharge Air Filter Maintenance – Aftercooled & 
Filtered Models ....................................................................................... 37
Trouble Shooting ........................................................................................... 38
6 - NOISE CONTROL ......................................................................................... 43
Noise Emissions Warranty ............................................................................ 43
Tampering with the Noise Control System is Prohibited ............................... 43
Noise Emission Maintenance and Maintenance Record Log ................. 44
Noise Emissions Maintenance and Maintenance Record Log ...................... 44
Procedure For Ordering Parts ....................................................................... 47
7 - ILLUSTRATIONS AND PARTS LIST ............................................................ 47
Recommended Spare Parts List ................................................................... 49
Engine, Compressor And Parts ..................................................................... 50
Radiator & Compressor Fluid Cooling System ............................................. 54
Air Inlet System & Exhaust System .............................................................. 58
Control Parts & Discharge Parts - 375 and 425 ............................................ 60
Control Parts & Discharge Parts - 300HH and 375H .................................... 64
Regulator/Blowdown Valve - 375 And 425 .................................................... 68
Regulator/Blowdown Valve - 300HH and 375H ............................................ 70
Control Parts Orice - 300HH and 375H ....................................................... 72
Service Valves............................................................................................... 74
Optional AfterCooler/Filter And Parts ............................................................ 76