Air Compressor Installation Instructions{1803} Caterpillar

Caterpillar Products: Equipped with Air Compressors

Do not perform any procedure in this Special Instruction until you read this information and you understand this information. Do not perform any procedure in the Air Compressor Service Manuals until you read the information and you understand the information. Use only proper tools and observe all precautions that pertain to the use of those tools. Failure to follow these procedures can result in personal injury and premature failure of the air compressor. The following procedures should also be observed.

1. Park the vehicle on a level surface. Engage the parking brake. Block vehicle wheels. Tag the ignition switch for the engine with a "Do Not Run" tag.

2. Purge all pressurized components, reservoirs, and lines to zero pressure. Do not disconnect any pressurized components or do not remove any pressurized components until the pressure is zero.

3. Never exceed the recommended air pressure or fluid pressure. Always wear safety glasses when pressurized systems are being worked on.

4. Inspect all air lines, coolant lines, oil lines, and governor lines for the following conditions prior to installation:
   • Crimped lines

   • Other flow restrictions

   • Corrosion

   • Additional damage

   Clean the lines or replace the lines.

Installation of the Air Compressor

1. Mounting

   Note: Refer to the following applicable publications for complete specifications:

   • Engine service manual

   • Vehicle service manual

   • Air compressor service manual

   • Governor installation

   • Air dryer circuit

   • Special instructions

   1. Remove all thread protectors from the air compressor. Make sure that no dirt particles enter the passages. Clean all mating surfaces of the air compressor and the engine before the gaskets are installed.

   2. Install either of the following drive mechanisms. This is dependent on the type of drive for the air compressor that is being installed.
      • Pulley

      • Accessory drive gear

      • Spline coupling

      Inspect the drive mechanism for visible wear or damage.

      Repair the suspect parts or replace the suspect parts.

      Tighten the retaining nut to the torque that is specified in the applicable Air Compressor Service Manual.

   3. A new gasket should be used when the compressor is installed on the engine. Do not use gasket sealant. Check for proper alignment of the air compressor crankshaft and drive components before final tightening of bolts. Tighten the mounting hardware to the torque that is specified in the applicable Air Compressor Service Manual. Use 9S-3263 Thread Lock Compound on mounting bolts. Some large air compressors require an additional support bracket and attachment hardware due to increased length and weight.

      Note: The maximum pulley offset is 76.2 mm (3.00 inch) on arrangements for air compressors that are driven by a pulley. When the drive belt is tightened, do not exceed 1068 N (240 lb) of radial force on the crankshaft. Excessive force on the crankshaft could result in shorter bearing life and/or a broken crankshaft.

   4. Install the inlet manifold or the fitting and install the exhaust fitting to the compressor. Use new gaskets or seals. Do not use sealant.

2. Governor

   Note: Make sure that the governor exhaust port is open to the atmosphere.

   Install the following components:

   • Governor

   • Line from the air reservoir to the governor

   • Line for the governor unloader to the air compressor

   Note: The unloader line for the governor is not required if the governor is directly mounted to the compressor.

   Note: Some models of air compressors may use a single governor or use more than one governor. All air compressors must have governors that are correctly installed. Damage to the air compressor or damage to the air system components may result if the air compressor is incorrectly governed. Consult the installation instructions on the specific air compressor for your application.

   Use new gaskets. Do not use gasket sealant.

   Tighten the mounting hardware to the torques that are specified in the applicable Air Compressor Service Manual.

3. Air Inlet

   1. The air compressor should never be used without a filter on the air inlet. Inspect the following filters:
      • Filter for the engine air inlet

      • Filter for the compressor air inlet

      Replace the filter if the filter is dirty or damaged. A dirty filter or a restricted filter will affect performance. The restricted conditions may cause the air compressor to exhaust an excessive amount of oil. Refer to the applicable Parts Manual for the appropriate air filter.

   2. Install the air inlet line to the inlet manifold for the air compressor or the fitting. Tighten the fittings to the torques that are specified in the applicable Air Compressor Service Manual.

4. Air Discharge

   1. The line for the air discharge must be installed with the following conditions:
      • Bends must be a minimum of a 51 mm (2.0) radius.

      • Be free of traps.

      • Tilt downward toward the air reservoir or the air dryer.

   2. Install the line for the air discharge to the fitting for the air compressor discharge. Tighten the mounting hardware for the discharge line to the torques that are specified in the applicable Air Compressor Service Manual.

5. Coolant Lines

   Install the coolant inlet line and install the coolant outlet line. The fitting for the coolant inlet should be installed at one end of the cylinder block or the cylinder head. This is dependent on the type of air compressor that is being installed. The outlet should be at the opposite extreme end of the cylinder head. The inlet port and the outlet port may also be specified in the applicable Air Compressor Service Manual. Tighten the fittings for the line connections to the torques that are specified in the Air Compressor Service Manual.

6. Oil Feed Line

   Note: An air compressor may be self-lubricated or the compressor may be lubricated by the engine lubrication system.

   Perform the following tasks for Self-lubricated compressors:

   • Install the oil drain plug.

   • Fill the crankcase for the air compressor with clean engine oil. Refer to the applicable Air Compressor Service Manual for the correct oil capacities. Use the port for the oil level dipstick in order to add oil. Use the oil level dipstick in order to check the oil level.

   Perform the following tasks for compressors that are lubricated by the engine lubrication system:

   Install the line for the oil feed. Some air compressors have two oil inlet ports in the rear end cap. The port that does not have a connection to the oil supply line must be plugged with a metal plug. Tighten the fittings to the torques that are specified in the applicable Air Compressor Service Manual.

7. Oil Drain Line

   Perform the following tasks for air compressors that are lubricated by the engine lubrication system only. This does not include compressors that are drained through the mounting flange.

   1. The line for the oil drain must be installed with the following conditions:
      • Bends must be a minimum of a 51 mm (2.0) radius.

      • Be free of traps.

      • Have a continuous downward flow and enter the engine above the engine oil level.

      The drain for the compressor should not be connected to any other oil drains. This could restrict the flow of oil out of the air compressor.

   2. Check the oil drain hole in the engine flange that mates with the oil drain hole in the compressor. Look for contamination or restriction.

   3. Install the oil drain line. Tighten the fittings to the torques that are specified in the applicable Air Compressor Service Manual.

8. Operational Test for the Air Compressor

   1. Ensure that the following items are checked before starting the engine.
      • All air, coolant, and oil lines are installed.

      • All ports on the air compressor are plugged.

      • All of the drain lines for the air system and the lubrication system are connected.

      • All fittings are tightened to the proper specification in order to prevent leakage.

      • All of the mounting hardware and brackets for the air compressor are tightened.

      • The engine coolant is at the proper level.

   2. Start the Engine.

      Note: A compressor may accumulate oil on top of the piston due to handling during storage and shipment. If this condition exists, disconnect the line for the air discharge. Start the engine and allow any trapped oil to be blown out of the compressor. Run the engine until the oil is purged. Shut off the engine and connect the discharge line to the compressor. Initial discharge of oil does not indicate an "oil passing" compressor.

   3. Inspect all connections and lines for air, coolant, or oil leakage. Listen for any noise which may indicate any of the following conditions:
      • Loose mounting of the compressor

      • Loose mounting of the lines

      • Misalignment of the drive gear

      • Misalignment of the pulley

   4. Observe the following items while the air pressure is built up to the governor cutout pressure. This is also referred to as the maximum system pressure.
      • Connections for the governor

      • Functions of the compressor unloader

      Now, reduce the pressure to the governor cutin pressure (minimum system pressure). Refer to the applicable Air Compressor Service Manual for the proper value for the governor cutout pressure and the proper value for the governor cutin pressure.

   5. Inspect any auxiliary air equipment and inspect any auxiliary lines for proper operation. Test this equipment and lines. Refer to the following publications for the operational measurements.
      • Engine service manual

      • Vehicle service manual