B5.9G, B5.9LPG – Troubleshooting and Repair Manual – 012-014   Air Compressor

• Steam clean the air compressor and dry with compressed air.
• Drain the engine coolant if the air compressor has a liquid cooled cylinder head. If compressor is air cooled, then the engine coolant need not be drained.
• Open the draincock on the wet tank to release air from the system. Close the draincock after the pressure is released.

Remove the air connections from the air compressor.

15/16-Inch, 7/8-Inch

Remove the coolant lines from the air compressor (does not apply to air cooled compressors).

9/16-Inch

Remove the oil supply line.

15/16-Inch

Remove the oil return line from the bottom of the air compressor.

18 mm, 14 mm, 10 mm

Remove the air compressor support bracket and capscrews.

Remove the air compressor mounting nuts.

Remove the air compressor.

Visually inspect the compressor housing for cracks or damage.

Visually inspect the drive gear for cracks or damaged.

Be sure the gasket surfaces of the gear housing and air compressor are clean and not damaged.

Power Steering Coupling (if applicable)

Inspect the coupling for wear or cracks.

Replace the coupling if damaged.

Power Steering Adapter

Inspect and replace the adapter if any damage is found.

Air Compressor Timing (for single cylinder air compressor only)

Locate TDC on the compressor crankshaft by removing the unloader valve or head, (refer to the (respective) air compressor manual). TDC does not have to be exact. The system is tolerant of some misalignment.

Use ink or dychem to mark the air compressor gear face at TDC (12:00 o’clock position when viewed from the front).

The following method does not require any reference marks and can begin with any cylinder This method will work on any four-cycle engine.

Follow the sequence shown to set the valve on a six cylinder engine.

Rotate the compressor TDC mark to 60 degrees, or 6 teeth on a 36 tooth gear, before TDC. This is approximately 10:00 o’clock when viewed from the front of the air compressor.

NOTE: Holset® air compressors Series SS, QE220, 296 and 338 will have a radial line etched on the gear representing TDC.

18 mm, 14 mm, 10 mm

Use a new gasket. Install the air compressor to the gear housing.

Install the air compressor support bracket.

NOTE: No timing of gears is necessary.

9/16-Inch

Install the oil supply line.

15 mm

Install the oil drain to the bottom of the compressor.

15/16-Inch, 7/8-Inch

CAUTION  If rubber grommets are used on the coolant or air lines, be sure they are installed carefully to prevent cuts or tears to the grommets which will cause leaks.

Install the coolant lines.

Install the air lines.

Fill the engine cooling system (liquid cooled air compressor only).

Operate the engine and check for leaks.

Operate the engine to activate the air compressor.

With the air compressor pumping between 550 to 690 kPa [80 to 100 psi], use a solution of soapy water to check for air leaks.