Cooling

Discharge	Optional “Ping” Tank
Line	Air Dryer

Compressor

Governor

(Governor plus Synchro valve for the Bendix® DuraFlo™ 596 Compressor)

The Air Brake Charging System supplies the compressed air for the braking system as well as other air accessories for the vehicle. The system usually consists of an air compressor, governor, discharge line, air dryer, and service reservoir.

Optional Bendix® PuraGuard ® QC™

Oil Coalescing Filter

Service Reservoir

(Supply Reservoir)

Reservoir Drain

FIGURE 12A - SYSTEM DRAWING

HOLE

THREAD

FIGURE 12B - DISCHARGE LINE SAFETY VALVE

The air dryer contains a filter that collects oil droplets, and a desiccant bed that removes almost all of the remaining water vapor. The compressed air is then passed to the air brake service (supply) reservoir. The oil droplets and the water collected are automatically purged when the governor reaches its "cut-out" setting.

For vehicles with accessories that are sensitive to small amounts of oil, we recommend installation of a Bendix® PuraGuard® QC™ oil coalescing filter, designed to minimize the amount of oil present.

Tu-Flo®400, 500 or 1000 compressors may be air-cooled or water- cooled and in some instances will have air-cooled blocks and water-cooled heads. The air-cooled versions are easily recognized by the external fins. The water-cooled versions are cooled by vehicle coolant.

PREVENTIVE MAINTENANCE

Regularly scheduled maintenance is the single most important factor in maintaining the air brake charging system. Refer to Table A in the Troubleshooting section for a guide to various considerations that must be given to the maintenance of the compressor and other related charging system components.

If the compressor is a self-lubricated type, its oil level should be checked daily. The oil level should be kept between the bottom of the dipstick threads and the bottom of the dipstick (Fig. 13). Every 8,000 miles or 300 operating hours, the oil should be drained and refilled with SAE 10-20-30.

FIGURE 13 - OIL LEVEL - SELF-LUBRICATED

COMPRESSOR

POLYURETHANE SPONGE STRAINER (Fig. 14)

Remove and wash all of the parts. The strainer element should be cleaned or replaced. If the element is cleaned, it should be washed in a commercial solvent or a detergent and water solution. The element should be saturated in clean engine oil, then squeezed dry before replacing it in the strainer. Be sure to replace the air strainer gasket if the entire air strainer is removed from the compressor intake.