• 100 PSI Max Rating, 120V, 4A
• Vehicle mount compressor ensures air brake system is properly pressurized for immediate truck departure from station
• Pressure switch regulated operation automatically senses low pressure in air system and restores proper pressure, preventing brake lock-up
• Pressure switch regulated operation
• No interference with engine mounted air compressor
• Factory set PSI actuation points: 75 "On", 95 "Off" with Adjustment differential 20 PSI
• Sealed ball bearings for long service life
• Compact size
• 2-year warranty
• Part # 091-9B-4 replaces part # 091-9B-1

The Auto Pump AC is a 120-volt 60 Hz shaded pole A.C. motor operating a single cylinder air compressor designed specifically for installation on vehicles with air brakes.  During long idle periods of the vehicle, when even the slightest seepage can cause an air brake system pressure to drop below the brake lockup pressure, the Auto Pump AC automatically starts to maintain the pressure. 

The Auto Pump AC motor is directly coupled to the compressor section eliminating all belts and pulleys and assuring long life and reliable operation. A heavy-duty pressure switch is adjusted to start the compressor when the system pressure drops below 75 PSI and stops the compressor when 95 PSI is attained. The startup pressure is field adjustable - the pressure differential between start up and stopping is fixed. The moisture trap provided permits routine draining of accumulated moisture in the Auto Pump output line.

Usually ships in 3 to 5 days