Sears 919.727121 owner manual Description of Operation, Tools Needed for Assembly

Air Compressor Pump: To compress air, the piston moves up and down in the cylinder. On the down- stroke, air is drawn in through the air intake valves. The exhaust valves remain closed. On the upstroke of the piston, air is compressed. The intake valves close and compressed air is forced out through the exhaust valves, through the outlet tube, through the check valve and into the air tank. Working air is not available until the compressor has raised the air tank pressure above that required at the air outlet.

Check Valve: When the air compressor is operating, the check valve is “open”, allowing compressed air to enter the air tank. When the air compressor reaches “cut-out” pressure, the check valve “closes”, allowing air pressure to remain inside the air tank.

Pressure Release Valve: The pressure release valve located on the side of the pressure switch, is designed to automatically release compressed air from the compressor head and the outlet tube when the air compressor reaches “cut-out” pressure or is shut off. If the air is not released, the motor will not be able to start. The pressure release valve allows the motor to restart freely. When the motor stops running, air will be heard escaping from the valve for a few seconds. No air should be leaking when the motor is running.

Pressure Switch: The pressure switch automatically starts the motor when the air tank pressure drops below the factory set “cut-in” pressure. It stops the motor when the air tank pressure reaches the factory set “cut-out” pressure.

Safety Valve: If the pressure switch does not shut off the air compressor at its cut-out pressure setting, the safety valve will protect the tank against high pressure by “popping out” at its factory set pressure (slightly higher than the pressure switch cut-out setting).

Regulator: The air pressure coming from the air tank is controlled by the regulator. Turn the regulator knob clockwise to increase pressure and counter-clock- wise to decrease pressure. To avoid minor readjust- ment after making a change in pressure setting, always approach the desired pressure from a lower pressure. When reducing from a higher to a lower setting, first reduce to some pressure less than that desired, then bring up to the desired pressure. Depending on the air requirements of each particular accessory, the outlet regulated air pressure may have to be adjusted while operating the accessory.

Outlet Pressure Gauge: The outlet pressure gauge indicates the air pressure available at the outlet side of the regulator. This pressure is controlled by the regulator and is always less or equal to the tank pressure. See “Operating Procedures”.

Tank Pressure Gauge: The tank pressure gauge indicates the reserve air pressure in the tank.

Cooling System: This compressor contains an advanced design cooling system. At the heart of this cooling system is an engineered fan. It is perfectly normal for this fan to blow air through the vent holes in large amounts. You know that the cooling system is working when air is being expelled.

•a 9/16" socket or open end wrench for attaching the wheels

•a 3/8" open end wrench or socket to tighten handle screws