For 1990-2009 cars

1. Clamp a piece of 1/2 inch ID rubber hose over the fluid inlet end of the solenoid.
2. Connect a wire from one of the solenoid terminals to the negative terminal (ground) of the battery.
3. Apply compressed air to the rubber hose. Do not use air pressure in excess of 120 psi. Excessive pressure will not allow the solenoid ball check valve to seat properly.
4. Connect a wire from the other solenoid terminal to the positive terminal (12 volts) of the battery.
5. Observe air flow through the solenoid. Replace the solenoid if there is an air leak when the solenoid is energized.