Yep, the bottom one is the tag air pressure regulator. It should only let air out when the pressure in the tag axle is greater than the setting on the regulator. The tag pressure is typically set for 20-25 psi. Pulling out on the knob and rotating it should adjust the pressure. If the air pressure is in the range of 20-25 psi and rotating the knob does not result in stopping the flow of air (or increasing the flow of air if the knob if moved toward a low pressure) then the pressure regulator valve is likely defective. If it is stuck, it will continuously bleed off air pressure.
|