How to Replace the Pressure Switch on an Air Compressor

If leaking seals and service bills are distressing your compressor, it's time to face the fix. While air compressors can be as diverse as the individuals that use them, most models share some general characteristics and components. Whether you are inflating your tires or creating empires, eReplacementParts.com provides the parts, procedures and facts you need to fearlessly fix what fails you.

The pressure switch is designed to activate the compressor motor at a pre-set pressure, and to de-activate the motor once that pressure has been reached. Common symptoms of a faulty pressure switch include a motor that continues to run (regardless of pressure) until the safety valve opens, or a compressor that simply will not turn on at all.

Less than impressed with your compressor? Replacing the pressure switch might be the solution. This article will show you how to complete the repair like an expert technician.   THE FACTS | THE FIX | THE FINISH ! DEPRESSURIZE THE AIR TANK.

Always depressurize the tank before servicing an air compressor. To do this, open the drain valve and wait until all of the air (and pressure) has escaped.

  REMOVING THE PRESSURE SWITCH  [top] 1. Remove the manifold cover.

Remove the retaining screw.

Lift the manifold cover away from the unit.

    2. Remove the pump assembly from the tank.

Remove the front retaining screw.

Remove the rear retaining screw.

Slide the pump assembly to the side.

Lift the pump assembly away from the tank.

Position the pump assembly upon the isolator feet a flat work surface.

    3. Remove the top handle.

Remove the two retaining screws.

Remove the top handle from the pump housing.

    4. Remove the rear pump housing cover.

Remove the three retaining screws.

Remove the rear pump housing cover.

    5. Remove the pump from the housing.

FIXTRIX: Make note of the original wiring configuration to simplify installation in later steps.

Use long-nosed pliers to disconnect the front (yellow) wire from the field.

Use a flat-blade screwdriver to disconnect the ground wire from the pump/motor.

Partially extract the pump/motor from the housing to expose the rear wires.

Use long-nosed pliers to disconnect the rear wire from the field.

Rotate and slide the pump assembly away from the housing.

    6. Remove the pressure switch.

Using heavy-duty wire cutters, cut and remove the connecting clamp from the hose.

Use hose-puller pliers to remove the hose from the manifold.

Remove the (red) switch wire from the pressure switch terminal.

Use a Torx driver to remove the pressure switch retaining screw.

Remove the pressure switch.

  INSTALLING THE NEW PRESSURE SWITCH  [top] 7. Install the pressure switch.

Install the hose-end of the pressure switch through the hole in the housing.

Secure the pressure switch to the housing with the new screw (included).

Reinstall the (red) switch wire to the pressure switch terminal.

SPECIFIX: Depending on your specific compressor model, the new hose may need to be cut to fit the existing manifold. Measure and cut the hose as necessary.

Slide the new hose clamp (included) over the end of the new hose.

Reconnect the hose to the manifold inlet.

Use end-nip pliers to crimp the tabs of the connecting clamp and  secure the hose.

     REASSEMBLING THE UNIT [top] 8. Reinstall the pump/motor into the housing.

Partially install the pump/motor into the housing.

Reconnect the rear (white) wire to the field terminal. 

Align the feet on the compressor pump with the grooves in the housing and slide the pump fully into position within the housing.

Reconnect the front (yellow) wire to the field terminal.

Reconnect the ground (green) wire to the pump and secure it with the screw.

    9. Reinstall the rear housing cover.

Install the rear portion of the pump housing.

Secure the housing cover with the three screws.

    10. Reinstall the top handle.

Install the top handle to the pump housing.

Secure the top handle with the two screws.

    11. Reinstall the pump assembly.

Align the entire pump assembly with the compressor tank.

Slide the pump assembly into place upon the isolator feet.

Secure the pump to the tank with the rear mounting screw.

Secure the pump to the tank with the front mounting screw.

    12. Reinstall the manifold cover.

Install the manifold cover.

Secure the manifold cover with the screw.

  THE FACTS | THE FIX | THE FINISH

A well-maintained air compressor can mean the difference between performance under pressure, and under-pressured performance. But you don't have to empty your pockets to keep your air tank full. As you just learned, repairing your air compressor is simpler than you think, especially when you follow our step-by-step guides. Not only did you refresh compression at a fraction of the cost of replacement; you have inflated your ability to fearlessly face the next fix, regardless of the pressure involved. Find your next fix here.   [top]