Tools & Materials
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 valve plate assembly controls the flow of air through the compressor pump. It consists of a metal plate with thin metal valves mounted to it. Over time, these valves can chip or deteriorate. When this happens, the compressor will no longer build pressure properly.
Less than impressed with your compressor? Replacing the valve plate assembly may be the solution. This article will show you how to complete the repair with expert precision. 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 VALVE PLATE [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. FIX TRIX: Make note of the original wiring configuration to simplify installation in later steps.
Use long-nosed pliers to disconnect the front wire from the field.
Use a flat-blade screwdriver to disconnect the ground wire from the pump.
Partially extract the pump from the housing to expose the rear wire connections.
Use long-nosed pliers to disconnect the rear wire from the field.
Rotate and slide the pump assembly away from the housing.
6. Disassemble the pump.
Use a small socket wrench to loosen and extract the bolts from the cylinder head.
Remove the bolts from the cylinder head.
Separate the pump and internal components from the cylinder head.
REBUILDING THE PUMP [top] 7. Rebuild the compressor pump.
Align the new cylinder gasket (included) with the new valve plate assembly. (The gasket should be seated against the side of the valve plate that contains the exposed valves).
Align the new valve plate assembly (and cylinder gasket) with the compressor pump. (The cylinder gasket and the exposed valves should be facing the cylinder-side of the pump.)
Align the head gasket with the valve plate assembly.
Install the cylinder head.
Install the head bolts.
Torque the head bolts (in a crisscross pattern) to the specifications provided by the manufacturer of your specific manufacturer. (The torque specification for the Porter Cable compressor shown here is 49-55 inch-lbs.)
REASSEMBLING THE UNIT [top] 8. Reinstall the pump into the housing.
Partially install the pump 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]