There could be a couple of things wrong when your central pneumatic compressor refuses to build air pressure. It could be the pump gasket, failure of the pump piston, or it could be that air exits through the intake valve, If you are trying to troubleshoot the problem, here are some guides that can help you.
The reason why air pressure won’t build
The air compressor could be trying to build pressure, but it’s not possible because of a serious leak in the compressor. For a quick check, look at the valve on the tank drain. If the tank drain of the compressor is left open, ensure that you close the tank before starting the compressor. If not, the rate air drains out will be more than the rate it comes it. This will leave a major problem as the compressor may run but lacks any pressure. The solution? Change your pump and have it replace with another with the same model and make.
If you notice there is no major leak but air still leaks, albeit slightly, you can check any of the following.
Check the pump gasket
Gaskets are located at the upper side of your compressor with valve plates. The major function of the pump gasket is to make sure the incoming air is controlled within the lower region of the pump. Then the air moves through the pressure valve into the compressor tank.
Eventually, a portion of the gasket may start failing. This usually occurs with low-quality compressors with questionable fit and fittings. You may notice the problem when the compressor starts or when it reaches a particular tank pressure.
The pressure of the gasket may cause a breach. As a result, air will keep circulating from side to side but does not push into the tank. The compressor will run perfectly fine, but there is no pressure built within. In this situation, tearing down the pump should be the best thing to do. Then get the right pump rebuilt model for your type of compressor.
The rings on the pump piston are failing
This is another problem that may prevent your air compressor from building air pressure. If the piston ring fails, air can blow out consistently from the oil-filled tube. To troubleshoot this problem, you could initiate a teardown. As you do this, ensure that the interior of the cylinder is properly checked.
There shouldn’t be any damaged section as a result of metal contact of the worn rings on the piston. This should solve the problem. If this does not work and the air pressure still won’t build, you can try the next solution.
Air exits through the valve
If the pump intake blows out when pump still runs, it could be the problem from head pump valve. Whether it’s intermittent or consistent, as long as air goes out of the intake, it’s most probable failings of the valve.
In this case, the solution is to open the pump and take a look. Try to find a rebuilt part for the model and make of the compressor. You need to replace with the right make, as valves usually come with the rebuilt part. You shouldn’t try to fix the damaged valves. A replacement part will be ideal in this situation.
If you’ve tried the above solutions and the problem still persists, the next line of action is to call a technician for further assistance. But you should be able to fix the problem before you get to the part of calling an expert.