Air Compressor Wont Build Pressure Past 40 PSI
Pressure problems are one of the most common issues that air compressor owners will experience. These types of issues will cause your air compressor to not work properly due to the lack of pressure that is needed to operate.
The main causes of an air compressor not building pressure past 40 psi are dirty filters, air leaks, faulty valves, and a damaged belt drive. All of these issues will cause pressure problems that will result in your air compressor not working properly.
This guide will provide more details on the causes of the issues and offer some ways that you can remedy them yourself. It is important that you address any pressure issues with your air compressor as soon as possible to avoid further damage or inconvenience.
Air Compressor won’t Build Pressure Past 40 PSI Causes
The main causes of an air compressor not building pressure past 40 psi are dirty filters, air leaks, faulty valves, and a damaged belt drive. All of these issues will cause pressure problems that will result in your air compressor not working properly.
The next part of this guide will provide more details on these issues as well as some other common causes of air compressor pressure problems. You should use this information to accurately identify your issue so that you can resolve it appropriately.
Dirty Filters
If your air inlet filter is dirty and clogged, this could cause your air compressor to have issues building up the appropriate amount of pressure to operate. Air filters used in your compression system will get dirty over time and should be cleared of buildup and debris periodically.
If you have not changed your air filters in a while, it is likely the cause of your pressure issues. It is recommended that you change the filters in your air compressor at least once a month. This can help you avoid significant buildup that could cause pressure issues.
Air Leaks
Air leaks in your compressed air system will also cause pressure issues. If the tank, hoses, or fittings that you are using in your setup have a leak, this will cause your compressor to be unable to buildup the proper amount of pressure to operate at full capacity.
Leaks are the most common causes of pressure issues with air compressors. It is estimated that air compressor systems that lack proper leak management waste up to 50 percent of their total air production.
Faulty Air Compressor Valves
If the valves in your compressed air system have leaks or connection issues, this will cause your air compressor to have problems achieving higher psi levels. There are circumstances where the inlet valve of your compressor could be jammed or your drain valve has not closed properly.
The most common valve issue that results in loss of pressure is a faulty reed valve. If your reed valve is damaged the pressure will not be routed correctly through your air compressor.
Faulty Belt Drive
If you have a belt-driven air compressor, a damaged belt drive could be the cause of your pressure issues. Belt-driven air compressors are extremely common and often encounter internal issues that cause them to become damaged or worn over time.
When the belt drive stops functioning optimally, it will cause the total pressure buildup of your air compressor to diminish over time.
Damaged Pump Rings
If the pump rings used to seal air into the cylinders of your air compressor are damaged or worn, this will cause you to experience low-pressure issues. Damaged pump rings will cause your compressor to be unable to efficiently compress and process air.
Faulty Motor Capacitor
If your motor capacitor is not functioning properly, it will cause power issues with your air compressor. When your air compressor is experiencing power issues, it will be unable to reach the higher psi levels that you would expect out of your system.
Damaged Air/Oil Separator
If the air/oil separator in your air compressor is clogged or damaged, this will cause air and oil to not be efficiently separated. When this happens, this will cause your air compressor to be unable to reach the pressure threshold properly.
Troubleshooting Methods
To troubleshoot your air compressor pressure issues, you should replace any damaged components and inspect any components that you believe to be functioning improperly. These troubleshooting methods will be discussed in detail in the section below.
Clean Or Replace Filters
You should clean or replace any seriously clogged or dirty air filters in your compressed air system.
It is advised that you replace the air filters in your air compressor at least once a month. That being said, they could need to be cleaned more frequently depending on the environment and frequency of use.
You can purchase a replacement filter online for around $12. The table below contains some of the most popular online vendors and their prices for air compressor filters. You should use this table to ensure that you are getting the best deal on your air compressor filters.
| Vendor | Avg. Air Compressor Filter Cost |
| Walmart | $10 |
| Amazon | $12 |
| Filter Element | $12 |
| Lowes | $10 |
| Home Depot | $10 |
Check For Leaks
You should inspect the hoses, tank, and fittings to ensure that there is no air leaking through. A visual inspection of your compressed air system is the best way to determine whether or not you have an air leak causing your pressure issues.
You should also tighten any air tube fittings and replace any hoses that have rips or damaged connector tips. If your tank has a leak, you should consider replacing it to restore your compressed air system to full functionality.
Check Air Compressor Valves
You should also check all of the valves in your compressed air system to ensure they are functioning properly. This includes making sure the inlet valve is able to open and close properly and ensuring that the drain valve is able to tightly seal.
You should also inspect the safety valve of your air compressor. If the safety valve is not functioning properly, your compressor will have no fallback in case the pressure switch fails to turn the compressor off once it reaches the maximum pressure threshold.
Replace Belt Drive
You should check the belt drive and ensure that it is not damaged and is functioning properly. To check the belt, you should first ensure that the air compressor is completely turned off and disconnected from the power source.
Once you have done this, remove the rear section of the belt guard and adjust the belt as necessary. The belt in your air compressor will wear over time so you will need to replace it if you find that it is beyond repair.
You can purchase a replacement belt online for around $20. The table below contains some of the most popular online vendors and their prices for air compressor belts. You should use this table to ensure that you are getting the best deal on your air compressor belts.
| Vendor | Avg. Air Compressor Belt Cost |
| Walmart | $18 |
| Amazon | $20 |
| Filter Element | $22 |
| Lowes | $20 |
| Home Depot | $16 |
Replace Pump Rings
You should inspect the pump rings used to seal the air in your compressor’s cylinders. If the pump rings have become worn, you should replace the pump rings. You can purchase new pump rings for your air compressor for around $5 each.
The table below contains some of the most popular online vendors and their prices for air compressor pump rings. You should use this table to ensure that you are getting the best deal on your air compressor pump rings.
| Vendor | Avg. Air Compressor Pump Ring Cost |
| Walmart | $3 |
| Amazon | $5 |
| Filter Element | $5 |
| Lowes | $7 |
| Home Depot | $6 |
Repair Motor Capacitors
You should inspect your motor capacitors and have them repaired by a certified electrician if you believe this is the cause of your pressure issues. A certified electrician can perform a full inspection of your air compressor and let you know for sure whether or not your motor capacitors need to be replaced.
As previously stated, you will need a certified electrician to confirm and repair motor capacitor issues. Attempting to repair the motor capacitor of your air compressor without the proper tools and experience could result in damage to your machine or yourself.
Replace The Air/Oil Separator
You should inspect the air/oil separator of your air compressor and replace it if you find that it is no longer functioning properly. You will need to reach out to the manufacturer of your air compressor for more information regarding the proper air/oil separator specifications for your machine.
Final Thoughts
This guide has provided you with all of the information that you need to accurately identify the cause of your air compressor pressure issues. If you are having issues with your air compressor not reaching past 40 psi, this guide can offer you troubleshooting methods that can help resolve these issues.
It is important that you address any pressure issues you are experiencing with your compressed air system as soon as possible. This will keep your air compressed from incurring more damage in the future.
