Why is My Air Compressor Not Building Pressure?

Air compressors are reliable and essential pieces of equipment. No matter how reliable they are, even air compressors are prone to problems. So, what does it mean if your air compressor runs but doesn’t build pressure?

If your air compressor runs but doesn’t build pressure, it’s likely because there is a worn piston seal, faulty gasket, or damaged belt drive. Your air compressor also won’t build pressure if the air filter is clogged, and you must check it daily. Air compressors can’t build pressure if the capacitator is broken or if the intake valve is blocked and damaged as well.

Air compressors can easily last more than 25 years if you take great care of them. Regularly check the filter and oil level to avoid pressure problems. Follow along as we explore why your air compressor runs but doesn’t build pressure.

Why Won’t My Air Compressor Build Pressure?

Whether it be a clogged air filter, worn belt drive, or faulty gaskets, there are several reasons why your air compressor runs but doesn’t build pressure. Follow along as we explore some of the top reasons why your air compressor is not building pressure and see how you can fix it.

1. Clogged Air Filter

Check the filter right away if your air compressor runs but doesn’t build pressure. Most air compressor filters can last up to 2,000 hours, but it depends on usage and how often you clean them. Air compressors struggle to build pressure when the filter is clogged because the debris disrupts the airflow.

Not only will that slow down your workload, but it can also damage your air compressor. Inspect the air filter each day before you use the air compressor to make sure it’s not clogged. You can clean the filter with a brush or compressed air. However, you should keep track of how long the filter has been there so you can replace it at least once per year or every 2,000 hours of use.

2. Worn Piston Seal

The piston seal is an important part of an air compressor. It keeps oil and dust out of the air compressor, and that’s necessary for smooth operation. A worn piston seal can explain why your air compressor runs but doesn’t build pressure, and it’s an easy problem to fix.

Piston seals typically last for 2,000 to 8,000 hours of use, but the lifespan varies based on several conditions. For example, piston seals may wear out faster if your air compressor is in a humid environment with poor ventilation. Simply replace the piston seals if they are corroded or won’t fit tight so your air compressor will build pressure as usual.

3. Faulty Gaskets

Like piston seals, faulty gaskets can explain why your air compressor doesn’t build pressure. These seals are typically made of durable materials like Teflon and rubber, but they can still go bad. Gaskets seal the joints between the components of an air compressor.

Air can leak when the gaskets wear out, and the air pressure won’t build. High-end air compressor gaskets typically cost $50 or more, and it’s worth the cost to invest in gaskets made of premium materials. Simply replace faulty gaskets and inspect them for corrosion if your air compressor doesn’t build pressure.

4. Damaged Intake Valve

The intake valve is one of the most important components of an air compressor. This part controls the airflow and pressure, but it’s also quite susceptible to damage from excessive pressure and moisture. It’s easy to accidentally damage an intake valve if you cover it with another piece of equipment.

You must remove the intake port filter to see if the intake valve is damaged. Air will blow out of the intake port filter if the intake valve is damaged. Intake valve replacement kits typically cost $300 or more, but the valves themselves only cost $12 to $25 in many cases.  

5. Broken Pressure Pump Valve

The pressure pump valve controls how well your air compressor builds pressure. If it doesn’t build pressure, there’s a good chance that your air compressor has a broken pressure pump valve. Pressure pump valves often last just as long as the air compressors themselves, but they can break after a few years if you use the machine a lot.

Pay attention to the maximum air pressure level on your compressor. If the air pressure is lower than the maximum level and it doesn’t build pressure, that’s a sign the pressure pump valve is broken. You can manually replace this part, but it’s also worthwhile visiting a repair shop that specializes in air compressors if you don’t have much experience with them.

6. Worn Belt Drive

Many air compressors feature belt drives. Belt-drive air compressors are quite popular because they don’t run as loud as other types of compressors. The belt runs between the pump and the motor, and they can wear out over time.

When the belt wears out, pressure doesn’t build within your air compressor, and it essentially becomes useless. It’s just as important to check the belt each day as it is to check the oil filter in your air compressor. Luckily, you can replace the belt in an air compressor for just $8 to $20, so it’s not a big deal if it wears out.

7. Problematic Capacitator

If your air compressor runs but doesn’t build pressure, it may have nothing to do with the tank or inlet valve. The lack of pressure could simply be because the capacitator is damaged. Capacitators help the motor in an air compressor do its job.

This part can wear out over time from excessive use, lack of maintenance, overheating, and environmental conditions. For example, air compressors in hot and humid environments are more susceptible to corrosion and damage. This can affect everything from the capacitator to the pressure pump valve.

The breakers in your air compressor can trip if the capacitator is damaged or broken. Pressure doesn’t build when the breakers trip and you can’t use your air compressor. Turn off your air compressor, unplug it, let it cool down, and inspect the capacitator. That way, you can safely check for damage and replace the capacitator if you must.

8. Your Air Compressor is Overheated

Air compressors can overheat just like any piece of equipment. This can happen if you block the intake valve or simply place the air compressor in a hot and humid environment. An air compressor can run but doesn’t build pressure in overly hot environments, especially if the vents are clogged.

Never place your air compressor in a position where the vents are covered. Not only will this stop the compressor from building pressure, but it will also cause it to overheat. It’s also important to check the condenser coils on your air compressor because the machine can overheat if they become clogged.

9. Old Air Compressor

Air compressors have a long lifespan, and that makes them among the most reliable pieces of equipment. That said, nothing lasts forever, and even air compressors can wear out over time. You may simply need to replace your air compressor if it runs but doesn’t build pressure.

Air compressors can last 25 years or longer, but it ultimately depends on how well you take care of them. An air compressor can fail and wear out in as little as 5 years if you don’t maintain it. Check the oil levels daily, clean the filter, and make sure you don’t cover the air intake.

This will ensure that your air compressor lasts as long as possible. Industrial air compressors cost between $3,000 and $65,000, so it’s a great idea to take care of it so you don’t have to replace it for several decades.

How Fast Should an Air Compressor Build Pressure?

An air compressor can typically build pressure within 2 to 5 minutes. However, it ultimately varies between brands, air compressors, and the size of the tank. It takes longer to build pressure within a large tank than a small one.

For example, a 60-gallon air compressor can build pressure within 5 minutes, whereas a 20-gallon air compressor can build pressure within 20 minutes. Older air compressors won’t build pressure as quickly, especially if there’s a problem with the gaskets, filters, or valves.

So, Why Does My Compressor Run but No Air Pressure?

Check the filter if your air compressor runs but doesn’t build pressure. Clogged filters, worn piston seals, and faulty gaskets can cause air leaks which will stop your air compressor from building pressure. Your air compressor may run but won’t build pressure if the capacitator or belt drive is worn. Keep up with maintenance, inspect the pressure pump valve, and change the oil at least once per year to maintain consistent pressure.