Air Compressor: Won't build tank pressure

Shut the drain valve at the bottom of the tank if it's open. Check for air tank leaks and replace the tank if it's leaking. Tighten loose air tube fittings to prevent air leaks. The safety valve pops open to relieve excessive air pressure if the pressure switch fails to shut off the air compressor at the cut-out pressure setting. Replace the safety valve if it leaks air constantly. Worn pump seals prevent the pump from compressing air. If the pump won't compress air, rebuild the pump. The valve plate regulates airflow into and out of the pump cylinder to compress air, so replace the valve plate if damaged.

air compressor

These repairs may help solve your air compressor problem

Rebuild the air compressor pump

Rebuild the air compressor pump

Worn pump parts and seals prevent the pump from compressing air. If the pump won't compress air, rebuild the pump with new parts and seals.

May 1, 2015
By Lyle Weischwill
How to rebuild an air compressor pump

If your air compressor's gauges show that the tank isn't building pressure, the pump might be the problem. This DIY repair guide and video show how to rebuild an air compressor pump with step-by-step instructions.

Repair difficulty
Time required
 45 minutes or less
Read more
Replace the air compressor valve plate

Replace the air compressor valve plate

The valve plate regulates airflow into and out of the pump cylinder to compress air. Replace the valve plate if damaged.

May 1, 2015
By Lyle Weischwill
How to rebuild an air compressor pump

If your air compressor's gauges show that the tank isn't building pressure, the pump might be the problem. This DIY repair guide and video show how to rebuild an air compressor pump with step-by-step instructions.

Repair difficulty
Time required
 45 minutes or less
Read more
Tighten air compressor air tube fittings

Tighten air compressor air tube fittings

Inspect air tube fittings regularly. Firmly tighten any leaking air tube fittings.

May 1, 2015
By Lyle Weischwill
How to rebuild an air compressor pump

If your air compressor's gauges show that the tank isn't building pressure, the pump might be the problem. This DIY repair guide and video show how to rebuild an air compressor pump with step-by-step instructions.

Repair difficulty
Time required
 45 minutes or less
Read more
Replace the air compressor safety valve

Replace the air compressor safety valve

The safety valve pops open to relieve excessive air pressure if the pressure switch fails to shut off the air compressor at the cut-out pressure setting. Replace the safety valve if it leaks or pops open at normal operating pressure.

Replace the air compressor tank

Replace the air compressor tank

Don't try to fix a leaking air compressor tank. Replace the tank if it leaks air.

Replace the air compressor air tubes

Replace the air compressor air tubes

Air tubes carry compressed air from the pump to the tank and from the tank to the outlet supply fitting. Replace air tubes if damaged or leaking.

Symptoms common to all air compressors

Choose a symptom to see related air compressor repairs.

Main causes: lack of electrical power, check valve failure, bad pressure switch
Main causes: rusted air tank, loose air tube fitting connections, bad check valve, leaky safety valve, bad tank drain valve
Main causes: bad safety valve, pressure switch failure
Main cause: faulty output air pressure regulator
Main causes: tank drain valve open or leaking air, leaky air tank, bad safety valve, worn pump seals, bad pump valve plate
Main cause: bad air tank pressure gauge
Main causes: loose air tube fitting connections, bad check valve, faulty safety valve, damaged or corroded air tank, bad air pump
Repair guides common to all air compressors

These step-by-step repair guides will help you safely fix what’s broken on your air compressor.

May 1, 2015
By Lyle Weischwill
How to rebuild an air compressor pump

If the air compressor won't fill the tank with compressed air, rebuild the pump using these steps in about 45 minutes.

Repair difficulty
Time required
 45 minutes or less
How to replace an air compressor pressure switch

You can replace a broken air compressor pressure switch in about 45 minutes.

Repair difficulty
Time required
 45 minutes or less
How to replace an air compressor check valve

You can replace a defective air compressor check valve in about 10 minutes.

Repair difficulty
Time required
 15 minutes or less
Articles and videos common to all air compressors

Use the advice and tips in these articles and videos to get the most out of your air compressor.

May 1, 2015
Air compressor common questions
By Sears PartsDirect staff

These answers to common questions can help you make the most of your air compressor.

April 24, 2015
How to reduce air compressor noise
By Sears PartsDirect staff

Find out how to reduce air compressor noise.

April 22, 2015
The unseen dangers of air compressors
By Sears PartsDirect staff

Learn about the possible dangers associated with using an air compressor and how you can reduce the risks of property damage and personal injury.