Air Compressor: Air leaks

Tighten air tube fittings where air escapes and replace any damaged air tubes. The check valve prevents tank air from back flowing to the pump and unloader. If air leaks out the unloader when the pump stops, replace the check valve because the check valve leaks air back towards the unloader. 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. Replace the air compressor tank if it leaks air. Rebuild the air compressor pump if it leaks air through the pump head when the pump runs because a broken valve plate seal is allowing air to escape through the pump head.

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 check valve

Replace the air compressor check valve

The check valve prevents tank air from back flowing to the pump. A failed check valve will apply high air pressure to the head of the pump preventing the motor from restarting once the tank has filled. If the motor starts when the tank is empty of air but won't restart when the tank is full, replace the check valve.

How to replace an air compressor check valve

If your air compressor won't restart after the tank fills, the check valve might be the problem. This DIY repair guide and video explain how to replace an air compressor check valve in less than 15 minutes.

Repair difficulty
Time required
 15 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 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.

Replace the air compressor unloader

Replace the air compressor unloader

The unloader opens to release pump head pressure when the air compressor stops, enabling the compressor to restart easier. Replace the unloader if it leaks air constantly or doesn't work correctly.

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.

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.