How does a Bendix AD 9 air dryer work?

The function of the AD-9™ air dryer is to collect and remove air system contaminants in solid, liquid and vapor form before they enter the brake system. It provides clean, dry air to the components of the brake system which increases the life of the system and reduces maintenance costs.

When should I replace my air dryer cartridge?

Depending on how you drive the truck and how much air you consume, you might replace a cartridge like this every two or three years. More frequent replacement might be required if the compressor passes a lot of oil or the truck is used for vocational service.

How often should a Bendix air dryer purge?

Air Tanks and Purge Valves Up to once a month for vehicles with high air demand or every three months for a typical line haul truck is recommended.

What does a purge valve on an air dryer do?

The purge cycle of the air dryer begins when the governor causes the compressor to unload (stop compressing air). During compressor unload, the line connecting the governor unloader port to the AD-9 air dryer end cover control port is pressurized. The air pressure causes the air dryer purge valve to open.

Why does my air dryer keep popping off?

Check for air leaks in the line between the air governor and the drier pop off valve. This should be the center tap in the governor. if it is an ad-9 drier and it leaks through the purge valve after its initial main purge and doesn’t stop till it is back on the build cycle check the check valve in the discharge port.

What causes an air dryer to keep popping off?

How do I know if my air dryer is bad?

Here are some of the signs that you may need to replace or repair your air compressor or dryer.

  1. Your Compressor Won’t Start.
  2. Your Compressor Won’t Stop.
  3. You Hear Odd Noises From the Compressor.
  4. You Have Circuit Breaker Problems.
  5. Your Compressor Shakes or Makes Ticking Noises.
  6. Your System Blows Warm Air.

What causes air dryer to keep popping off?

What does a purge valve solenoid do?

The canister purge solenoid — also referred to as an EVAP canister valve — is responsible for “purging” the EVAP system by acting as the switch that allows the vapor into the engine. When the purge solenoid fails, it will cause problems for the EVAP system, which will affect the vehicle’s emissions output levels.