Air Dryer Checking Procedures
Important: Review the warranty policy before performing any intrusive maintenance procedures. An extended warranty may be voided if intrusive maintenance is performed during this period.
Because no two vehicles operate under identical conditions, maintenance and maintenance intervals will vary. Experience is a valuable guide in determining the best maintenance interval for any one particular operation.
Every 12 months:
- Check for moisture in the air brake system by opening reservoir
drain valves and checking for presence of water. If moisture is present,
the desiccant cartridge may require replacement; however, the following
conditions can also cause water accumulation and should be considered
before replacing the desiccant:
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An outside air source has been used to charge the system. This air did not pass through the drying bed.
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Air usage is exceptionally high and not normal. This may be due to high air system leakage.
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In areas where more than a 30-degree range of temperature occurs in one day, small amounts of water can temporarily accumulate in the air brake system due to condensation. Under these conditions, the presence of small amounts of moisture is normal.
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- Visually check for physical damage, such as chaffed or broken air and electrical lines and broken or missing parts.
- Check the mounting bolts for tightness. See Table for torque values.
- Perform the operational and leakage tests listed below.
Note: A small amount of oil in the system is normal and should not be considered as a reason to replace the desiccant cartridge. Some oil at the dryer exhaust is normal.