Air Dryer Filter

The function of the air dryer is to release moisture and air from the brake system which prevents it from going into the main system. When pressure has built up in the air system of the coach to reach its maximum set level, usually about 125 to 140 psi, the excess pressure is released from the air dryer which can be physically heard coming from the rear of the coach as the pressure is blown off when the maximum pressure in the system is attained. At this point, the front and rear pressure gauges will indicate the maximum pressure at which they are set to read (as indicated above).

There is a filter located on top of the air dryer that traps moisture and particulate matter from going into the air system that must be changed once a year in order to prevent too much moisture condensation from forming in the filter thereby clogging it and allowing this moisture into the main air system. This is especially important if traveling in areas where there exists high humidity. The high humidity creates even more condensation than normal, however yearly replacement will suffice so as to maintain a clean air dryer filtration system to operate normally.

Warning! Always consult with a professional RV mechanic, your owner's manual, and/or your authorized RV dealer BEFORE performing any maintenance procedures or brake safety inspections. The maintenance recommendations on this page are meant as general guidelines only. Failure to follow the manufacturer's specific recommendations and guidelines could result in serious injury or death. See 'Legal Disclaimer' below.

Changing the Filter

If the filter becomes clogged completely then particles from the filter can become released into the air system and become lodged in the braking mechanisms and this is absolutely not a good situation. So to avoid such problems, it is absolutely necessary to change the filter annually. The filter can be changed with the use of a large belt filter wrench or have it done professionally when annual service is performed on the coach.

One note of caution, before removing the old air dryer filter, it is necessary to release all of the pressure from the main pressure tank. This can be accomplished by fanning the brakes on the coach until the front and rear pressure indicators on the dash board read zero. One should then manually pull on the release lever of the main pressure tank that opens the drain valve which releases any air or moisture trapped in the bottom of the tank to confirm that the tank is indeed empty. If this is not performed prior to attempting to change the filter, the pressure in the system will blow the old filter sky high."

Legal Disclaimer & Caution: Before using any advice, and/or performing any maintenance procedures recommended on this website you should consult with your RV dealer, and/or a professional Motorhome or RV mechanic. The recommendations and advice given on this website are intended as general guidelines ONLY, and may not pertain to your particular make and/or model of RV or Motorhome. Use these suggestions, repair tips, and/or maintenance advice AT YOUR OWN RISK. Under no circumstances will this website, or any of its officers or employees be liable for any consequential, incidental, special or exemplary damages even if appraised of the likelihood of such damages occurring. The owners of this website do not warrant the information against errors, omissions or deficiencies of any kind.

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