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Air System Maintenance Comparison





ClearDrain vs. Air Dryers

Installed ClearDrain System (7.2 pounds)   Installed Dual Air Dryer System (100+ pounds)


When spec’ing/purchasing air dryers-even with manufacturer and/or volume discounts-it should be understood that this is an initial cost only and not the total cost expended.  Air dryers require add-on(s), servicing and parts replacements. Manufacturers and parts distributors refer to this as “after market sales.”  When contamination gets beyond your dryer, air system components will require premature replacement.


Are you carrying the inventory cost to replace contaminated parts? Consider the cost of carrying inventory for components such as air valves, diaphragms, fan clutches, maxi-brake chambers etc. – these are replaced a majority of the time due to contamination and not wear!  Typical examples are air valves.  Rarely will an air valve require replacement due to wear.  Almost every fleet replaces them because of contamination resulting in slow valve application.  Also sticking valves lead to air system imbalance which results in premature component wear of brake shoes, drums etc. 

As reported in Fleet Equipment magazine (June/1990) in an article on Brake Balance (a study conducted by engineering teams from Freightliner, Great Dane & Rockwell International) concluded that in attempting to achieve Pneumatic Balance "A variation of one psi causes a 30% difference in the brake torque at the wheels.  Valves can slow down and fail due to air contaminated with water and oil vapor".  Among their conclusions, "Roughly, a two-psi pressure differential in relay valves resulted in the vehicles having one-half the lining life."

Air dryers must be serviced manually.  Desiccant, filters and/or parts need replacement if not semi-annually, then annually.  They are marginally effective at best and do not prevent ultimate contamination of air system components.  The savings which dryers were supposed to create continue to generate on-going expense.

  • Do you know the Total Cost of your air dryer(s) over its life cycle within your fleet?  Unless you’re using a software program to track components and costs closely, it may only be a guess!
  • How often do you rebuild, repair your dryers(s) and/or replace the core cartridge?
  • What is the warranty period of the dryer and the parts you’ve replaced?  Are they pro-rated?
  • Do you track warranties and are they being honored without any problems?



ClearDrain meets the need for air system today and the options that the industry demands – protecting ABS, air suspension, central tire inflation systems, etc.  There are no after-market costs with ClearDrain.  It is self-cleaning, self-defrosting, self-lubricating and offers continuous air system Preventative Maintenance with ignition control.  ClearDrain has been designed and engineered to be virtually maintenance-free!  Its dual function features:
  • Once every 15 minutes ClearDrain will expel contamination from the wet tank for a full five (5) second period.  This very specific time period and duration of purge cycle has been found to provide ample time for warm air and oil vapor to recondense in the wet tank and be expelled.  This insures nothing gets passed the wet tank.
  • At ignition shut-off ClearDrain will automatically open and drain the wet tank and the line completely back to the compressor to “O” psi.  This not only complies with The Maintenance Council’s recommended procedure of fully draining the wet tank but also insures that any moisture formed after shut-down will drain out from the compressor to the wet tank thereby preventing backpressure, carbon build-up, excessive compressor wear, super-heating of oil vapor and freeze-ups.  Additionally, if the trailer marries-up to the tractor ClearDrain will protect the air system of the trailer as well!

Within 3-4 weeks of installation, ClearDrain has prevented the wettest of vehicles and pneumatic equipment from further contaminating the air system.  Not only do the 2nd and 3rd air tanks remain clean and dry but also so do all air valves, diaphragms, maxi-brake chambers, fan clutches and other air system components.  Our clients report the elimination of brake drag due to sticking valves, greatly improved brake balance, extended brake shoe life and reduced drum wear! 

ClearDrain accomplishes this with one solid-state system,
weighing a mere 7.2lbs!


What is the difference between Total Cost and Initial Cost?

Total Cost represents the entire amount that will be spent for an item or product over the warranty period or its useful life.  Initial Cost pertains only to the original cost incurred; to this must be added subsequent labor, parts and vehicle downtime for components affected by that device.  Some industry analysts comment that the Initial Cost is merely an ongoing down-payment.

Initial Costs Expanding to Further Support Air Dryers!

Some air dryer manufacturers have now begun to admit that one dryer is not sufficient for certain air brake applications i.e. refuse haulers, transit coaches, etc.  They are suggesting using tandem air dryers, which further need control modules to deliver air fast enough to meet the requirement for continuous uninterrupted air supply.  This not only more than doubles the weight of the dryers as well as maintenance, but critically increases the backpressure required for air dryer operation from 4-20+ psi (for single canisters) to 60-84+ psi (for dual canisters)!  This backpressure severely affects compressor efficiency and promotes wear as well as carbon build-up.  Another effect of back pressures is that it super heats the air and oil vapor which, combined with additives in the oil, results in the formation of acids which are carried in the air stream and later re-condense during cooling.  These acids can be most destructive to air system components.  Carbon build-up and super heating of the air can be curtailed by not having any device in-line which either affects or restricts airflow between the compressor and the wet tank.

As an afterthought one manufacturer has introduced a system filter to specifically handle oil vapor that gets passed the air dryer in which they admit, ". . . increase compressor discharge temperatures allow the oil vapor
Loadcraft (6 axle) Mobile Oil Rig Utilizing ClearDrain
(Before Air Frame is Extended)
to pass through the air dryer and condense downstream in air components.  This condensed oil can cause valves and air powered accessories to stick or even fail, resulting in reduced component life and increase vehicle downtime.”  Additionally, this filter must be changed once a year and the oil manually drained from the filter on a monthly basis!  This system adds yet another 2 1/2 lbs. to an already heavily weighted air dryer system!  Interestingly, the manufacturer notes that the oil filter has a bypass valve that allows supply air to continue through the brake system in the event the filter becomes clogged.  We might ask if the filter becomes clogged or is not manually drained monthly what effect do you suppose all that oil vapor will have on air components further downstream?  Another question is the oil filter not also contributing to further backpressure, carbon build-up and increased compressor wear?  

Interestingly, many dryer manufacturers either offer and/or recommend a spitter or blow-off drain valve to be used in conjunction with the air dryer, what is that telling you about the performance capabilities of the dryer itself?

Finally, yet another product introduced is an air dryer utilized just for trailers!  It is intended to protect trailer valves, ABS, CTS, etc and prevent contaminants and moisture from entering air suspension valves and air bags.  It also has a bypass valve in the event the dryer is obstructed.  This is yet another system attempting to manage the problems created by the primary air dryer not being adequate to meet the need for providing air system protection with just one product.  End result is more weight, more maintenance and more backpressure.

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