Bendix Commercial Vehicle Systems DV-2 AUTO RESERVOIR DRAIN VLV 10/11 - Manual (Page 2)

2
FIGURE 3 FIGURE 4
FIGURE 1 FIGURE 2
NOTE: If a vehicle equipped with a Bendix ® DV-2 ™ automatic drain
valve(s) is operated in subfreezing temperatures, it is
recommended that a heated reservoir drain valve is installed.
OPERATION
Referring to Figure 1, with no air pressure in the system, the inlet and
exhaust valves are closed. Upon charging the system, a slight pressure
opens the inlet valve (Figure 2) which permits air and contaminants to
collect in the sump. The inlet valve remains open when pressure is
ascending in the system until maximum (governor cutout) pressure
is reached. The spring action of the valve guide in the sump cavity
closes the inlet valve. The inlet valve and the exhaust valve are now
closed (Figure 3).
When reservoir pressure drops slightly (approximately 2 psi), air
pressure in the sump cavity opens the exhaust valve (Figure 4) and
allows moisture and contaminants to be ejected from the sump cavity
until pressure in the sump cavity drops suffi ciently to close the exhaust
valve.
The length of time the exhaust valve remains open and the amount of
moisture and contaminants ejected depends upon the sump pressure
and the reservoir pressure drop that occurs each time air is used from
the system.
Manual draining can be accomplished as follows:
Using a tool, move the wire in the exhaust port upward, holding it in
until draining is completed.
The thermostat on the heated model DV-2 ™ automatic drain valve will
activate the heating element when the valve body reaches a temperature
of approximately 45°F and will deactivate the heating element when
the valve body is warmed to approximately 85°F.
PREVENTIVE MAINTENANCE
Important:
Review the Bendix Warranty Policy before performing any
intrusive maintenance procedures. A warranty may be voided if intrusive
maintenance is performed during the warranty period.
No two vehicles operate under identical conditions, as a result,
maintenance intervals may vary. Experience is a valuable guide
in determining the best maintenance interval for air brake system
components. At a minimum, the automatic reservoir drain valve should
be inspected every 6 months or 1500 operating hours, whichever comes
fi rst, for proper operation. Should the automatic reservoir drain valve
not meet the elements of the operational tests noted in this document,
further investigation and service of the valve may be required.
Upon investigation, parts showing signs of wear or deterioration should
be replaced.
If there is a fi lter screen in the adapter fi tting it should be removed and
discarded.