TM 5-3805-263-14&P-3
QUICK RELEASE VALV
SYSTEMS OPERATION
The quick release valve is connected to the inlet port
of the rotochamber for the parking brake. The line from
the delivery port of the control valve for the parking brake
is connected to inlet port (4) on the quick release valve.
The quick release valve is used to shorten the time
needed to release the parking brake. It is used to let the
air out of the brake chamber sooner. Air is released
through the exhaust port (7) in the quick release valve so
it does not have to go back to the control valve for the
parking brake to get out.
Operation
The quick release valve has three normal positions
during operation.
These positions are the
APPLICATION position (when air under pressure goes
QUICK RELEASE VALVE IN HOLD POSITION
through the valve into the brake chamber), the HOLD
As soon as brake chamber pressure below the
position (when pressure is kept in the brake chamber)
diaphragm is equal to brake valve pressure above the
and the EXHAUST position (when air in brake chamber
diaphragm, the edge of the diaphragm (5) moves up
is being let out).
against the body. The center of the diaphragm continues
to cover exhaust port (7). This is the HOLDING position.
QUICK RELEASE VALVE IN EXHAUST POSITION
When brake control valve is CLOSED, line pressure on
QUICK RELEASE VALVE IN APPLIED POSITION
top of diaphragm is released. The brake chamber
1. Outlet port to brake chamber. 2. O-ring seal. 3.
pressure below center of the diaphragm raises it,
Cover. 4. Inlet port. 5. Diaphragm. 6. Body. 7.
opening exhaust port (7) and permitting brake chamber
Exhaust port. 8. Plug.
air to be released to atmosphere.'
When the brake control valve is opened, air under
The diaphragm again assumes HOLDING position as
pressure enters inlet port (4) of quick release valve and
soon as pressure above and below it is equalized
moves diaphragm (5) down, to close exhaust port (7).
The outer edges of the diaphragm are deflected
Use a nonflammable cleaning solvent to clean any
downward allowing air under pressure to pass through
accumulations of grease and dirt from the area of the
outlet port (1) to brake chamber, applying the brake.
quick release valve.
One quick release valve is shown. On the left valve, plug
(8) is in opposite brake port.
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