AIR SYSTEM COMPONENTS
SUB-SECTION 9C
seat and the exhaust is closed. Air pressure then has free
LEAKAGE TEST. To determine if the valve is leaking inter.
passage through the valve to the upper throttle reservoir.
nally, perform the following test:
The inlet valve of the lower delivery port is seated when the
1. Fully charge the air system.
handle is in the UPPER position. This prevents air from
passing through the valve and allows any air pressure which
2. Place the control lever in the LOCK position. Coat the
is trapped in the air line to the lower throttle reservoir to
exhaust port of the valve with a soap solution to check for
escape through the valve.
leakage.
The selector valve operates in exactly the same manner
3. Place the control lever in the UNLOCK position. Then
when the handle is in the LOWER position, except that the
coat the exhaust port with a soap solution to check for
air is directed to the lower throttle reservoir.
leakage.
LEAKAGE TEST. To determine if the valve is leaking inter-
4. If the valve does not function as described, or leaks ex-
nally, perform the following test:
cessively, it is recommended that the valve be replaced.
1. Fully charge the air system.
REMOVAL. To remove the differential lockout valve, pro-
ceed as follows:
2. Place the handle in the UPPER position. Then coat the
area around the handle with a soap solution to check for
1. Drain the air system by opening the drain cock on each
leakage.
reservoir.
3. Place the handle in the LOWER position. Again, coat the
2. Disconnect the air lines at the valve.
area around the handle with a soap solution to check for
leakage.
3. Remove the two screws on the valve dial, and remove
the valve dial. The valve can now be removed from the dash
4. If leakage is excessive, it is recommended that the valve
panel.
be replaced.
INSTALLATION. To install a new differential lockout
valve, proceed as follows:
1. Place the valve on the underside of the dash panel with
the screw holes properly aligned with the holes in the dash
panel.
2. Place the valve dial on the topside of the dash panel,
over the valve. Then install the screws to secure the valve
and dial to the dash panel.
3. Reconnect the air lines to the valve.
4. Check the operation of the valve by performing the
Leakage Test.
THROTTLE SELECTOR VALVE (36Z971)
DESCRIPTION. Throttle selector valve 36Z971 is a lever
operated, three way air control valve (see Figure 9C-12).
The valve is used to direct air from the air system to either
NOTE: HALF OF VALVE SHOWN.
the upper or lower throttle reservoir.
OTHER HALF IDENTICAL
TO HALF SHOWN.
When the handle of the valve is in the UPPER position, the
upper delivery port is on and the lower delivery port is off.
Figure 9C-12. Throttle Selector Valve (36Z971)
In this position, the upper delivery port inlet valve is off its
9C-13
