Chevrolet 10 Series 1968, Руководство по обслуживанию

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CLUTCHES AND TRANSMISSIONS 7-22
C O N TR O L VALVE
C O N N E C T O R S
BLACK LINE, AIR FLO W
W HITE LINE, C O N S T A N T
AIR TO “ IN " PORT O F
C O N TR O L VALVE
AIR VALVE
SHIFT CYLIN DER
CO VER
HIG H R A N G E
AIR LINE
CO N T R O L BUTTON
(Install at Least 6"
Below Center of Ball Gri|
BREATHER \
C O N S T A N T AIR SUPPLY
C O N T R O L BUTTON UP
HIG H R A N G E, C O N TR O L
VALVE IS C LO SE D A N D N O
AIR PA SSES THROU GH
C O N TR O L BUTTON D O W N
LO W R A N G E, C O N TR O L
VA LV E IS O PEN A N D AIR
PA SSES TH RO U GH TO END
PORT O F AIR VALVE
T-2489
REGU LATOR
57.5 TO 62.5 PSI
FILTER
F ig . 12C—Range Shift System—RT-510 Transmission
valve, there are defective parts or “ O” rings in
the control valve.
2. If there is a steady leak out the breather on the air
valve: There is a defective
“ O”
ring in the air
valve; or there is a leak past
“ O”
rings on the
shift cylinder piston (see Check Point
“ E ” ).
3. If transmission fails to shift into low range or is
slow to make the shift and the transmission case is
pressurized, see Check Point
“ E . ”
4. Tighten loose connections and replace all defective
parts.
Check Point “ A ”
1. If there is a steady leak from exhaust port, this
indicates a ruptured diaphragm, or that dirt and
rust have clogged the regulator piston in the input
port at the seal. Inspect and replace diaphragm if
necessary. Clean regulator.
2. Cut off the vehicle air pressure and install air gauge
into the air system at the output port of the regulator
valve. Bring the vehicle air pressure to normal.
Check the pressure reading which should be 57.5
to 62.5 psi.
3. If gauge reads full line pressure, plus steady leak
in regulator exhaust port, this indicates ruptured
diaphragm or dirty regulator.
4. If gauge registers less than line pressure but above
64 psi, this indicates the V-shaped piston spring is
weak, or that piston seal is defective.
5. Pulsating gauge indicates loose lock ring which at­
taches the two sections of the air regulator.
6 . If, after cleaning regulator and replacing worn parts,
the regulator still does not read within limits, regu­
lated pressure can be changed by the addition and
removal of shims.
a. Add shims to raise air pressure.
b. Remove shims to lower air pressure.
7. One shim is equal to approximately 2 psi pressure
change.
8
. Only as a last resort should an adjustment be made
with the screw in end cap of regulator. This adjust­
ment has been set for correct operating limits. Any
deviation from these limits, especially on regulators
which have been in operation for some time, will in
most cases be caused by dirt or worn parts. Adjust­
ment of screw will give only a temporary remedy.
CHEVROLET TRUCK SERVICE MANUAL