Chevrolet 30 Series 1967 Service Manual page 209

seconds, release the accelerator, and turn off the ignition
switch. Immediately measure the distance between the
face of the locking cylinder mounting bracket and the
center of the push rod yoke to the lever pin and make
note of the dimension. At the end of ten minutes, re­
measure the distance. If the distance has not increased,
the system may be considered vacuum tight. However, if
the distance has increased, a vacuum leak exists in the
system.
F irst check all connections. After all the hoses and
the pipe connections have been checked and tightened, test
the system again.
SOLENOID LOCK VALVE
The solenoid valve is positioned at the frame left side
rail by the vacuum pipe clips and may be removed by dis­
connecting the three fittings at the valve.
LOCKING CYLINDER
When leakage tests indicate the locking cylinder as­
sembly leaks, it must be removed and disassembled, and
the rubber diaphragm in the cylinder must be replaced.
1. Disconnect the control valve hose from the cylinder.
Remove the cotter pin and the clevis pin which se­
cure the bracket lever to the push rod. Remove the
snap ring which secures the cylinder in the bracket,
and remove the assembly from the bracket. Remove
Fig . 9 4 - Differential Lock Vacuum System (Typ ical)
REAR SUSPENSION AND DRIVE LINE 4-51
1. D ifferential C arrier Cover
2. Bracket
3. Push Rod Yoke
4. Boot
5. Lock N ut
6. Push Rod
7. Snap Ring
8. Dowel
9. C y lin d e r (Inner H alf)
10. Diaphragm
11. C ylin d er (O uter H alf)
12. Vacuum Line Fitting
13. N ut
14. Plate Washer
15. Plate (Large)
16. Plate (Sm all)
17. Lock-Out Shift
Lever
CHEVROLET TRUCK SERVICE MANUAL