GMC 1976 ZEO 6083 Maintenance Manual page 830

24L- 4
HOLDING TANK AND DRAINAGE SYSTEM
2. Connect two electrical leads to holding tank
gauge sending unit .
3 . Install valve rod on drain valve and secure with
cotter pin.
4. Install dump tube with fullway valve to hold-
ing tank with four screws .
5 . Screw toilet mounting flange into holding tank
and secure with six screws to floor.
6. Install toilet as described in SECTION 24K.
REMOVAL
FULLWAY VALVE
1 . Drain holding tank completely and close full-
way valve .
2. At dump tube assembly remove the four
screws securing valve to the tank . Remove cotter pin
from control rod.
3 . Remove six bolts and nuts from dump tube
bracket near tank .
4. Remove two bolts, washers, and nuts from
clamp that secures dump tube to vehicle at bend in
tube .
5. Unhook strap that supports dump tube at cap.
Remove the fullway valve and the dump tube assem-
bly.
Figure 4-Dump Tube and Valve Assembly
INSTALLATION
1 . At dump tube assembly, apply a film of grease
to valve where "O" ring seats against valve. This will
hold the new "O" ring in position while installing
valve.
2. Position valve at holding tank and assemble
enough to loosely install the strap (figure 4) . Tighten
fullway valve to tank screws .
3 . Position valve with dump tube to tank and
loosely install clamp to support tube .
4. Tighten fullway valve to tank screws .
5 . Install bracket with six bolts and nuts . Torque
to 15 ft. lbs . Tighten clamp bolts. Torque to 15-25 in .
lbs.
6. Install valve rod and secure with cotter pin .
Connect tube support strap.
7. Check tank and valve for leaks.
HOLDING TANK SENDING UNIT
REMOVAL
1 . Disconnect two electrical leads to unit as
shown in Figure 5.
2 . Remove five screws retaining sending unit to
holding tank, and remove sending unit .
Figure 5-Holding Tank Sending Unit