TRUCK SERVICE MANUAL
1. Block and hold vehicle by means other than air
2. Remove cover and sealing ring.
2. Drain air system.
NOTE: If the heater or thermostat has failed, the
entire cover must be replaced. Do not remove the
3. To prevent early plugging of the filter, thoroughly
thermostat cover plate. It is moisture sealed and
flush and clean reservoir before installing drain
removal could result in early thermostat failure.
3. Remove valve guide.
4. Aerate any tank thoroughly if any solvents have
been used in the cleaning process.
NOTE: When installing the automatic reservoir
5. Remove adapter and filter assembly.
drain valve equipped with a heater and thermostat,
first determine if the vehicle electrical system is
6. Remove filter retainer.
12volt or 24volt and that the heater/thermostat unit
is of the same voltage. The #14 gauge lead wire on
7. Remove filter.
the valve should be connected to the "on" position
of the engine control or ignition switch. Use an
CLEANING AND INSPECTION
8amp fuse for one valve, a 15amp fuse for two
1. Cleaning solvent may be used on metal parts.
valves and a 20amp fuse for three valves. All
2. Rubber parts should be wiped clean.
electrical connections must be waterproof.
4. Clean and inspect filter and replace if clogged.
Refer to Fig.
13 for disassembly of valve and
proceed as follows:
Fig. 13 Sectional View of Automatic Reservoir Drain Value