Thermo King T-1080S, Maintenance Manual

Page: 92 / 191

Engine Maintenance
91
2. Open the bleed valve on the thermostat
housing (see Figure 165).
3. Fill the cooling system via the expansion tank
until the coolant level is approximately 5
inches below the top of the tank cap opening,
see Figure 166. (When the vacuum is applied
the coolant hoses will collapse under vacuum
and the coolant level in the tank will rise. If
the level in the tank is too high before the
vacuum is applied, coolant will be draw into
the vacuum pump).
4. Close the bleed valve on the thermostat
housing (see Figure 165).
5. Install a vacuum fill system and pull the
cooling system down to a full vacuum. (An air
driven venturi vacuum system will achieve
approximately 27 inches of mercury [hg]
vacuum while a vane or piston vacuum pump
will achieve 29 inches of mercury vacuum.
For the fill operation the deeper vacuum is
better.) If the vacuum is unsteady or sputtering
continue to apply the vacuum until it becomes
steady and then hold it for an additional 60
seconds.
6. Isolate the cooling system from the vacuum
pump with a shut off valve and check for
vacuum decay (an indication of cooling
system leak). Fix any leaks or connections
before filling the system.
7. Fully prime the coolant fill hose tube with
coolant and connect to the vacuum fitting on
the cooling system. Failure to remove all the
air from the coolant fill hose will introduce air
into the system and result in a system that is
low on coolant.
8. Slowly open the valve and admit fresh coolant
to the cooling system.
9. When the system is full, remove the cap and
top off coolant to the expansion tank opening
to ensure the tank is full to the level of the
overflow inlet passage in the filler opening,
(see Figure 167).
1. Bleed Valve
Figure 165: Open Bleed Valve
1. 5 Inches
Figure 166: Fill Cooling System Via Expansion Tank
1
1
1. Fill to Here
Figure 167: Top Off Expansion Tank
1