Thomas SAF-T-LINER C2, Maintenance Manual

Page: 56 / 176

20–06 Coolant Change, Electric
Vehicle
WARNING
Do not remove or loosen the radiator cap until the
motor and cooling system have completely
cooled. Use extreme care when removing the cap.
A sudden release of pressure from removing the
cap prior to the system cooling can result in a
surge of scalding coolant that could cause seri-
ous personal injury.
1. Remove the fill caps from the powertrain/battery
loop and dash/body heater surge tanks. See
Fig. 1 .
2. Place a large container under the radiator.
3. Remove the drain plug at the bottom of the ra-
diator. See
Fig. 2 .
4. Remove the drain plug for the heater manifold,
shown in
Fig. 3 , to help drain the heater circuit.
NOTE: Additional hoses at other locations can
be removed and shop air applied to help drain
the coolant; draining coolant from the batteries
is also recommended.
5. Install the drain plug in the line to the heater
manifold.
6. Install the drain plug in the radiator.
7. Install any coolant lines that were removed to
drain the coolant.
NOTICE
Distilled water must always be used when mixing
a 50/50 mixture of coolant concentrate and water.
Normal tap water will lead to corrosion of the
powertrain and battery coolant loops. This type of
damage is not covered by warranty.
If a pre-mixed coolant/water solution is used, dis-
tilled water does not need to be added.
IMPORTANT: The powertrain/battery loop surge
tank must be filled
first . Ensure that the dash
controls are set to cold and the blower is off.
Supplemental coolant additives (SCAs) are not
used with OAT coolant.
8. With the dash controls set to cold and the blower
off, fill the powertrain/battery loop surge tank to
the COLD FULL mark on the tank with organic
acid technology (OAT) coolant; approximately 47
quarts (44 L) of coolant.
9. Start the vehicle and add coolant until the surge
tank is at the full mark.
10. Drive the vehicle 15 to 20 miles (24 to 32 km) to
expel trapped air. Check the coolant level in the
surge tank and add coolant if needed.
11. After driving the vehicle 50 miles (80 km), check
the coolant level again and add coolant to the
HOT FULL mark if needed.
IMPORTANT: Fill the dash/body heater surge
tank
after the powertrain/battery loop surge
tank. Starting the vehicle automatically turns on
the pumps for the powertrain/battery loop; these
pumps must not be ran without the proper
amount of coolant in the system. The dash/body
heater pump activates when the dash control is
set to hot and the blower is running.
f200955 02/23/2021
1
2
3
1. Powertrain/Battery Loop Surge Tank
2. Dash/Body Heater Surge Tank
3. Sight Glass
Fig. 1, Surge Tanks
Engine Cooling/Radiator
20
Saf-T-Liner C2 School Bus Maintenance Manual, May 2021
20/4