MTZ 1220.1, Operator'S Manual

Page: 46 / 244

MTZ 1220.1/1220.3 Section D . Operation controls and instruments
D26
Cab heater fan control
To turn on the heater conditioner,
proceed as follows:
1. After refilling the cooling system
with antifreeze agent, start the engine
and let the engine work at medium
speed to have the antifreeze agent in
the cooling system warmed up to 50 to
60°
С , after that open the heater valve
by turning lever 1 of the heater coun-
terclockwise up to the stop. If a heater
valve is installed outside a cab, turn a
lever 1
а . Then increase the engine
speed and let it work for 1 to 2 mi-
nutes, slightly open a plug 5 of a drain
valve cock on the right side to ensure
that cooling agent circulates through a
heat exchanger. The heat exchanger
must start warming up. The coolant
level in the diesel heat exchanger of
the engine cooling system will drop at
that
2. Add coolant to the diesel heat ex-
changer to the required level (50…60
mm below top edge of filler neck).
3. Engage heater fan with switch 3
and direct the air flow via air distribu-
tors 4.
4. with the recirculation shutters 2,
the quantity of fresh air delivered into
the cab can be adjusted.
5. To drain the coolant from the heat-
ing system there is drain plug 5 on the
left and right sides of a cab. After the
coolant is drained, it is necessary to
blow the system off with compressed air
after closing a valve cylinder block and
turning off plugs 5. Tighten the plugs
after blowing off.
ATTENTION: heater control valve
shall be closed for system operation in
ventilation mode during a warm sea-
son.