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4. Run engine 6 to 12 hours and drain system while
warm. Rinse system three times after it has cooled
down. Refill system with water.
CAUTION
Use only ethylene glycol, anti-freeze (with
inhibitors) in system. Use of glycol by itself
will damage the cooling syst em ( Refer to
paragraph 1.10.j.).
5. Run engine to operating temperature. Drain system
again and fill with treated water/anti-freeze (see
above Caution note).
4.4.6 Servicing the Low Coolant Sensor
a. Testing the Low Coolant Sensor (LCS)
1. Verify the coolant level is correct.
2. Verify the wiring to the sensor is correct.
3. Check voltage (12.5 to 13.5 VDC) to the B terminal
with the ignition switch on (see Figure 4-2).
4. Check continuity between terminals A and C (see
Figure 4-2) while 12 VDC is applied to terminal B.
5. Drain the coolant from the system to below the level
of the coolant sensor and remove the sensor as
described in Section 4.4.6.b., steps 1 and 2 below .
6. With the sensor removed from the radiator and 12
VDC applied to terminal B, the circuit between
terminals A and C should be open.
Figure 4-2 Low Coolant Sensor
CAUTION
Never open the radiator cap when the
coolant is hot.
b. Replacing the Low Coolant Sensor (LCS)
1. Loosen the radiator drain pet cock and drain coolant
to a point below the sensor into an approved
container.
2. Unplug the harness and remove sensor from
radiator header.
3. Apply Teflon thread tape or thread sealer to the LCS
threads and install sensor.
4. Reconnect the harness and refill the radiator to
proper level.
4.4.7 Servicing Low Oil Pressure Switch
1. Remove harness connection from low oil pressure
switch (LOP).
2. Remove pressure switch from engine.
3. Apply Tef lon thread sealer to threads of new low oil
pressure switch.
4. Install new low oil pressure switch.
5. Reconnect harness connection to low oil pressure
switch.
4.4.8 Servicing Heater Switch
1. Remove control box cover.
2. Remove all c onnections going toheater switch (HS).
3. Remove heater switch from control box.
4. Install new heater switch.
5. Reconnect wire harness connections to switch.
6. Confirm that wires are connected to correct
terminals.
7. Reinstall control box cover.
4.4.9 Servicing Poly V-belt
WARNING
Beware of moving poly V-belt and belt
driven components.
WARNING
Beware of pinch points.
NOTE
A frayed, cracked or worn poly V-belt must be
replaced. After i nstalling a new belt, check the
adjustment after running the unit for three or
four hours. This will allow for the initial stretch,
which is common on new belts. Once this initial
stretch has taken place, the belt should be
checked at regular intervals.
The poly V -belt is driven by a sheave on the engine
crankshaft. Its two functions are: (1) to drive theradiator
fan and (2) to drive the water pump.
To replace the poly V-belt, perform the following steps:
1. Using the proper size socket, s lowly r otate the crank
on the crank pulley nut. At the same time, use a flat,
blunt object to guide the belt off the crank pulley
towards radiator. Be careful not to damage grooves
on the pulley.
2. Replace the poly V-Belt by positioning the belt onthe
water pump pulley, and while rotating the engine (as
in step 1), use a flat, blunt object to guide the belt
onto the crank pulley. Be careful not to damage
grooves on the pulley or belt.
