Thermostat Operation; Thermostat Replacement; Checking New Thermostat - PREVOST H3-41 Maintenance Manual

FIGURE 12: CHARGE AIR COOLER HOSE CLAMPS
CAUTION
The hose clamps will break if over-tighten. Do
not over-tighten, especially
weather when hose has contracted.
Maintenance
Since the constant-torque clamp automatically
adjusts to keep a consistent sealing pressure,
there is no need to re-torque hose clamps on a
regular basis. During vehicle operation and
shutdown, the screw tip will adjust according to
the temperature and pressure changes.
Checking for proper torque should be done
at room temperature.
5

THERMOSTAT OPERATION

5.1

THERMOSTAT REPLACEMENT

1. Drain the cooling system.
2. Remove the bolts, the thermostat housing
and the thermostat. Carefully clean the
thermostat seat and all cylinder head-to-
thermostat housing mating surfaces.
SECTION 05A: H3 SERIES COOLING SYSTEM
FIGURE 13: VOLVO D13 THERMOSTAT HOUSING
3. Install the new thermostat. Make sure that
4. Position the thermostat housing to the
5. Install the rubber radiator hose to the
during cold
6. Fill the system with the recommended
7. Start the engine, check for leaks and proper
5.2
A function check must be carried out before
installing a new thermostat.
1. Warm up water in a receptacle to 75°C
2. After at least 30 seconds, check that the
PA1621 Maintenance Manual All Series | January 2017
the rubber seal remains properly seated.
cylinder head, install and tighten the bolts.
TORQUE: 15-21 lb-ft (20-28 Nm)
thermostat housing. Position the clamp and
tighten to secure.
coolant.
operation. After shutdown, replenish fluids as
necessary.

CHECKING NEW THERMOSTAT

NOTE
Check to be sure if the new thermostat closes
fully. This can be done by holding it up to the
light to check that there is no visible gap at the
opening point. If the thermostat does not close
properly, replace it.
(167°F) and immerse the thermostat in the
water. Use a piece of wire attached to the
thermostat.
thermostat is still closed.
13