Draining Cooling System - PREVOST H3-41 Maintenance Manual

SECTION 05A: H3 SERIES COOLING SYSTEM
2. Thread the sample bottle to the pump. Hand
tightens.
3. Slide the plastic tubing in the fitting on the
pump until it exceeds about 1/2 inch into
pump cavity.
4. Insert tube in the surge tank about half way
to the bottom. (Do not draw sample in the
bottom of the surge tank.)
5. Pump until sample bottle is about 2/3 full. Do
not overfill.
6. Loosen pump fitting to remove tube from
pump. Allow any coolant in the tube to flow in
the bottle.
7. Remove sample bottle and install cap.
8. Throw plastic tube away. (Not to be re-used)
9. Complete any forms
laboratory.
7

DRAINING COOLING SYSTEM

Use the following procedures to drain the
cooling system partially or completely.
To drain engine and related components:
1. Stop engine and allow engine to cool. Close
both heater line shut-off valves.
One valve is located in the engine compartment
near the water pump (Figure 15). Another valve
is located behind rear fender, above the L.H.
rear wheelhousing near the optional coolant
heater.
NOTE
Refer to section
System" for information about preheater
access and heater line shutoff valve.
16 PA1621 Maintenance Manual All Series | January 2017
required by the
22 under "Preheating
MAINTENANCE
Cooling system
Drain, flush, thoroughly clean and refill the
system at the intervals specified by the
Lubrication And Servicing Schedule in Section
24: LUBRICATION & SERVICING.
When using ELC, do not use a filter that
contains Supplemental
(SCA).
FIGURE 15: HEATER LINE SHUTOFF VALVES
WARNING
Before proceeding with the following steps,
make sure the coolant has cooled down. The
sudden release of pressure from a heated
cooling system can result in loss of coolant
and possible personal injury (scalding) from
the hot liquid.
2. Close the shut-off valve on the coolant filter
mounting head and remove filter (perform
only if filter as to be replaced).
3. Open the shut-off valve on the coolant filter
mounting head and drain the coolant into a
suitable container. Close the shut-off valve.
4. Unscrew the surge tank pressure cap
counterclockwise, ¼ turn to let air enter the
system and permit the coolant to drain
completely from system.
Coolant Additives