Draining Cooling System - PREVOST H3-41 Maintenance Manual

Typical material required:
•
Hand Vacuum Pump w/ bottle provision
•
Sample bottle
•
Plastic tube (1/4 "refrigerator" tube)
•
Nitrile gloves
•
Security glasses
•
Shop Towels
NOTE
Watch out for accidental contamination!
Hand vacuum pump should be used for
coolant sampling only to prevent cross-
contamination.
Also, ensure cleanliness
procedure to make sure the coolant sample is
not contaminated accidentally.
Sampling should be performed on the surge
tank, on a cold engine.
If the vehicle has been standing still for a
significant period, drive it around 30 min up to
normal operating temperature. Then let it cool
down.
1. Pull the pressure cap off the surge tank.
Refer to Figure 1 for location of cap.
2. Thread the sample bottle to the pump. Hand
tighten.
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.
throughout this
PA1615 Maintenance Manual All Series
SECTION 05b: X3 SERIES COOLING SYSTEM
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 shutoff valves.
On X3- 45 coaches & VIP, and also on XLII
Entertainer Bus Shells, the valves are located in
the engine compartment. One is located under
the radiator fan drive mechanism support;
another valve is on the L.H. side of the engine
compartment in front of the radiator (Figure 6).
NOTE
Refer to section
System" for information about preheater
access and heater line shutoff valve.
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).
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.
|
Section 05b revised September 2016
required by the
22 under "Preheating
Coolant Additives
15