Operation and maintenance manual

QSB4.5 and QSB6.7 Cooling System
Section 5 - Maintenance Procedures at 500 Hours or 6 Months Page 5-1
Maintenance Procedures - Overview
General Information
All maintenance checks and inspections listed in previous
maintenance intervals must also be performed at this
time, in addition to those listed under this maintenance
interval.
Cooling System
General Information
WARNING
Do not remove the pressure cap from a hot engine.
Wait until the coolant temperature is below 50°C
[120°F] before removing the pressure cap. Heated
coolant spray or steam can cause personal injury.
NOTE: Never use a sealing additive to stop leaks in the
coolant system. This can result in coolant system plugging
and inadequate coolant flow, causing the engine to
overheat.
The engine coolant level must be checked daily.
CAUTION
Do not add cold coolant to a hot engine. Engine
castings can be damaged. Allow the engine to cool
below 50°C [120°F] before adding coolant.
On applications that use a coolant recovery system, check
to make sure the coolant is at the appropriate level in the
coolant recovery tank for the engine temperature.
Many coolant recovery/expansion tanks, also called "top
tanks", have sight glasses (1) or are made of a clear
material (not shown) to aid in checking the coolant level
(2) without removing the radiator cap.
It is important to understand the impact of temperature on
the expansion of the coolant. Most "top tanks" do not
have a provision for a "FULL HOT" coolant level. Filling
the "top tank" while hot will result in a low operating level
once the system has cooled.