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Maintenance
LTN 6L-V
5.15
Testing the Cooling System Pressure
When
Test the cooling system pressure every 1200 hours, or 24 months (whichever
comes first).
Background
The cooling system is under pressure while the engine is operating. Internal or
external leaks will cause the cooling system to lose pressure. These leaks can be
detected by forcing pressurized air into the radiator cap and cooling system while
the engine is stopped.
Requirements
Engine is stopped and cool to the touch
Pressure test kit
Cooling system filled (see
Checking the Engine Coolant Level)
Procedure
Perform the following procedure to test the cooling system pressure.
1. Slowly rotate the radiator cap
(a)
counterclockwise to release any remaining
system pressure. Unscrew and remove the radiator cap after the pressure has
been released.
2. Note the rated operating pressure marked on the outside of the radiator cap.
When this pressure level is reached, a relief valve in the cap discharges coolant
into the overflow bottle.
This procedure continues on the next page.
WARNING
Burn hazard. Engine coolant is hot and under pressure at operating temperature.
f
Test the cooling system pressure only when the engine is stopped and the radi-
ator is cool to the touch.
WARNING
Burn hazard. Engine coolant may contain alkali.
f
Avoid coolant contact with skin and eyes.
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