2
Inspection and adjustment
COOLING SYSTEM XF ENGINE
4-3
4.3 CHECKING THE VISCOUS FAN CLUTCH
Do not run the engine in an
enclosed or unventilated area.
Make sure exhaust fumes are
properly extracted.
Maintain a safe distance from
rotating and/or moving
components.
Testing with a cold engine
During this test, the slip in the viscous fan clutch
is measured, when the clutch is not operational.
This test must be carried out with a “cold”
engine (coolant temperature
approximately 50
_C).
1.
Check the coolant level, and as necessary
top up with coolant.
2.
Start the engine and run it at idling speed
for at least 5 minutes.
3.
Then use a digital revolution counter to
measure the fan speed at a number of
engine speeds (from idling to maximum
engine speed).
During this test procedure, the speed of the
fan should be approx. 600 to 1100 rpm.
Testing with a warm engine
This test checks whether the contact operates at
an operating temperature of 85 - 95
_C.
1.
Check the coolant level, and as necessary
top up with coolant. Be careful when
topping up the coolant, if the engine is
warm.
2.
Remove the front engine encapsulation.
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