Jaguar XJ (X351) V8-5.0L SC Technical Service Bulletin # JTB00278 Date: 121212
Cooling System - Water Pump Leak
JTB00278NAS1
12-DEC-12
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SECTION: 303-03
Engine Coolant Leak at Coolant Pump
AFFECTED VEHICLE RANGE:
XF (X250) 5.0L V8 Only VIN: R36915-Onwards
Model Year: 2010-Onwards
XJ (X351) VIN: V00047-Onwards
Model Year: 2010-Onwards
XK (X150) VIN: B32753-Onwards
Model Year: 2010-Onwards
CONDITION SUMMARY:
Situation:
The fluid level in the engine coolant system expansion tank may fall below the minimum level over a period of time or a Low coolant level message
is displayed in the message center. Upon inspection, a leak may be found to be from the front of the engine-driven coolant pump together with
excessive wear of the coolant pump bearing.
NOTE:
The coolant pump can display some dry coolant residue on the pump body and surrounding area during normal operation. A small amount of coolant
may temporarily weep through the pump seals or from the evaporation chamber. This does not affect the operation of the pump or the cooling system
and does not damage the coolant pump. A small amount of dry coolant residue on the pump body, pulleys, belts, or around the front of the engine is
not alone sufficient justification for changing a coolant pump.
Cause:
This may be caused by coolant ingress into the coolant pump bearing housing, leading to corrosion of the bearing and incorrect support for the
impeller shaft, leading to accelerated wear of the mechanical flat-face of the seal and a coolant loss sufficient to display the warning message.
Action:
In the event of a customer concern of the above, refer to the Repair Procedure outlined below.
PARTS:
No parts necessary
TOOLS:
Refer to Workshop Manual for any required special tools
WARRANTY
Normal Warranty policies and procedures apply
REPAIR PROCEDURE
NOTE:
The coolant pump can display some dry coolant residue on the pump body and surrounding area during normal operation. A small amount
of coolant may temporarily weep through the pump seals or from the evaporation chamber. This does not affect the operation of the pump
or the cooling system and does not damage the coolant pump. A small amount of dry coolant residue on the pump body, pulleys, belts, or
around the front of the engine is not alone sufficient justification for changing a coolant pump.
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1. NOTE: Acceptable Coolant Pump Witness Marks
Check the coolant pump for witness marks before continuing.
^ Note the severity of any witness marks on the repair order.
2. Check the expansion tank level and message center for a low coolant warning; record on the repair order.
^ If there is low coolant in the expansion tank and or a low coolant message from the message center, continue to next step.
^ If a leak is located this must be claimed as a separate claim.
3. Top up the coolant to the correct level.
4. NOTE: A 1.0-1.5 PSI pressure drop is normal, and does not indicate a system leak. An air leak may also be present in the pressure test
equipment.
Carry out a cooling system pressure test to 1 bar (15 PSI) pressure test the system for 5 minutes.
^ Record the pressure drop (if any) on the repair order.
^ If there is a cooling system pressure drop of more than 1.5 PSI, then investigate the system for fresh wet leaks and record on a repair order.
A UV light may be helpful as there is a UV dye in the coolant.
^ If there is fresh wet coolant dripping from the pump - this indicates a leak. Coolant residue is normal and does not indicate a leak.
5. If no leak is found starting the engine from cold, listen for unusual noise (moaning, groaning, rumbling, grinding); record results on the repair
order.
6. Stop the engine; slacken the FEAD belt tensioner and slip the FEAD belt to one side.
7. Hold the coolant pump pulley firmly and rock it up and down by hand.
^ Feel for excessive play.
^ Rotate the pulley 1/4 turn and repeat the rocking motion a few times.
^ Record results on the repair order.
8. Spin the pulley and feel for roughness.
^ Record results on the repair order.
9. If there is excessive play in the pulley bearing, refer to Workshop Manual section 303-03 and replace the coolant pump; to be carried out as a