Wrangler 4WD L4-150 2.5L VIN P MFI (1998)
Water Pump: Description and Operation
GENERAL INFORMATION
A centrifugal water pump circulates coolant through the water jackets, passages, intake manifold, radiator core, cooling system hoses and heater
core. The pump is driven from the engine crankshaft by a drive belt. A gasket is used as a seal between the water pump and timing chain
case/cover.
IMPELLER
The water pump impeller is pressed onto the rear of a shaft that rotates in a bearing pressed into the water pump body. The body has a small hole
for ventilation.
SEALS
The water pump seals are lubricated by antifreeze in the coolant mixture. Additional lubrication is not necessary.
FUNCTION CHECK
A quick test to determine if pump is working is to check if heater warms properly. A defective water pump will not be able to circulate heated
coolant through the long heater hose to the heater core.
NOTE: The water pump on all models can be removed without discharging the air conditioning system (if equipped).
CAUTION: This engine is equipped with a reverse (counter-clockwise) rotating water pump. The letter R is stamped into the back of the water pump
impeller.
NOTE: Engines from previous model years, depending upon application, may have been equipped with a forward (clockwise) rotating water pump.
Installation of the wrong water pump will cause engine overheating.