
1) Drain cooling system. Remove fan shroud and drive belts.
Remove fan assembly.
2) Disconnect heater hoses and lower radiator hose at water
pump. Remove water pump retaining bolts. Remove water pump.
Installation
Clean all gasket surfaces. Install water pump. Tighten bolts
to specification. Ensure pump turns freely. Reverse removal
procedures. Fill and purge air from cooling system.
NOTE: It may be necessary to remove heater hose to remove trapped
air if system cannot be purged using following procedures.
Cooling System Air Purge (Vehicles With Coolant Recovery)
Fill system to proper level. Place heater control to "HEAT"
position and temperature control to "WARM" or "HIGH" position. Install
coolant caps. Operate engine to normal operating temperature. Shut off
engine and allow system to cool. Add coolant to recovery bottle.
Repeat procedure to obtain correct coolant level.
Cooling System Air Purge (Vehicles Without Coolant Recovery)
Fill system to proper level. Place heater control to "HEAT"
position and temperature control to "WARM" or "HIGH" position. Operate
engine to normal operating temperature with radiator cap removed. Add
necessary coolant and install radiator cap.
NOTE: For further information on cooling system capacities and
other cooling system components, see ENGINE COOLING SYSTEMS
article.
ENGINE OILING
CRANKCASE CAPACITY
Crankcase capacity is 4 qts. (3.8 L) with oil filter change.
NORMAL OIL PRESSURE
Normal oil pressure should be 13 psi (.91 kg/cm) at 600 RPM
or 37-75 psi (2.6-5.3 kg/cm) at 1600 RPM.
OIL PRESSURE REGULATOR VALVE
Oil pressure regulator valve is located in oil pump body and
is nonadjustable.
OILING SYSTEM
Engine lubrication is provided by the distributor driven
gear-type oil pump. Oil is supplied through the full-flow oil filter
and into an internal oil passage. Internal passage runs along right
side of block and intersects lifter bores.
Oil is then routed to camshaft and crankshaft bearings. Oil
is supplied to rocker arms from the hydraulic lifters and through the
push rods. By-pass valves are located in oil filter mounting and oil
pump.
OIL PUMP
Removal
Remove oil pan. See OIL PAN REMOVAL article. Remove oil pump

Removal
Drain cooling system. Disconnect radiator and heater hoses
from pump. Remove drive belt(s). Remove fan shroud. Remove fan
assembly. Remove electric cooling fan (if equipped). Remove power
steering bracket from water pump. Remove water pump and gasket.
Installation
Ensure gasket surfaces are clean. Install water pump. Tighten
bolts to specification. Ensure pump turns freely. Reverse removal
procedures. Fill and purge air from cooling system.
NOTE: It may be necessary to remove heater hose to remove trapped
air if system cannot be purged using following procedures.
Cooling System Air Purge (Vehicles W/Coolant Recovery)
Fill system to proper level. Place heater control to "HEAT"
position and temperature control to "WARM" or "HIGH" position. Install
coolant caps. Operate engine to normal operating temperature. Shut off
engine and allow system to cool. Add coolant to recovery bottle.
Repeat procedure to obtain correct coolant level.
Cooling System Air Purge (Vehicles W/O Coolant Recovery)
Fill system to proper level. Place heater control to "HEAT"
position and temperature control to "WARM" or "HIGH" position. Operate
engine to normal operating temperature with radiator cap removed. Add
necessary coolant and install radiator cap.
NOTE: For further information on cooling systems, see appropriate
article in the ENGINE COOLING section.
LUBRICATION
CRANKCASE CAPACITY
Crankcase capacity for 4.0L is 5 1/2 qts. (5.2L) or 5 qts.
(4.7L) for 4.2L with oil filter change.
NORMAL OIL PRESSURE
Normal oil pressure should be 37-75 psi (2.6-5.3 kg/cm)
maximum above 1600 RPM. Minimum oil pressure should be 13 psi (.9
kg/cm
) at 600 RPM.
OIL PRESSURE REGULATOR VALVE
Oil pressure regulator valve is located in pump body. Valve
is nonadjustable and serviced as an assembly.
ENGINE OILING SYSTEM
Engine lubrication is provided by the distributor driven
gear-type oil pump. Oil is supplied through the full-flow oil filter
and into an internal oil passage. Internal passage provides oil to the
lifter bores. Oil is then routed to camshaft and crankshaft bearings.
Oil is supplied to rocker arms from the hydraulic lifters and through
the push rods.
OIL PUMP
Removal
Remove oil pan. See OIL PAN REMOVAL in this section. Remove

of the scale, a symbol for defroster indicates defrost position. In
"BI-LEVEL" position, a mixture of floor heat and defroster air is
obtained.
The lower temperature control lever operates blend-air door
in heater core housing. At full right position, all air is directed
through heater core, providing maximum heat flow. At full left
position, all air is directed around heater core providing fresh air.
Control can be set in any intermediate position to provide a blend of
heated and unheated air. Heater must be in heat or defrost mode before
any air can enter vehicle.
TROUBLE SHOOTING
See JEEP TROUBLE SHOOTING at the end of this article.
REMOVAL & INSTALLATION
CONDENSER
Removal (Cherokee, Comanche & Wagoneer) NOTE: On these
models, condenser and receiver-drier are replaced
as a unit.
1) Drain radiator. Disconnect fan shroud and radiator hoses.
Disconnect automatic transmission cooler lines (if equipped).
Discharge A/C system using approved refrigerant recovery/recycling
equipment.
2) Disconnect A/C hoses from condenser. Unplug low pressure
switch. Remove radiator and condenser as an assembly. Detach condenser
retaining bolts. Separate condenser from radiator. Remove receiver-
drier from condenser.
NOTE: Plug receiver-drier openings whenever unit is removed from
condenser. Add 1 oz. of refrigerant oil (AMC No. 8132400) to
system when replacing condenser.
Installation
To install, reverse removal procedure. Fill radiator.
Evacuate, leak test, recharge and check A/C system operation.
Removal (Wrangler)
1) Discharge system (slowly to prevent loss of compressor
oil) using approved refrigerant recovery/recycling equipment. Drain
coolant. Remove fan shroud and radiator. Disconnect pressure line at
condenser. Remove condenser mounting screws. Tilt bottom of condenser
toward engine.
2) From underside of vehicle, disconnect hose attaching
receiver-drier to evaporator. Plug all openings to prevent entry of
dirt or moisture. Remove receiver-drier and condenser assembly. Remove
receiver-drier from condenser.
Installation
To install, reverse removal procedure. Fill radiator.
Evacuate, leak test, recharge and check A/C system operation.
RECEIVER-DRIER
NOTE: On Cherokee, Comanche and Wagoneer, receiver-drier is
removed with condenser and radiator as an assembly.
Removal (Wrangler)

Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
Wire lead conductors
exposed ................ B .. Require repair or replacement.
Wire lead corroded ...... A .. Require repair or replacement.
Wire lead open .......... A .. Require repair or replacement.
Wire lead shorted ....... A .. Require repair or replacement.
(1) - Refer to manufacturer's diagnostic trouble code
procedure and require repair or replacement of
affected component(s).
( 2) - Determine cause and correct prior to repair or
replacement of part.
( 3) - Determine source of contamination, such as engine coolant,
fuel, metal particles, or water. Require repair or
replacement. Check for accepted cleaning procedure.
( 4) - Inoperative includes intermittent operation or out of
OEM specification. Some components may be serviceable.
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COOLANT
COOLANT INSPECTION \
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Condition Code Procedure
Acidity (pH) incorrect .. 1 ........... Suggest correction or
replacement.
Contaminated ............ B ...... ( 1) Require replacement or
recycling. Further
inspection required.
Level incorrect ......... B .......... ( 2) Require filling to
proper level.
Maintenance intervals ... 3 ........ ( 3) Suggest replacement.
Mixture incorrect ....... B ........... Require correction or
replacement.
Type incorrect .......... B ............ Require replacement.
( 1) - Determine source of contamination and require correction
prior to coolant replacement.
( 2) - Determine source of incorrect level and suggest repair.
( 3) - The system should be drained and/or flushed and
refilled with correct coolant according to OEM
recommended service interval and procedures.
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COOLING FAN BLADES
COOLING FAN BLADE INSPECTION \
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Condition Code Procedure
Application incorrect ... B ............ Require replacement.
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.