Vacuum JEEP LIBERTY 2002 KJ / 1.G User Guide

BRAKES
TABLE OF CONTENTS
page page
POWER BRAKE BOOSTER
REMOVAL - RHD........................1INSTALLATION - RHD.....................1
POWER BRAKE BOOSTER
REMOVAL - RHD
(1) Remove the air box (Refer to 9 - ENGINE/AIR
INTAKE SYSTEM/AIR CLEANER ELEMENT -
REMOVAL).
(2) Relocate the cruise control servo to gain access
to the booster for removal.
(3) Remove the brake lines from the master cylin-
der.
(4) Remove the master cylinder (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/MASTER
CYLINDER - REMOVAL).
(5) Disconnect vacuum hose from booster check
valve.
(6) Remove knee blocker under the steering colum-
n,(Refer to 23 - BODY/INSTRUMENT PANEL/KNEE
BLOCKER - REMOVAL).
(7) Remove the brake light switch.(Refer to 8 -
ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/
BRAKE LAMP SWITCH - REMOVAL)
(8) Remove retaining clip that secures booster
push rod to brake pedal (Fig. 1).
(9) Remove nuts attaching booster to the dash
panel (Fig. 2).(10) In engine compartment, slide booster studs
out of dash panel, tilt booster upward, and remove
booster from engine compartment.
INSTALLATION - RHD
(1) Align and position booster on the dash panel.
(2) Install booster mounting nuts. Tighten nuts
just enough to hold booster in place.
(3) Slide booster push rod onto the brake pedal.
Then secure push rod to pedal pin with retaining
clip.
NOTE: Lubricate the pedal pin with Mopar multi-
mileage grease before installation.
(4) Tighten booster mounting nuts to 39 N´m (29
ft. lbs.).
(5) Install the brake light switch.
(6) Install the knee blocker,(Refer to 23 - BODY/
INSTRUMENT PANEL/KNEE BLOCKER - INSTAL-
LATION).
(7) If original master cylinder is being installed,
check condition of seal at rear of master cylinder.
Replace seal if cut, or torn.
(8) Clean cylinder mounting surface of brake
booster. Use shop towel wetted with brake cleaner for
Fig. 1 BOOSTER PUSH ROD
1 - BRAKE PEDAL
2 - BOOSTER ROD
Fig. 2 BOOSTER MOUNTING
1 - BRAKE BOOSTER
KJBRAKES 5s - 1

this purpose. Dirt, grease, or similar materials will
prevent proper cylinder seating and could result in
vacuum leak.
(9) Align and install master cylinder on the
booster studs. Install mounting nuts and tighten to
17.5 N´m (155 in. lbs.).
(10) Connect vacuum hose to booster check valve.
(11) Remount the cruise control servo to the origi-
nal location. Tighten bracket mounting nuts to 17.5
N´m (155 in. lbs.).(12) Connect and secure the brake lines to HCU
and master cylinder. Start all brake line fittings by
hand to avoid cross threading.
(13) Connect the wire to fluid reservoir.
(14) Install the air box.
(15) Fill and bleed base brake system,(Refer to 5 -
BRAKES - STANDARD PROCEDURE).
(16) Verify proper brake operation before moving
vehicle.
5s - 2 BRAKESKJ
POWER BRAKE BOOSTER (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
HOSE OR HOSES COLLAPSE
WHILE ENGINE IS RUNNING1. Vacuum created in cooling
system on engine cool-down is not
being relieved through coolant
reserve/overflow system.1. (a) Radiator cap relief valve
stuck. (Refer to 7 - COOLING/
ENGINE/RADIATOR PRESSURE
CAP - DIAGNOSIS AND TESTING).
Replace if necessary
(b) Hose between coolant
reserve/overflow tank and radiator is
kinked. Repair as necessary.
(c) Vent at coolant reserve/overflow
tank is plugged. Clean vent and
repair as necessary.
(d) Reserve/overflow tank is
internally blocked or plugged. Check
for blockage and repair as
necessary.
NOISY VISCOUS FAN/DRIVE 1. Fan blades loose - 4.0L. 1. Replace fan blade assembly.
(Refer to 7 - COOLING/ENGINE/
RADIATOR FAN - REMOVAL)
2. Fan blades striking a surrounding
object.2. Locate point of fan blade contact
and repair as necessary.
3. Air obstructions at radiator or air
conditioning condenser.3. Remove obstructions and/or
clean debris or insects from radiator
or A/C condenser.
4. Thermal viscous fan drive has
defective bearing - 4.0L4. Replace fan drive. Bearing is not
serviceable. (Refer to 7 - COOLING/
ENGINE/RADIATOR FAN -
REMOVAL).
INADEQUATE HEATER
PERFORMANCE. THERMOSTAT
FAILED IN OPEN POSITION1. Has a Diagnostic trouble Code
(DTC) been set?1. (Refer to 25 - EMISSIONS
CONTROL - DESCRIPTION) for
correct procedures and replace
thermostat if necessary
2. Coolant level low 2. (Refer to 7 - COOLING -
DIAGNOSIS AND TESTING).
3. Obstructions in heater hose/
fittings3. Remove heater hoses at both
ends and check for obstructions
4. Heater hose kinked 4. Locate kinked area and repair as
necessary
5. Water pump is not pumping
water to/through the heater core.
When the engine is fully warmed
up, both heater hoses should be
hot to the touch. If only one of the
hoses is hot, the water pump may
not be operating correctly or the
heater core may be plugged.
Accessory drive belt may be
slipping causing poor water pump
operation.5. (Refer to 7 - COOLING/ENGINE/
WATER PUMP - DIAGNOSIS AND
TESTING). If a slipping belt is
detected, (Refer to 7 - COOLING/
ACCESSORY DRIVE/DRIVE BELTS
- REMOVAL). If heater core
obstruction is detected, (Refer to 7 -
COOLING - STANDARD
PROCEDURE) for cooling system
reverse flushing.
7 - 10 COOLINGKJ
COOLING (Continued)

STANDARD PROCEDURE
STANDARD PROCEDURE - DRAINING COOLING
SYSTEM 3.7L ENGINE
WARNING: DO NOT REMOVE THE CYLINDER
BLOCK DRAIN PLUGS (Fig. 5) OR LOOSEN THE
RADIATOR DRAINCOCK WITH SYSTEM HOT AND
UNDER PRESSURE. SERIOUS BURNS FROM
COOLANT CAN OCCUR.
(1) DO NOT remove radiator cap first. With engine
cold, raise vehicle on a hoist and locate radiator
draincock.
NOTE: Radiator draincock is located on the left/
lower side of radiator facing to rear of vehicle.
(2) Attach one end of a hose to the draincock. Put
the other end into a clean container. Open draincock
and drain coolant from radiator. This will empty the
coolant reserve/overflow tank. The coolant does not
have to be removed from the tank unless the system
is being refilled with a fresh mixture. When tank is
empty, remove radiator cap and continue draining
cooling system.
STANDARD PROCEDURE - REFILLING
COOLING SYSTEM 3.7L ENGINE
(1) Tighten the radiator draincock and the cylinder
block drain plug(s) (if removed).CAUTION: Failure to purge air from the cooling sys-
tem can result in an overheating condition and
severe engine damage.
(2) .Fill system using a 50/50 mixture of ethylene-
glycol antifreeze and low mineral content water.Fill
pressure bottle to service line.and install cap.
NOTE: The engine cooling system will push any
remaining air into the coolant bottle within about an
hour of normal driving. As a result, a drop in cool-
ant level in the pressure bottle may occur. If the
engine cooling system overheats and pushes cool-
ant into the overflow side of the coolant bottle, this
coolant will be sucked back into the cooling system
ONLY IF THE PRESSURE CAP IS LEFT ON THE
BOTTLE. Removing the pressure cap breaks the
vacuum path between the two bottle sections and
the coolant will not return to cooling system.
(3) With heater control unit in the HEAT position,
operate engine with pressure bottle cap in place.
(4) Add coolant to pressure bottle as necessary.
Only add coolant to the pressure bottle when
the engine is cold. Coolant level in a warm
engine will be higher due to thermal expansion.
NOTE: The coolant bottle has two chambers. Cool-
ant will normally only be in the outboard (larger) of
the two. The inboard chamber is only to recover
coolant in the event of an overheat or after a recent
service fill. The inboard chamber should normally
be empty. If there is coolant in the overflow side of
the coolant bottle (after several warm/cold cycles of
the engine) and coolant level is above cold full
when cold, disconnect the end of the overflow hose
at the fill neck and lower it into a clean container.
Allow coolant to drain into the container until emp-
tied. Reconnect overflow hose to fill neck.
STANDARD PROCEDURE - COOLING SYSTEM -
REVERSE FLUSHING
CAUTION: The cooling system normally operates at
97-to-110 kPa (14-to -16 psi) pressure. Exceeding
this pressure may damage the radiator or hoses.
Reverse flushing of the cooling system is the forc-
ing of water through the cooling system. This is done
using air pressure in the opposite direction of normal
coolant flow. It is usually only necessary with very
dirty systems with evidence of partial plugging.
CHEMICAL CLEANING
If visual inspection indicates the formation of
sludge or scaly deposits, use a radiator cleaner
Fig. 5 Drain Plug - 3.7L Engine
1 - CYLINDER BLOCK DRAIN PLUG
2 - EXHAUST MANIFOLD AND HEAT SHIELD
7 - 12 COOLINGKJ
COOLING (Continued)

ENGINE
TABLE OF CONTENTS
page page
COOLANT RECOVERY PRESS CONTAINER
DESCRIPTION.........................19
OPERATION...........................19
ENGINE COOLANT TEMPERATURE SENSOR
DESCRIPTION.........................19
OPERATION...........................20
REMOVAL.............................20
INSTALLATION.........................21
ENGINE COOLANT THERMOSTAT
DESCRIPTION - 3.7L ENGINE.............21
OPERATION...........................21
DIAGNOSIS AND TESTING - THERMOSTAT . . . 21
REMOVAL - 3.7L ENGINE.................21
INSTALLATION - 3.7L ENGINE.............22
RADIATOR
DESCRIPTION.........................22
REMOVAL.............................23
CLEANING............................24
INSPECTION..........................24
INSTALLATION.........................24
RADIATOR PRESSURE CAP
DESCRIPTION.........................25
OPERATION...........................25
DIAGNOSIS AND TESTING - RADIATOR
PRESSURE CAP......................25CLEANING............................25
INSPECTION..........................25
RADIATOR FAN - ELECTRIC
DESCRIPTION.........................26
OPERATION...........................26
REMOVAL.............................26
INSTALLATION.........................27
RADIATOR - FAN - VISCOUS
DESCRIPTION.........................27
OPERATION...........................27
DIAGNOSIS AND TESTING - VISCOUS FAN
DRIVE..............................28
REMOVAL.............................28
CLEANING............................29
INSPECTION..........................29
INSTALLATION.........................29
WATER PUMP
DESCRIPTION
DESCRIPTION - WATER PUMP...........29
DESCRIPTION........................29
OPERATION - WATER PUMP..............30
REMOVAL.............................30
CLEANING............................31
INSPECTION..........................31
INSTALLATION.........................31
COOLANT RECOVERY PRESS
CONTAINER
DESCRIPTION
This system works along with the radiator pres-
sure cap. This is done by using thermal expansion
and contraction of the coolant to keep the coolant
free of trapped air. It provides:
²A volume for coolant expansion and contraction.
²A convenient and safe method for checking/ad-
justing coolant level at atmospheric pressure. This is
done without removing the radiator pressure cap.
²Some reserve coolant to the radiator to cover
minor leaks and evaporation or boiling losses.
As the engine cools, a vacuum is formed in the
cooling system of both the radiator and engine. Cool-
ant will then be drawn from the coolant tank and
returned to a proper level in the radiator.
The coolant reservoir/overflow system has a radia-
tor mounted pressurized cap, an overflow tube, and a
plastic coolant reservoir/overflow tank, mounted to
the right side of the cowl. It is mounted to the cowlwith two nuts on top, and a slide bracket on the bot-
tom.
OPERATION
The pressure chamber keeps the coolant free of
trapped air, provides a volume for expansion and con-
traction, and provides a convenient and safe method
for checking and adjusting coolant level at atmo-
spheric pressure. It also provides some reserve cool-
ant to cover minor leaks, evaporation or boiling
losses. The overflow chamber allows coolant recovery
in case of an overheat.
ENGINE COOLANT
TEMPERATURE SENSOR
DESCRIPTION
The Engine Coolant Temperature (ECT) sensor is
used to sense engine coolant temperature. The sensor
protrudes into an engine water jacket.
KJENGINE 7 - 19

RADIATOR PRESSURE CAP
DESCRIPTION
The cooling system cap is located on the coolant
pressure bottle. The cap construction includes; stain-
less steel swivel top, rubber seals and retainer, main
spring, and a spring loaded valve (Fig. 10).
OPERATION
The pressure cap allows the cooling system to oper-
ate at higher than atmospheric pressure which raises
the coolant boiling point, thus allowing increased
radiator cooling capacity. The pressure cap releases
pressure at some point within a range of 110 kPa  
14 kPa (16 psi   2 psi).
A spring-loaded vent valve in the center of the cap
allows the system to pressurize and depressurize
without creating a vacuum. If the valve is stuck
open, coolant will escape to the overflow hose. There
is also a gasket in the cap to seal to the top of the
filler neck.
CAUTION: Use only the pressure cap specified for
this vehicle. Use of other pressure caps can lead to
coolant loss and overheating.
DIAGNOSIS AND TESTING - RADIATOR
PRESSURE CAP
Remove cap from radiator. Be sure that sealing
surfaces are clean. Moisten rubber gasket with water
and install the cap on pressure tester (tool 7700 or
an equivalent) (Fig. 11).Operate the tester pump and observe the gauge
pointer at its highest point. The cap release pressure
should be 124 to 145 kPa (18 to 21 psi). The cap is
satisfactory when the pressure holds steady. It is also
good if it holds pressure within the 124 to 145 kPa
(18 to 21 psi) range for 30 seconds or more. If the
pointer drops quickly, replace the cap.
CAUTION: Radiator pressure testing tools are very
sensitive to small air leaks, which will not cause
cooling system problems. A pressure cap that does
not have a history of coolant loss should not be
replaced just because it leaks slowly when tested
with this tool. Add water to tool. Turn tool upside
down and recheck pressure cap to confirm that cap
needs replacement.
CLEANING
Clean the radiator pressure cap using a mild soap
and water only.
INSPECTION
Visually inspect the pressure valve gasket on the
cap. Replace cap if the gasket is swollen, torn or
worn. Inspect the area around radiator filler neck for
white deposits that indicate a leaking cap.
Fig. 10 PRESSURE CAP
1 - MAIN SPRING
2 - GASKET RETAINER
3 - STAINLESS STEEL SWIVEL TOP
4 - RUBBER SEALS
5 - SPRING LOADED VALVE
6 - COOLANT PRESSURE BOTTLE
7 - FILLER NECK
8 - OVERFLOW NIPPLEFig. 11 Pressure Testing Radiator Pressure Cap -
Typical
1 - PRESSURE CAP
2 - TYPICAL COOLING SYSTEM PRESSURE TESTER
KJENGINE 7 - 25

CONDITION POSSIBLE CAUSES CORRECTION
COOLANT LOSS TO THE
GROUND WITHOUT PRESSURE
CAP BLOWOFF. GAUGE READING
HIGH OR HOT1. Coolant leaks in radiator, cooling
system hoses, water pump or
engine.1. Pressure test and repair as
necessary. (Refer to 7 - COOLING -
DIAGNOSIS AND TESTING).
DETONATION OR PRE-IGNITION
(NOT CAUSED BY IGNITION
SYSTEM). GAUGE MAY OR MAY
NOT BE READING HIGH1. Engine overheating. 1. Check reason for overheating
and repair as necessary.
2. Freeze point of coolant not
correct. Mixture is too rich or too
lean.2. Check coolant concentration.
(Refer to 7 - COOLING/ENGINE/
COOLANT - DESCRIPTION) and
adjust ratio as required.
HOSE OR HOSES COLLAPSE
WHILE ENGINE IS RUNNING1. Vacuum created in cooling
system on engine cool-down is not
being relieved through coolant
reserve/overflow system.1. (a) Radiator cap relief valve
stuck. (Refer to 7 - COOLING/
ENGINE/RADIATOR PRESSURE
CAP - DIAGNOSIS AND TESTING).
Replace if necessary
(b) Hose between coolant
reserve/overflow tank and radiator is
kinked. Repair as necessary.
(c) Vent at coolant reserve/overflow
tank is plugged. Clean vent and
repair as necessary.
(d) Reserve/overflow tank is
internally blocked or plugged. Check
for blockage and repair as
necessary.
NOISY VISCOUS FAN/DRIVE 1. Fan blades loose. 1. Replace fan blade assembly.
(Refer to 7 - COOLING/ENGINE/
RADIATOR FAN - REMOVAL)
2. Fan blades striking a surrounding
object.2. Locate point of fan blade contact
and repair as necessary.
3. Air obstructions at radiator or air
conditioning condenser.3. Remove obstructions and/or
clean debris or insects from radiator
or A/C condenser.
4. Thermal viscous fan drive has
defective bearing.4. Replace fan drive. Bearing is not
serviceable. (Refer to 7 - COOLING/
ENGINE/RADIATOR FAN -
REMOVAL).
KJCOOLING - 2.4L7s-9
COOLING - 2.4L (Continued)

NOTE: The engine cooling system will push any
remaining air into the coolant bottle within about an
hour of normal driving. As a result, a drop in cool-
ant level in the pressure bottle may occur. If the
engine cooling system overheats and pushes cool-
ant into the overflow side of the coolant bottle, this
coolant will be sucked back into the cooling system
ONLY IF THE PRESSURE CAP IS LEFT ON THE
BOTTLE. Removing the pressure cap breaks the
vacuum path between the two bottle sections and
the coolant will not return to cooling system.
(3) With heater control unit in the HEAT position,
operate engine with pressure bottle cap in place.
(4) Add coolant to pressure bottle as necessary.
Only add coolant to the pressure bottle when
the engine is cold. Coolant level in a warm
engine will be higher due to thermal expansion.
NOTE: The coolant bottle has two chambers. Cool-
ant will normally only be in the outboard (larger) of
the two. The inboard chamber is only to recover
coolant in the event of an overheat or after a recent
service fill. The inboard chamber should normally
be empty. If there is coolant in the overflow side of
the coolant bottle (after several warm/cold cycles of
the engine) and coolant level is above cold full
when cold, disconnect the end of the overflow hose
at the fill neck and lower it into a clean container.
Allow coolant to drain into the container until emp-
tied. Reconnect overflow hose to fill neck.
STANDARD PROCEDURE - COOLING SYSTEM -
REVERSE FLUSHING
CAUTION: The cooling system normally operates at
97-to-110 kPa (14-to -16 psi) pressure. Exceeding
this pressure may damage the radiator or hoses.
Reverse flushing of the cooling system is the forc-
ing of water through the cooling system. This is done
using air pressure in the opposite direction of normal
coolant flow. It is usually only necessary with very
dirty systems with evidence of partial plugging.
CHEMICAL CLEANING
If visual inspection indicates the formation of
sludge or scaly deposits, use a radiator cleaner
(Mopar Radiator Kleen or equivalent) before flushing.
This will soften scale and other deposits and aid the
flushing operation.
CAUTION: Be sure instructions on the container are
followed.
REVERSE FLUSHING RADIATOR
Disconnect the radiator hoses from the radiator fit-
tings. Attach a section of radiator hose to the radia-
tor bottom outlet fitting and insert the flushing gun.
Connect a water supply hose and air supply hose to
the flushing gun.
CAUTION: The cooling system normally operates at
97-to-110 kPa (14- to-16 psi) pressure. Exceeding
this pressure may damage the radiator or hoses.
Allow the radiator to fill with water. When radiator
is filled, apply air in short blasts allowing radiator to
refill between blasts. Continue this reverse flushing
until clean water flows out through rear of radiator
cooling tube passages. For more information, refer to
operating instructions supplied with flushing equip-
ment. Have radiator cleaned more extensively by a
radiator repair shop.
REVERSE FLUSHING ENGINE
Drain the cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE). Remove the thermostat
housing and thermostat. Install the thermostat hous-
ing. Disconnect the radiator upper hose from the
radiator and attach the flushing gun to the hose. Dis-
connect the radiator lower hose from the water
pump. Attach a lead away hose to the water pump
inlet fitting.
CAUTION: Be sure that the heater control valve is
closed (heat off). This is done to prevent coolant
flow with scale and other deposits from entering
the heater core.
Connect the water supply hose and air supply hose
to the flushing gun. Allow the engine to fill with
water. When the engine is filled, apply air in short
blasts, allowing the system to fill between air blasts.
Continue until clean water flows through the lead
away hose. For more information, refer to operating
instructions supplied with flushing equipment.
Remove the lead away hose, flushing gun, water
supply hose and air supply hose. Remove the thermo-
stat housing (Refer to 7 - COOLING/ENGINE/EN-
GINE COOLANT THERMOSTAT - REMOVAL).
Install the thermostat and housing with a replace-
ment gasket (Refer to 7 - COOLING/ENGINE/EN-
GINE COOLANT THERMOSTAT -
INSTALLATION). Connect the radiator hoses. Refill
the cooling system with the correct antifreeze/water
mixture (Refer to 7 - COOLING - STANDARD PRO-
CEDURE).
7s - 12 COOLING - 2.4LKJ
COOLING - 2.4L (Continued)

Propylene-glycol/ethylene-glycol Mixtures can
cause the destabilization of various corrosion inhibi-
tors, causing damage to the various cooling system
components. Also, once ethylene-glycol and propy-
lene-glycol based coolants are mixed in the vehicle,
conventional methods of determining freeze point will
not be accurate. Both the refractive index and spe-
cific gravity differ between ethylene glycol and propy-
lene glycol.
OPERATION
Coolant flows through the engine block absorbing
the heat from the engine, then flows to the radiator
where the cooling fins in the radiator transfers the
heat from the coolant to the atmosphere. During cold
weather the ethylene-glycol coolant prevents water
present in the cooling system from freezing within
temperatures indicated by mixture ratio of coolant to
water.
COOLANT RECOVERY PRESS
CONTAINER
DESCRIPTION
This system works along with the radiator pres-
sure cap. This is done by using thermal expansion
and contraction of the coolant to keep the coolant
free of trapped air. It provides:
²A volume for coolant expansion and contraction.
²A convenient and safe method for checking/ad-
justing coolant level at atmospheric pressure. This is
done without removing the radiator pressure cap.
²Some reserve coolant to the radiator to cover
minor leaks and evaporation or boiling losses.
As the engine cools, a vacuum is formed in the
cooling system of both the radiator and engine. Cool-
ant will then be drawn from the coolant tank and
returned to a proper level in the radiator.
The coolant reservoir/overflow system has a radia-
tor mounted pressurized cap, an overflow tube, and a
plastic coolant reservoir/overflow tank, mounted to
the right side of the cowl. It is mounted to the cowl
with two nuts on top, and a slide bracket on the bot-
tom.
OPERATION
The pressure chamber keeps the coolant free of
trapped air, provides a volume for expansion and con-
traction, and provides a convenient and safe method
for checking and adjusting coolant level at atmo-
spheric pressure. It also provides some reserve cool-
ant to cover minor leaks, evaporation or boiling
losses. The overflow chamber allows coolant recovery
in case of an overheat.
ENGINE BLOCK HEATER - 2.4L
DESCRIPTION
The block heater is operated by ordinary house
current (110 Volt A.C.) through a power cord and con-
nector located in the engine compartment. The
heater is mounted in a core hole (in place of a core
hole plug) in the engine block, with the heating ele-
ment immersed in coolant.
CAUTION: The power cord must be secured in its
retainer clips, and not positioned so it could con-
tact linkages or exhaust manifolds and become
damaged.
OPERATION
The block heater element is submerged in the cool-
ing system's coolant. When electrical power (110 volt
A.C.) is applied to the element, it creates heat. This
heat is transferred to the engine coolant. This pro-
vides easier engine starting and faster warm-up
when vehicle is operated in areas having extremely
low temperatures.
REMOVAL - 2.4L
(1) Drain cooling system (Refer to 7 - COOLING/
ENGINE - STANDARD PROCEDURE).
(2) Raise vehicle on hoist.
(3) Detach power cord plug from heater.
(4) Loosen screw in center of heater. Remove
heater assembly.
INSTALLATION - 2.4L
(1) Thoroughly clean core hole and heater seat.
(2) Insert heater assembly (Fig. 1) with element
loop positionedupward.
(3) With heater seated, tighten center screw
securely to assure a positive seal.
CAUTION: To prevent damage, the power cord must
be secured in it's retaining clips, and not positioned
so it could contact linkages or exhaust manifold.
(4) Connect power cord to heater.
(5) Lower vehicle.
(6) Fill cooling system (Refer to 7 - COOLING/EN-
GINE - STANDARD PROCEDURE).
7s - 20 ENGINEKJ
COOLANT (Continued)

RADIATOR PRESSURE CAP
DESCRIPTION
The cooling system cap is located on the coolant
pressure bottle. The cap construction includes; stain-
less steel swivel top, rubber seals and retainer, main
spring, and a spring loaded valve (Fig. 9).
OPERATION
The pressure cap allows the cooling system to oper-
ate at higher than atmospheric pressure which raises
the coolant boiling point, thus allowing increased
radiator cooling capacity. The pressure cap releases
pressure at some point within a range of 110 kPa  
14 kPa (16 psi   2 psi).
A spring-loaded vent valve in the center of the cap
allows the system to pressurize and depressurize
without creating a vacuum. If the valve is stuck
open, coolant will escape to the overflow hose. There
is also a gasket in the cap to seal to the top of the
filler neck.
CAUTION: Use only the pressure cap specified for
this vehicle. Use of other pressure caps can lead to
coolant loss and overheating.
DIAGNOSIS AND TESTING - RADIATOR
PRESSURE CAP
Remove cap from radiator. Be sure that sealing
surfaces are clean. Moisten rubber gasket with water
and install the cap on pressure tester (tool 7700 or
an equivalent) (Fig. 10).Operate the tester pump and observe the gauge
pointer at its highest point. The cap release pressure
should be 124 to 145 kPa (18 to 21 psi). The cap is
satisfactory when the pressure holds steady. It is also
good if it holds pressure within the 124 to 145 kPa
(18 to 21 psi) range for 30 seconds or more. If the
pointer drops quickly, replace the cap.
CAUTION: Radiator pressure testing tools are very
sensitive to small air leaks, which will not cause
cooling system problems. A pressure cap that does
not have a history of coolant loss should not be
replaced just because it leaks slowly when tested
with this tool. Add water to tool. Turn tool upside
down and recheck pressure cap to confirm that cap
needs replacement.
CLEANING
Clean the radiator pressure cap using a mild soap
and water only.
INSPECTION
Visually inspect the pressure valve gasket on the
cap. Replace cap if the gasket is swollen, torn or
worn. Inspect the area around radiator filler neck for
white deposits that indicate a leaking cap.
Fig. 9 PRESSURE CAP
1 - MAIN SPRING
2 - GASKET RETAINER
3 - STAINLESS STEEL SWIVEL TOP
4 - RUBBER SEALS
5 - SPRING LOADED VALVE
6 - COOLANT PRESSURE BOTTLE
7 - FILLER NECK
8 - OVERFLOW NIPPLEFig. 10 Pressure Testing Radiator Pressure Cap -
Typical
1 - PRESSURE CAP
2 - TYPICAL COOLING SYSTEM PRESSURE TESTER
KJENGINE7s-25