1998 NISSAN PATROL Radiator hose

Special Service Tools*: Special tool or commercial equivalent
Tool number
Tool nameDescription
ST25051001*
Oil pressure gauge
NT558
Measuring oil pressure
Maximum measuring range:
2,452 kPa (24.5 bar, 25
kg/cm
2, 356 psi)
ST25052000*
Hose
NT559
Adapting oil pressure gauge
to cylinder block
EG17650301
Radiator cap tester
adapter
NT564
Adapting radiator cap tester
to radiator ®ller neck
a: 28 (1.10) dia.
b: 31.4 (1.236) dia.
c: 41.3 (1.626) dia.
Unit: mm (in)
KV99103510
Radiator plate pliers A
NT224
Installing radiator upper and
lower tanks
KV99103520
Radiator plate pliers B
NT225
Removing radiator upper and
lower tanks
WS39930000
Tube presser
NT052
Pressing the tube of liquid gas-
ket
PRECAUTIONS AND PREPARATION
LC-2

Cooling Circuit
System Check
WARNING:
Never remove the radiator cap when the engine is hot; serious
burns could be caused by high pressure ¯uid escaping from
the radiator.
Wrap a thick cloth around cap and carefully loosen it a quar-
ter turn to release built-up pressure. Then remove the cap
completely.
CHECKING COOLING SYSTEM HOSES
Check hoses for proper attachment, leaks, cracks, damage, loose
connections, cha®ng and deterioration.
CHECKING RADIATOR CAP
Apply pressure to radiator cap by means of a cap tester to see if it
is satisfactory.
Radiator cap relief pressure:
78-98kPa
(0.78 - 0.98 bar, 0.8 - 1.0 kg/cm
2, 11 - 14 psi)
SLC226A
SLC613
ENGINE COOLING SYSTEM
LC-9

Pull the negative pressure valve to open it. Check that it closes
completely when released.
CHECKING COOLING SYSTEM FOR LEAKS
Apply pressure to the cooling system by means of a tester to check
for leakage.
Testing pressure:
98 kPa (0.98 bar, 1.0 kg/cm
2, 14 psi)
CAUTION:
Use of pressure higher than the speci®ed value may cause
damage to radiator.
Water Pump
CAUTION:
+When removing water pump assembly, be careful not to
get coolant on drive belts.
+Water pump cannot be disassembled and should be
replaced as a unit.
+After installing water pump, connect hose and clamp
securely, then check for leaks using radiator cap tester.
REMOVAL
1. Drain coolant from radiator and cylinder block.
Cylinder block drain plug (Use proper sealant):
:34-44Nzm (3.5 - 4.5 kg-m, 25 - 33 ft-lb)
Refer to MA section (``Changing Engine Coolant'', ``ENGINE
MAINTENANCE'').
2. Remove radiator shroud.
3. Remove drive belts. Refer to MA section (``Checking Drive
Belts'').
4. Remove fan coupling with fan.
5. Remove water pump.
SMA967B
SMA007D
SMA003D
ENGINE COOLING SYSTEM
System Check (Cont'd)
LC-10

Radiator
REMOVAL AND INSTALLATION
1. Remove under cover.
2. Drain coolant from radiator drain plug.
3. Disconnect radiator upper and lower hoses.
4. Remove radiator lower shroud.
5. Disconnect reservoir tank hose.
6. Remove radiator.
7. After repairing or replacing radiator, install any part removed in
reverse order of removal.
Re®lling Engine Coolant
For details on re®lling engine coolant, refer to MA section (``REFILL-
ING ENGINE COOLANT'', ``Changing Engine Coolant'').
SLC198B
ENGINE COOLING SYSTEM
LC-14

INSPECTION
1. Apply pressure with Tool.
Speci®ed pressure value:
98 kPa (0.98 bar, 1.0 kg/cm
2, 14 psi)
WARNING:
To prevent the risk of the hose coming undone while under
pressure, securely fasten it down with a hose clamp.
Attach a hose to the oil cooler as well.
2. Check for leakage.
SLC933
SLC934
ENGINE COOLING SYSTEM
Radiator (Aluminum type) (Cont'd)
LC-19

Overheating Cause Analysis
Symptom Check items
Cooling
system parts
malfunctionPoor heat transferWater pump malfunction Worn or loose drive belt
Ð Thermostat stuck closed Ð
Damaged ®nsDust contamination or paper
clogging
Mechanical damage
Clogged radiator cooling tubeExcess foreign material (rust,
dirt, sand, etc.)
Reduced air ¯owCooling fan does not operate
ÐÐ Fan coupling does not operate
High resistance to fan rotation
Damaged fan blades
Damaged radiator shroud Ð Ð Ð
Improper coolant mixture ratio Ð Ð Ð
Poor coolant quality Ð Ð Ð
Insufficient coolantCoolant leaksCooling hoseLoose clamp
Cracked hose
Water pump Poor sealing
Radiator capLoose
Poor sealing
RadiatorO-ring for damage, deteriora-
tion or improper ®tting
Cracked radiator tank
Cracked radiator core
Reservoir tank Cracked reservoir tank
Over¯owing reservoir tankExhaust gas leaks into cooling
systemCylinder head deterioration
Cylinder head gasket deteriora-
tion
Except
cooling
system parts
malfunctionÐ Overload on engineAbusive drivingHigh engine rpm under no load
Driving in low gear for extended
time
Driving at extremely high speed
Powertrain system malfunction
Ð Installed improper size wheels
and tires
Dragging brakes
Improper ignition timing
Blocked or restricted air ¯owBlocked bumper Ð
Ð Blocked radiator grilleInstalled car brassiere
Mud contamination or paper
clogging
Blocked radiator Ð
Blocked condenser
Ð
Installed large fog lamp
ENGINE COOLING SYSTEM
LC-20