Page 2545 of 2898

+Replace the radiator cap if abnormalities are found with the
negative pressure valve, or if the valve opening pressure is out
of the standard range.
SLC756AA
CHECKING COOLING SYSTEM FOR LEAKSNJLC0054S04To check for leakage, apply pressure to the cooling system with a
tester.
Testing pressure:
157 kPa (1.57 bar, 1.6 kg/cm
2, 23 psi)
CAUTION:
+Higher than the specified pressure may cause radiator
damage.
+Be sure to perform the inspections after cooling down the
engine.
+Use a hose adapter between the cap tester and filler neck
to prevent the radiator filler neck from deforming.
+If any abnormalities are found, repair or replace the malfunc-
tioning parts.
Water Pump
REMOVAL AND INSTALLATIONNJLC0055CAUTION:
+When removing water pump assembly, be careful not to
get coolant on drive belt.
+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.
ENGINE COOLING SYSTEMYD
System Check (Cont'd)
LC-39
Page 2546 of 2898
JLC294B
REMOVALNJLC00561. Remove the undercover, splash cover (right), and accessory
belt.
2. Drain engine coolant. Refer to LC-44, ªChanging Engine Cool-
antº.
3. Support the bottom of the oil pan with a floor jack etc., and
remove the right engine mount bracket (front side of the
engine).
4. Remove the water pump pulley.
+Loosen the pulley bolts after fixing the pulley using a screw-
driver etc.
5. Remove engine mount brackets.
6. Remove the water pump.
INSPECTIONNJLC0057+Check for rust and contamination adhering to the water pump
and vane.
+Turn the pump shaft by hand, and check that the pump turns
smoothly without looseness.
INSTALLATIONNJLC0058+Install the parts in the reverse order of removal.
+Install the water pump pulley with the front mark (painted white,
used to prevent errors during assembly) facing the front of the
engine. Refer to the figure above.
ENGINE COOLING SYSTEMYD
Water Pump (Cont'd)
LC-40
Page 2547 of 2898
Thermostat
REMOVAL AND INSTALLATIONNJLC0059
NLC099
+Be careful not to spill coolant over engine compartment.
Use a rag to absorb coolant.
1. Drain engine coolant. Refer to LC-44, ªChanging Engine Cool-
antº.
2. Remove exhaust manifold cover.
3. Remove water inlet.
4. Remove thermostat.
JLC300B
5. Install thermostat with jiggle valve facing upward.
+Carefully install the rubber ring to the flange of the
thermostat, making sure it does not slip out of place.
6. After installation and refilling coolant, run engine for a few
minutes, and check for leaks.
ENGINE COOLING SYSTEMYD
Thermostat
LC-41
Page 2548 of 2898
SLC252B
INSPECTIONNJLC00601. Check valve seating condition at ordinary room temperatures.
It should seat tightly.
2. Check valve opening temperature and maximum valve lift.
Standard
Valve opening temperature Above 80.5 - 83.5ÉC (177 - 182ÉF)
Valve lift More than 9 mm/95ÉC
(0.354 in/203ÉF)
3. Then check if valve closes at 5ÉC (9ÉF) below valve opening
temperature.
Radiator
COMPONENTSNJLC0083
SLC430B
ENGINE COOLING SYSTEMYD
Thermostat (Cont'd)
LC-42
Page 2549 of 2898
REMOVAL AND INSTALLATION=NJLC00631. Remove under cover.
2. For Sedan, drain coolant from radiator by drain cock, and for
Hatchback, drain coolant by removing lower radiator hose.
3. Disconnect radiator upper and lower hoses.
4. Remove radiator shroud.
5. Disconnect reservoir tank hose.
6. Remove radiator mounting bracket.
7. Remove radiator.
8. After repairing or replacing radiator, install any part removed in
reverse order of removal.
When filling radiator with coolant, refer to LC-44, ªChanging
Engine Coolantº.
Cooling FanNJLC0064COMPONENTSNJLC0064S01
JLC347B
CONTROL SYSTEMNJLC0064S02Cooling fans are controlled by ECM. For details, refer to EC-730,
ªTROUBLE DIAGNOSIS FOR OVERHEATº.
ENGINE COOLING SYSTEMYD
Radiator (Cont'd)
LC-43
Page 2550 of 2898

SLC344B
JLC295B
Changing Engine CoolantNJLC0079WARNING:
To avoid the danger of being scalded, never change the cool-
ant when the engine is hot.
Ð DRAINING ENGINE COOLANT ÐNJLC0079S011. Set air conditioning system as follows to prevent coolant from
remaining in the system.
a. Turn ignition switch ON and set temperature controller to maxi-
mum hot position.
b. Wait 10 seconds before turning ignition switch OFF.
SMA033D
2. Open radiator drain cock at the bottom of radiator or remove
lower radiator hose, and remove radiator filler cap to drain
coolant.
3. Remove reservoir tank, drain coolant, then clean reservoir
tank.
+Be careful not to allow coolant to contact drive belts.
4. Cover the exhaust tube heat shield to prevent from splashing
coolant.
JLC429B
SLC341B
5. Remove drain plug of cylinder block and air relief plug.
6. Check drained coolant for contaminants such as rust, corro-
sion or discoloration. If contaminated flush engine cooling
system, refer to LC-46, ªFLUSHING COOLING SYSTEMº.
7. Blow the coolant around the exhaust tube heat shield.
NOTE:
An asterisk (*1) in the figure means ªNot installed on some
modelsº.
ENGINE COOLING SYSTEMYD
Changing Engine Coolant
LC-44
Page 2551 of 2898

JLC298B
Ð REFILLING ENGINE COOLANT ÐNJLC0079S021. Install reservoir tank, radiator drain cock or lower radiator hose
and cylinder block drain plug.
+Apply sealant to the thread of cylinder block drain plugs.
:8-11N´m(0.8 - 1.2 kg-m, 70 - 104 in-lb)
2. Fill radiator slowly with coolant until coolant spills from the air
relief plugs, then install air relief plugs.
+Location of air relief plugs
Water inlet and rear side intake manifold water tubes
3. Disconnect heater hose at engine, pour coolant into the hose
so that it flows toward the heater core.
+While filling, if coolant from engine side spills out, be sure to
reconnect the heater hose.
+Fill coolant to the level of the radiator cap at a rate of 2!(1-3/4
Imp qt)/min or lower.
(Close the air relief plugs in order starting with the location from
where the coolant began spilling out.)
CAUTION:
If the filling rate is too fast, this could lead to air being mixed
in the coolant. Be sure to fill the coolant slowly according to
the rate indicated above.
+Replace the copper washer of the air bleeding plug.
Air relief plug:
: 6.7 - 7.9 N´m (0.68 - 0.81 kg-m, 59 - 70 in-lb)
+Use genuine Nissan anti-freeze coolant or equivalent
mixed with water (distilled or demineralized).
SMA182B
SMA412B
Refer to MA-16, ªRECOMMENDED FLUIDS AND LUBRI-
CANTSº.
Engine coolant capacity (With reservoir tank):
8.7!(7-5/8 Imp qt)
Reservoir tank capacity:
0.7!(5/8 Imp qt)
+Pour coolant through coolant filler neck slowly to allow air
in system to escape.
4. Fill radiator and reservoir tank to specified level.
5. Warm up engine to normal operating temperature without
radiator cap installed.
+If coolant overflows radiator filler hole, install radiator cap.
6. Run engine at 3,000 rpm for 10 seconds and return to idle
speed with radiator cap installed.
+Repeat two or three times.
Watch coolant temperature gauge so as not to overheat the
engine.
7. Stop engine and cool it down.
+Cool down using a fan to reduce the time.
+If necessary, refill radiator up to filler neck with coolant.
8. Refill reservoir tank to MAX level line with coolant.
ENGINE COOLING SYSTEMYD
Changing Engine Coolant (Cont'd)
LC-45
Page 2552 of 2898

9. Repeat steps 4 through 7 two or more times with radiator cap
installed until coolant level no longer drops.
10. Check cooling system for leaks with engine running.
11. Warm up engine, and check for sound of coolant flow while
running engine from idle up to 3,000 rpm with heater tempera-
ture controller set at several positions between COOL and
HOT.
+Sound may be noticeable at heater water cock.
12. If sound is heard, bleed air from cooling system by repeating
steps 4 through 7 until coolant level no longer drops
+Clean excess coolant from engine.
Ð FLUSHING COOLING SYSTEM ÐNJLC0079S031. Open air relief plug.
2. Fill radiator with water until water spills from the air relief hole,
then close air relief plug. Fill radiator and reservoir tank with
water and reinstall radiator cap.
3. Run engine and warm it up to normal operating temperature.
4. Rev engine two or three times under no-load.
5. Stop engine and wait until it cools down.
6. Drain water.
7. Repeat steps 1 through 6 until clear water begins to drain from
radiator.
ENGINE COOLING SYSTEMYD
Changing Engine Coolant (Cont'd)
LC-46