1998 NISSAN PICK-UP Repair Manual

Cooling Circuit
System Check
WARNING:
Never remove the radiator cap when the engine is hot. Seri-
ous burns could occur from high pressure coolant escaping
from the radiator.
Wrap a thick cloth around the cap. Slowly turn it a quarter
turn to allow built-up pressure to escape. Carefully remove
the cap by turning it all the way.
CHECKING COOLING SYSTEM HOSES
Check hoses for the following:
lImproper attachment
lLeaks
lCracks
lDamage
lChafing
lDeterioration
SLC138B
ENGINE COOLING SYSTEMKA
LC-6

CHECKING COOLING SYSTEM FOR LEAKS
To 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 pressure than specified may cause radiator damage.
CHECKING RADIATOR CAP
To check radiator cap, apply pressure to cap with a tester.
Radiator cap relief pressure:
Standard
78-98kPa
(0.78 - 0.98 bar, 0.8 - 1.0 kg/cm
2, 11 - 14 psi)
Limit
59-98kPa
(0.59 - 0.98 bar, 0.6 - 1.0 kg/cm
2,9-14psi)
Pull the negative pressure valve to open it.
Check that it closes completely when released.
Water Pump
CAUTION:
lWhen removing water pump assembly, be careful not to
get coolant on drive belts.
lWater pump cannot be disassembled and should be
replaced as a unit.
lAfter 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.
Refer to MA section (``Changing Engine Coolant'', ``ENGINE
MAINTENANCE'').
2. Remove power steering pump drive belt, generator drive belt
and A/C compressor drive belt.
3. Remove fan coupling with fan.
4. Remove water pump.
SLC134B
SLC135B
SMA967B
ALC060
ENGINE COOLING SYSTEMKA
System Check (Cont'd)
LC-7

INSPECTION
lCheck body assembly for rust or corrosion.
lCheck for rough operation due to excessive end play.
INSTALLATION
1. Use a scraper to remove liquid gasket from water pump.
lAlso remove traces of liquid gasket from mating surface
of cylinder block.
2. Apply a continuous bead of liquid gasket to mating surface
of water pump.
lUse Genuine Liquid Gasket or equivalent.
When filling radiator with coolant, refer to MA section
(``Changing Engine Coolant'', ``ENGINE MAINTENANCE'').
When installing drive belts, refer to MA section (``Checking
Drive Belts'').
Thermostat
lBe careful not to spill coolant over engine compartment.
Use a rag to absorb coolant.
REMOVAL
1. Drain coolant form engine. Refer to MA section (``Changing
Engine Coolant'', ``ENGINE MAINTENANCE'').
2. Remove air cleaner and air duct assembly.
3. Remove water hose from water inlet housing.
4. Remove water inlet housing, then take out thermostat.
INSPECTION
1. Check valve seating condition at normal room temperatures.
It should seat tightly.
2. Check valve opening temperature and valve lift.
Valve opening temperature ÉC (ÉF) 76.5 (170)
Valve lift mm/ÉC (in/ÉF) More than 8/90 (0.31/194)
3. Then check if valve closes at 5ÉC (9ÉF) below valve opening
temperature.
SLC738
SLC188A
SLC391AA
ALC061
SLC343
ENGINE COOLING SYSTEMKA
Water Pump (Cont'd)
LC-8

INSTALLATION
1. Use a scraper to remove old liquid gasket from water inlet.
lAlso remove traces of liquid gasket from mating surface
of front cover.
2. Apply a continuous bead of liquid gasket to mating surface
of water inlet.
lUse Genuine Liquid Gasket or equivalent.
3. Install thermostat with jiggle valve or air bleeder at upper
side.
4. Install water inlet housing.
5. Install water hose to water inlet housing.
6. Install air cleaner and air duct assembly.
7. Refill engine coolant. Refer to MA section (``Changing Engine
Coolant'', ``ENGINE MAINTENANCE'').
lAfter installation run engine for a few minutes, and
check for leaks.
Radiator
REMOVAL AND INSTALLATION
1. Drain coolant from radiator. Refer to MA section (``Changing
Engine Coolant'', ``ENGINE MAINTENANCE'').
2. Disconnect upper and lower radiator hoses.
3. Remove air cleaner and air duct assembly.
4. Remove lower radiator shroud.
5. Remove radiator shroud.
6. Disconnect coolant reservoir hose.
7. Remove radiator.
8. After replacing radiator, install all parts in reverse order of
removal.
9. Refill engine coolant. Refer to MA section (``Changing Engine
Coolant'', ``ENGINE MAINTENANCE'').
lAfter installation, run engine for a few minutes, and
check for leaks.
SLC824-A
SLC097
ENGINE COOLING SYSTEMKA
Thermostat (Cont'd)
LC-9

Cooling Fan (Crankshaft driven)
REMOVAL AND INSTALLATION
lDo not release the drive belt tension by removing the fan/
water pump pulley.
lFan coupling cannot be disassembled and should be
replaced as a unit. If front mark
VFis present, install fan so
that side marked
VFfaces the front.
lInstall the drive belt only after the fan and fan coupling to
water pump flange bolts/nuts have been properly torqued.
lProper alignment of these components is essential. Improper
alignment will cause them to wobble and may eventually
cause the fan to separate from the water pump causing
extensive damage.
SLC227B
SLC224B
ENGINE COOLING SYSTEMKA
Radiator (Cont'd)
LC-10

INSPECTION
Check fan coupling for rough operation, wobbling, oil leakage or
bent bimetal.
After assembly, verify the fan does not wobble or flap while the
engine is running.
WARNING:
lWhen the engine is running, keep hands and clothing
away from moving parts such as drive belts and fan.
Refilling engine coolant
For details on refilling engine coolant, refer to MA section
(``Changing Engine Coolant'', ``ENGINE MAINTENANCE'').
SLC072
SLC151B
ENGINE COOLING SYSTEMKA
Cooling Fan (Crankshaft driven) (Cont'd)
LC-11

Lubrication Circuit
DLC014
ENGINE LUBRICATION SYSTEMTD
LC-12

Oil Pressure Check (On-vehicle service)
WARNING:
lBe careful not to burn yourself, as the engine and oil
may be hot.
lOil pressure check should be done in ``Neutral'' gear
position.
1. Check oil level.
2. Disconnect oil pressure switch harness connector.
3. Remove oil pressure switch.
4. Install pressure gauge and hose.
5. Start engine and warm it up to normal operating temperature.
6. Check oil pressure with engine running under no-load.
Engine speed
rpmApproximate discharge pressure
kPa (bar, kg/cm2, psi)
Idle speed More than 78 (0.78, 0.8, 11)
3,000294 - 392
(2.94 - 3.92, 3.0 - 4.0, 43 - 57)
If difference is extreme, check oil passage and oil pump for
oil leaks.
7. Install oil pressure switch with sealant.
Oil pressure switch:
:10-13Nzm (1.0 - 1.3 kg-m, 87 - 113 in-lb)
DLC013
DLC002
ENGINE LUBRICATION SYSTEMTD
LC-13