cooling NISSAN PICK-UP 1998 Owner's Manual

Trouble Diagnoses for Abnormal Pressure
Whenever system's high or low-pressure side is abnormal, diagnose using a manifold gauge. The marker
above the gauge scale in the following table indicates the standard (normal) pressure range. Since the
standard (normal) pressure differs from vehicle to vehicle, refer to HA-26 (``Ambient air temperature-to-op-
erating pressure table'').
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high and low-pressure
sides are too high.
AC359A
lPressure is reduced soon
after water is splashed on
condenser.Excessive refrigerant charge in
refrigeration cycle.Reduce refrigerant until speci-
fied pressure is obtained.
Air suction by cooling fan is
insufficient.Insufficient condenser cooling
performance.
¯
V1Condenser fins are
clogged.
V2Improper fan rotation of
cooling fan.
lClean condenser.
lCheck and repair cooling fan
as necessary.
lLow-pressure pipe is not
cold.
lWhen compressor is stopped
high-pressure value quickly
drops by approximately 196
kPa (2.0 bar, 2 kg/cm
2,28
psi). It then decreases gradu-
ally thereafter.Poor heat exchange in con-
denser.
(After compressor operation
stops, high pressure decreases
too slowly.)
¯
Air in refrigeration cycle.Evacuate repeatedly and
recharge system.
Engine tends to overheat. Engine cooling systems mal-
function.Check and repair each engine
cooling system.
lAn area of the low-pressure
pipe is colder than areas
near the evaporator outlet.
lPlates are sometimes cov-
ered with frost.
lExcessive liquid refrigerant
on low-pressure side.
lExcessive refrigerant dis-
charge flow.
lExpansion valve is open a
little compared with the speci-
fication.
¯
V1Improper thermal valve
installation.
V2Improper expansion valve
adjustment.Replace expansion valve.
High-pressure side is too high
and low-pressure side is too
low.
AC360A
Upper side of condenser and
high-pressure side are hot,
however, liquid tank is not so
hot.High-pressure tube or parts
located between compressor
and condenser are clogged or
crushed.lCheck and repair or replace
malfunctioning parts.
lCheck lubricant for contami-
nation.
TROUBLE DIAGNOSES
HA-27

Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side sometimes
becomes negative.
AC354A
lAir conditioner system does
not function and does not
cyclically cool the compart-
ment air.
lThe system constantly func-
tions for a certain period of
time after compressor is
stopped and restarted.Refrigerant does not discharge
cyclically.
¯
Moisture is frozen at expansion
valve outlet and inlet.
¯
Water is mixed with refrigerant.
lDrain water from refrigerant
or replace refrigerant.
lReplace liquid tank.
Low-pressure side becomes
negative.
AC362A
Liquid tank or front/rear side of
expansion valve's pipe is
frosted or dewed.High-pressure side is closed
and refrigerant does not flow.
¯
Expansion valve or liquid tank
is frosted.Leave the system at rest. Start
it again to check whether or not
the problem is caused by water
or foreign particles.
lIf water is the cause, initially
cooling is okay. Then the
water freezes, causing a
blockage. Drain water from
refrigerant or replace refriger-
ant.
lIf due to foreign particles,
remove expansion valve and
remove the particles with dry
and compressed air.
lIf either of the above meth-
ods cannot correct the
problem, replace expansion
valve.
lReplace liquid tank.
lCheck lubricant for contami-
nation.
TROUBLE DIAGNOSES
Trouble Diagnoses for Abnormal Pressure
(Cont'd)
HA-29

A/C RELAY
Check continuity between terminal Nos.V3andV5.
Conditions Continuity
12V direct current supply between terminal Nos.
V1andV2Yes
No current supply No
If NG, replace relay.
TRIPLE-PRESSURE SWITCH
TerminalsHigh-pressure side line
pressure
kPa (bar, kg/cm2, psi)Operation Continuity
Low-pres-
sure side
V1-V4
Increasing to
152.0 - 201.0
(1.520 - 2.010,
1.55 - 2.05, 22.0 - 29.2)ON Exists.
Decreasing to
152.0 - 201.0
(1.520 - 2.010,
1.55 - 2.05, 22.0 - 29.2)OFFDoes not
exist.
Medium-
pressure
side*
V2-V3
Increasing to
1,422 - 1,618
(14.22 - 16.18,
14.5 - 16.5, 206 - 235)ON Exists.
Decreasing to
1,128 - 1,422
(11.28 - 14.22,
11.5 - 14.5, 164 - 206)OFFDoes not
exist.
High-pres-
sure side
V1-V4
Decreasing to
2,059 - 2,256
(20.6 - 22.6,
21 - 23, 299 - 327)ON Exists.
Increasing to
2,648 - 2,844
(26.5 - 28.4,
27 - 29, 384 - 412)OFFDoes not
exist.
* For cooling fan motor operation
THERMO CONTROL AMP.
Evaporator outlet air temperature
ÉC (ÉF)Thermo amp.
operationTester
Decreasing to 0.1 - 0.9 (32 - 34) Turn OFF Approx. 12V
Increasing to 2.5 - 3.5 (37 - 38) Turn ON Approx. 0V
SEF090M
RHA364G
RHA365G
TROUBLE DIAGNOSES
Electrical Components Inspection (Cont'd)
HA-44

Maintenance of Lubricant Quantity in
Compressor
The lubricant used to lubricate the compressor circulates through
the system with the refrigerant. Add lubricant to compressor
when replacing any component or after a large gas leakage
occurred. It is important to maintain the specified amount.
If lubricant quantity is not maintained properly, the following mal-
functions may result:
lLack of lubricant: May lead to a seized compressor
lExcessive lubricant: Inadequate cooling (thermal exchange
interference)
LUBRICANT
Name: Nissan A/C System Oil Type R
Part number: KLH00-PAGR0
CHECKING AND ADJUSTING
Adjust the lubricant quantity according to the flowchart shown
below.
START
Can lubricant return operation be per-
formed?
lA/C system works properly.lThere is no evidence of a large amount of
lubricant leakage.
No
cYes
Perform lubricant return operation, proceeding as follows:
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1. Start engine, and set the following conditions:
lTest condition
Engine speed: Idling to 1,200 rpm
A/C or AUTO switch: ON
Blower speed: Max. position
Temp. control: Optional [Set so that intake air temperature is
25 to 30ÉC (77 to 86ÉF).]
2. Next item is for V-5 or V-6 compressor. Connect the manifold
gauge, and check that the high pressure side pressure is 588 kPa
(5.9 bar, 6 kg/cm
2, 85 psi) or higher.
If less than the reference level, attach a cover to the front face of
the condenser to raise the pressure.
3. Perform lubricant return operation for about 10 minutes.
4. Stop engine.
CAUTION:
If excessive lubricant leakage is noted, do not perform the lubricant
return operation.
Should the compressor be replaced?
No Yes
b
VA(Go to next page.)
Is there any part to be replaced?
(Evaporator, condenser, liquid tank or in
case there is evidence of a large amount of
lubricant leakage.)
No
cYes
After replacing any of the following major components, add the correct
amount of lubricant to the system.
Amount of lubricant to be added
*1: If compressor is replaced, addition of lubricant is included in the flow
chart.
*2: If refrigerant leak is small, no addition of lubricant is needed.
Carry out the A/C performance test.b
Part replacedLubricant to be added to sys-
tem
Remarks
Amount of lubricant
m!(Imp fl oz)
Evaporator 75 (2.6) Ð
Condenser 75 (2.6) Ð
Liquid tank 5 (0.2)Add if compressor is not
replaced. *1
In case of refrigerant leak30 (1.1) Large leak
Ð Small leak*2
.
.
.
.
.
SERVICE PROCEDURES
HA-50

3. Move probe along component approximately 25 to 50 mm
(1 to 2 in)/sec.
CHECKING PROCEDURE
To prevent inaccurate or false readings, make sure there is
no refrigerant vapor or tobacco smoke in the vicinity of the
vehicle. Perform the leak test in calm area (low air/wind
movement) so that the leaking refrigerant is not dispersed.
1. Turn engine off.
2. Connect a suitable A/C manifold gauge set to the A/C ser-
vice ports.
3. Check if the A/C refrigerant pressure is at least 345 kPa
(3.452 bar, 3.52 kg/cm
2, 50 psi) above 16ÉC (61ÉF). If less
than specification, evacuate and recharge the system with
the specified amount of refrigerant.
NOTE: At temperatures below 16ÉC (61ÉF), leaks may not be
detected since the system may not reach 345 kPa
(3.452 bar, 3.52 kg/cm
2, 50 psi).
4. Conduct the leak test from the high side to the low side at
points
VathroughVn. Refer to HA-52.
Perform a leak check for the following areas carefully. Clean
the component to be checked and move the leak detector
probe completely around the connection/component.
lCompressor
Check the fitting of high and low pressure hoses, relief valve
and shaft seal.
lLiquid tank
Check the pressure switch, tube fitting, weld seams and the
fusible plug mounts.
lService valves
Check all around the service valves. Ensure service valve
caps are secured on the service valves (to prevent leaks).
NOTE: After removing A/C manifold gauge set from service
valves, wipe any residue from valves to prevent any
false readings by leak detector.
lCooling unit (Evaporator)
Turn blower fan on ``High'' for at least 15 seconds to dissi-
pate any refrigerant trace in the cooling unit. Insert the leak
detector probe into the drain hose immediately after stopping
the engine. (Keep the probe inserted for at least ten sec-
onds.)
5. If a leak detector detects a leak, verify at least once by
blowing compressed air into area of suspected leak, then
repeat check.
6. Do not stop when one leak is found. Continue to check for
additional leaks at all system components.
7. Start engine.
SHA708EA
SERVICE PROCEDURES
Checking Refrigerant Leaks (Cont'd)
HA-57

ENGINE LUBRICATION &
COOLING SYSTEMS
SECTION
LC
CONTENTS
PRECAUTIONS AND PREPARATION..................... 1
Liquid Gasket Application Procedure .................... 1
Special Service Tools ............................................ 2
KA
ENGINE LUBRICATION SYSTEM............................ 3
Lubrication Circuit .................................................. 3
Oil Pressure Check ................................................ 4
Oil Pump ................................................................ 4
ENGINE COOLING SYSTEM.................................... 6
Cooling Circuit........................................................ 6
System Check ........................................................ 6
Water Pump ........................................................... 7
Thermostat ............................................................. 8
Radiator.................................................................. 9
Cooling Fan (Crankshaft driven).......................... 10
TD
ENGINE LUBRICATION SYSTEM.......................... 12
Lubrication Circuit ................................................ 12
Oil Pressure Check (On-vehicle service) ............ 13
Oil Pump .............................................................. 14
Oil Filter Bracket .................................................. 16
Oil Cooler ............................................................. 17Oil Jet ................................................................... 18
ENGINE COOLING SYSTEM.................................. 19
Cooling Circuit...................................................... 19
Cooling System Inspection .................................. 20
Water Pump and Cooling Fan (Camshaft
driven) .................................................................. 21
Thermostat ........................................................... 23
Radiator................................................................ 24
Refilling Engine Coolant ...................................... 24
ENGINE ROOM FAN MOTOR ELECTRICAL
CIRCUIT................................................................... 25
Wiring Diagram .................................................... 25
Cooling Fan (Motor driven) .................................. 26
Electrical Components Inspection ....................... 26
ENGINE COOLING SYSTEM.................................. 28
Radiator (Aluminum type) .................................... 28
Overheating Cause Analysis ............................... 31
SERVICE DATA AND SPECIFICATIONS (SDS)... 32
Engine Lubrication System (KA).......................... 32
Engine Cooling System (KA) ............................... 32
Engine Lubrication System (TD).......................... 32
Engine Cooling System (TD) ............................... 32
LC

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