1993 DODGE TRUCK cooling

25 - 16
EMISSION
CONTROL
SYSTEMS

•

DOWNSTREAM
dciicc
HOSE
RELIEF
HOLES
J9325-37

Fig.
2 Air Injection
Pump
Operation cessive noise is fault of air injection system, discon­
nect drive belt and operate engine.
CAUTION:
Do not lubricate air injection pump. Wipe
all oil off of pump
housing.
Oil in the pump
will
cause
rapid deterioration and failure.

CAUTION:
Completely cover the air pump before

cleaning
the engine or underhood compartment. Refer to the Component Removal/Installation section
of this group for air pump replacement procedures.

CHECK
VALVE—AIR
INJECTION
TUBE
A check valve (Fig. 1) is located on each of the air
injection downstream tubes. The check valve has a one-way diaphragm which pre­
vents hot exhaust gases from backing up into the hose and pump. The check valve will protect the system if
the air injection pump belt fails, an air hose ruptures or exhaust system pressure becomes abnormally high.

TESTING
CHECK
VALVE
The check valves are not repairable. To determine
condition of valve, remove the rubber air tube from
the inlet side of each check valve. Start the engine. If
exhaust gas is escaping through the inlet side of
valve, it must be replaced.
Refer to the Component Removal/Installation section
of this group for check valve replacement procedures.

AIR
PUMP
DIAGNOSIS

Condition
Possible
Cause
Correction

EXCESSIVE
BELT
NOISE
(a)
Loose
belt
or defective auto,
belt
tensioner. (a) Refer to
Group
7,
Cooling.

(b) Seized pump. (b) Replace pump.

EXCESSIVE
PUMP
NOISE.

CHIRPING
(a) Insufficient break-in.
(a) Recheck for
noise
after
1600 km.

(1,000
miles) of operation.

EXCESSIVE
PUMP
NOISE CHIRPING,
RUMBUNG, OR KNOCKING (a) Leak in
hose.

(a) Locate
source
of leak
using
soap

solution
and correct.
(b)
Loose
hose.
(b)
Reassemble
and replace or tighten

hose
clamp.
(c)
Hose
touching other engine parts. (c) Adjust
hose
position.

(d) Relief valve inoperative. (d) Replace
relief
valve.
(e) Check valve inoperative. (e) Replace check valve.
(f)
Pump
mounting fasteners
loose.
(f) Tighten mounting
screws
as specified.

(g)
Pump
failure.
(g)
Replace pump.
NO AIR SUPPLY (ACCELERATE ENGINE TO 1500 RPM AND OBSERVE AIR
FLOW
FROM

HOSES.
IF THE
FLOW
INCREASES
AS
THE

RPM'S
INCREASE, THE
PUMP
IS
FUNCTION­
ING NORMALLY. IF NOT, CHECK POSSIBLE

CAUSE.
(a)
Loose
drive belt.
(b)
Leaks
in
supply
hose.

(c) Leak at fitting(s). (a) Refer to
Group
7,
Cooling.

(b) Locate leak and repair or replace as required.
(c) Tighten or replace
clamps.

(d) Check valve inoperative. (d) Replace check valve.
J9325-38

•

EMISSION
CONTROL SYSTEMS
25 - 17
COMPONENT REMOVAL/INSTALLATION

INDEI

page

Air
Filter/Filter
Housing—Diesel Engines
17

Air
Filter/Filter
Housing—Gas Engines
17

Air
Injection
Pump
17

Air
Injection
Pump Relief Valve
18
Check
Valve—Air
Injection
Tube
18

Coolant Temperature
Sensor
. 18
EGR
Tube—Gas Powered Engines
19

EGR
Valve
19

AIR FILTER/FILTER HOUSING-GAS ENGINES
REMOVAL/INSTALLATION Remove crankcase breather/filter hose at side of air
filter housing. Remove wingnut (Fig. 1) and remove
housing from engine. Check condition of gasket at
throttle body and replace as necessary. To replace air filter element only: Remove wingnut
and air filter housing cover (Fig. 1). Clean inside of
housing before replacing filter. Housing removal is not necessary for filter replacement.
^
WING NUT

COVER
:

GASKET
| I
MOUNTING

STUD

Fig.
1 Air
Filter
Housing—Gas
Powered
Engines—Typical
page

Electric
EGR Transducer (EET)
20

EVAP
Canister
20

EVAP
Canister Purge Solenoid
20

Fuel Tank
Filler
Tube
Cap . 21

Oxygen
(02)
Sensor
21
Powertrain Control Module (PCM)
21

Pressure
Relief/Rollover Valve
21
If housing-to-throttle body mounting stud is being
installed, tighten to 10 N»m (90 in. lbs.) torque. In­ stall housing to engine and tighten wingnut to 1.5
N»m (15 in. lbs.) torque.

AIR FILTER/FILTER HOUSING-DIESEL ENGINES
REMO
VAL/INSTALLA
TION Remove the hose clamp at air filter housing (Fig.

2).
Remove mounting nuts and remove air filter
housing from vehicle.
To replace air filter element only: Remove hose clamp
and hose at air filter housing inlet tube. Remove three
wingnuts and air filter housing cover (Figs. 2 and 3). Clean inside of housing before replacing filter. Housing
removal is not necessary for filter replacement.
When installing a new air filter element, push el­
ement into cover. Be sure it is pushed into tabs in
back of filter housing. Install wing nuts.
If housing had been removed, install mounting
nuts and tighten to 10 N»m (95 in. lbs.) torque.

AIR INJECTION PUMP
REMOVAL (1) Remove the relief valve hose clamp (Fig. 4) and
remove hose at relief valve.
(2) Remove relief valve from air pump (two bolts)
(Fig. 4). (3) Loosen (but do not remove at this time) the
three air pump pulley mounting bolts (number 2—figure 4).
(4) Relax the automatic belt tensioner and remove
the engine accessory drive belt. Refer to Group 7, Cooling System. See Belt Removal/Installation.
(5) Remove the three air pump pulley bolts and re­
move pulley from pump.
(6) Remove the two air pump mounting bolts
(number
1—figure
4) and remove pump from mount­
ing bracket.

25
- 18
EMISSION
CONTROL
SYSTEMS

Fig. 2 Air Filter Housing—Diesel Fig. 3 Air Filter Element—Diesel INSTALLATION
(1) Install air injection pump and two bolts to
mounting bracket. Tighten bolts to 40 N*m (30 ft.
lbs.) torque. (2) Install pulley and three mounting bolts.
Tighten bolts to 11 N*m (105 in. lbs.) torque.
(3) Install drive belt. Refer to Group 7, Cooling
System. See Belt Removal/Installation.
(4) Clean the gasket mounting area on the air
pump and valve. (5) Install a new gasket (Fig. 4) (relief valve-to-
pump) and install relief valve to pump. Tighten bolts to 10 N*m (95 in. lbs.) torque.
(6) Install relief valve hose and hose clamp to re­
lief valve. •

RELIEF
VALVE
J9325-39

Fig. 4 Air Injection
Pump
and
Components

AIR
INJECTION PUMP RELIEF VALVE REMOVAL

(1) Remove the relief valve hose clamp (Fig. 4) and
remove hose at relief valve.
(2) Remove relief valve from air pump (two bolts)
(Fig. 4). Discard old gasket.

INSTALLATION (1)
Clean the gasket mounting area on the pump
and valve. (2) Install a new gasket (Fig. 4) (relief valve-to-
pump) and install relief valve to pump. Tighten bolts
to 10 N*m (95 in. lbs.) torque. (3) Install relief valve hose and hose clamp to re­
lief valve.

CHECK
VALVE—AIR INJECTION TUBE REMOVAL
(1) Remove the hose clamp at inlet side of valve.
(2) Remove hose from valve.
(3) Remove valve from catalyst tube (unscrew). To
prevent damage to catalyst tube, a backup
wrench must be used on tube.

INSTALLATION
(1) Install valve to catalyst tube. Tighten to 33
N«m (25 ft. lbs.) torque.
(2) Install hose and hose clamp to valve.

COOLANT TEMPERATURE SENSOR
For description, operation, diagnosis and removal/
installation procedures, refer to Group 14, Fuel Sys­

tems.

COMPONENT AND SYSTEM INDEX

Name
Group-page

AUDIO
SYSTEMS
8F-1
SERVICE
PROCEDURES 8F-7
TEST PROCEDURES 8F-2
BATTERY/STARTER/GENERATOR SERVICE 8B-1 BATTERY SERVICE PROCEDURES 8B-1
GENERATOR SERVICE 8B-6
SPECIFICATIONS 8B-9
STARTER SERVICE PROCEDURES 8B-4
BODY COMPONENTS 23-1 CAB/BODY INTERIOR COMPONENTS
23-35

DOORS
23-21
EXTERIOR COMPONENTS 23-1
FIXED GLASS
23-29
PAINT
CODE CHART
23-54

REFINISHING PROCEDURES
23-54

BRAKES
5-1 BENDIX DISC BRAKE 5-37 BRAKE ADJUSTMENTS-BRAKE BLEEDING 5-7
BRAKE DIAGNOSIS 5-3

CHRYSLER
DISC BRAKE 5-27 DRUM BRAKES—ELEVEN INCH 5-46
DRUM BRAKES-TWELVE INCH 5-50
GENERAL INFORMATION 5-1 MASTER CYLINDER—COMBINATION VALVE-BRAKE
LINES 5-10
PARKING BRAKES 5-56
POWER BRAKE BOOSTER-BRAKE PEDAL 5-20 POWER BRAKE VACUUM PUMP-DIESEL ENGINE. . 5-22

REAR
WHEEL ANTILOCK
(RWAL)
BRAKES 5-59
SPECIFICATIONS 5-65
CHIME/BUZZER WARNING
SYSTEMS
8U-1
CLUTCH 6-1 CLUTCH DIAGNOSIS 6-2 CLUTCH SERVICE 6-11
COOLING SYSTEM 7-1
DIAGNOSIS 7-4
ENGINE ACCESSORY DRIVE BELTS 7-40
ENGINE BLOCK HEATERS 7-48

SERVICE
PROCEDURES 7-15 SPECIFICATIONS 7-49
ELECTRICAL 8A-1 BATTERY TEST PROCEDURES 8A-2
ENGINE STARTER MOTOR TEST PROCEDURES.... 8A-9
GENERAL INFORMATION 8A-1
GENERATOR TEST PROCEDURES ON VEHICLE . . . 8A-13
GROUP INDEX 8A-1
SPECIFICATIONS 8A-18
BATTERY/STARTING/CHARGING
SYSTEMS
DIAGNOSTICS 8A-1

EMISSION
CONTROL
SYSTEMS.
25-1 AIR INJECTION SYSTEM—5.9L HDC-GAS ENGINE . 25-15 COMPONENT REMOVAL/INSTALLATION 25-17 EVAPORATIVE EMISSION CONTROLS 25-6
EXHAUST EMISSION CONTROLS 25-10
GENERAL INFORMATION 25-1
ENGINES 9-1 3.9L ENGINE SERVICE PROCEDURES 9-17 5.2L ENGINE SERVICE PROCEDURES 9-47
5.9L (DIESEL) ENGINE SERVICE PROCEDURES . . . 9-107
Name
Group-page

5.9L ENGINE SERVICE PROCEDURES 9-77 ENGINE DIAGNOSIS 9-5
STANDARD SERVICE PROCEDURES 9-1
EXHAUST SYSTEM AND INTAKE MANIFOLD 11-1
EXHAUST SYSTEM DIAGNOSIS 11-3
GENERAL INFORMATION 11-1

SERVICE
PROCEDURES (DIESEL ENGINES) 11-17

SERVICE
PROCEDURES (GASOLINE ENGINES) 11-4
SPECIFICATIONS 11-27
FRAME AND BUMPERS 13-1 ATTACHED COMPONENTS 13-30
BUMPERS
13-1
FRAME 13-20
SNOW PLOW 13-3
FRONT SUSPENSION AND AXLE 2-1 FRONT SUSPENSION—2WD VEHICLES 2-7
FRONT SUSPENSION—4WD VEHICLES 2-14 FRONT WHEEL ALIGNMENT 2-3
GENERAL INFORMATION 2-1 MODEL 44 FRONT AXLE 2-17
MODEL 60 FRONT AXLE 2-49
TORQUE SPECIFICATIONS 2-75
FUEL SYSTEM 14-1 ACCELERATOR PEDAL AND THROTTLE CABLE . . . 14-25
DIESEL
FUEL INJECTION—COMPONENT DESCRIPTION/SYSTEM OPERATION 14-76

DIESEL
FUEL INJECTION-GENERAL DIAGNOSIS. . 14-88

DIESEL
FUEL INJECTION-SERVICE
PROCEDURES
14-106

FUEL DELIVERY SYSTEM-EXCEPT DIESEL 14-3
FUEL DELIVERY-DIESEL ENGINE 14-15 FUEL TANKS 14-20
GENERAL INFORMATION 14-1 MULTI-PORT FUEL INJECTION (MPI)-COMPONENT DESCRIPTION/SYSTEM OPERATION-EXCEPT
DIESEL
14-29
MULTI-PORT FUEL INJECTION
(MPlj-COMPONENT
REMOVAL/INSTALLATION-EXCEPT DIESEL .... 14-64
MULTI-PORT FUEL INJECTION (MPI)—GENERAL DIAGNOSIS-EXCEPT DIESEL 14-43

SERVICE
ADJUSTMENTS-DIESEL
14-122
SPECIFICATIONS
14-123

HEATING AND AIR CONDITIONING 24-1 CLIMATE CONTROL SYSTEM
24-29

COMPRESSOR
SERVICE
(SD-709)
24-21 DIAGNOSTIC PROCEDURES 24-3
GENERAL INFORMATION 24-1 REFRIGERANT SYSTEM SERVICE PROCEDURES . . 24-17
TORQUE SPECIFICATIONS
24-39

HORNS 8G-1
SERVICE
PROCEDURES 8G-3
TEST PROCEDURES 8G-1

IGNITION
SYSTEMS
8D-1 COMPONENT IDENTIFICATION/SYSTEM OPERATION. 8D-1
COMPONENT REMOVAL/INSTALLATION 8D-18 DIAGNOSTICS/SERVICE PROCEDURES 8D-7
IGNITION
SWITCH
8D-25

SPECIFICATIONS
8D-28

INSTRUMENT PANEL AND GAUGES 8E-1