oil level DODGE TRUCK 1993 Service Manual Online

24
- 20
HEATING
AND AIR
CONDITIONING

• (3) Turn
3
refrigerant manifold valves completely
clockwise
to
puncture
the
cans
and
close
the
mani­
fold valves.
(4) Purge
the air
from
the
charging line
by
loosen­
ing
the
charging hose
at the
manifold gauge
set and

turn
one of the
refrigerant valves counterclockwise. When
the
refrigerant
gas
starts escaping from
the

loose connection, tighten
the
hose.
(5) Fully open
all 3
refrigerant manifold valves
and place
the
cans
of
refrigerant into
a pan
contain­
ing 52°C (125°F) water.
The
water will warm
the

charging
can and aid in the
transfer
of the
charge
into
the
system.
(6) Start
the
engine
and
move
the
controls
to A/C

low blower position.
The electronic temperature cycling switch will pre­
vent
the
clutch from engaging until refrigerant
is
added
to the
system.
If the
clutch does engage,
re­

place
the
switch before proceeding
any
further. (7) Charge through
the
suction side
of the
system
by slowly opening
the
suction manifold valve. Adjust
the valve
as
necessary
so
charging pressure does
not
exceed
345
kPag
(50
psig). Maintain
the
temperature
of
the
water
in the pan by
adding warm water
as

necessary. (8) Adjust
the
engine speed
to a
fast idle
of
approx­
imately
1,300 RPM.
(9) When
all 3
cans
of
refrigerant
are
completely
empty, close
the
manifold gauge
set
valves
and re­

frigerant manifold valves. The maximum refrigerant charge
is 44 oz.

REFRIGERANT
LEAK REPAIR PROCEDURE

LOST CHARGE If
the
system
has
lost
all
charge
due to a
leak: (1) Evacuate
the
system.
(2) Charge
the
system with approximately
1
pound
of refrigerant. (3) Locate
all
leaks.
(4) Repair
all
leaks.
(5) Replace filter-drier bottle.

CAUTION:
Replacement
filter-drier
units
must
be

sealed
while
in
storage.
The
drier
used
in
these

units
absorbs
and
traps
moisture
quickly
upon
ex­

posure
to the
atmosphere.
When
installing
a
drier,

have
all
tools
and
supplies ready
for
quick
reas­

sembly
to
avoid keeping
the
system open
any
longer
than
necessary.

(6) Check system
oil
level. (7) Evacuate
and
charge
the
system.
LOW CHARGE If
the
system
has not
lost
all of its
refrigerant
charge; locate
and
repair
all
leaks.
If it is
necessary
to increase
the
system pressure
to
find
the
leak
(be­
cause
of an
especially
low
charge),
add 230 g (1/2 lb)

of refrigerant.
If
there
has
been
a
significant
oil
loss,
check
the
system
oil
level.
If
leak repair
was
possible
without discharging system
and an oil
level check
was
not
necessary,
use
procedure
for
correcting
low

refrigerant level.

CORRECTING
LOW
REFRIGERANT LEVEL
Since
the
refrigeration system
is
completely sealed,
the refrigerant level will
not be low
unless there
is a
leak
in the
system. Before adding refrigerant where
the
cause
of a low

level
is not
known,
the
system should
be
tested
for

leaks.
Assuming that leaks have been corrected without
discharging
the
system, proceed with partial charge.
Install
and
connect manifold gauge
set.
(1) Close both manifold gauge
set
valves. Open
manifold gauge
set
needle valve.
(2) Connect
the
suction gauge test hose
to the
suc­
tion service port
of the
compressor. Connect
the
dis­ charge gauge test hose
to the
discharge service port. (3) Connect
an end of
long test hose
to the
center
manifold outlet,
and
other
end to
refrigerant dispens­ ing manifold. (4) Close
the 2
dispensing manifold valves
and

open remaining dispensing manifold valve. Remove
protective
cap
from opened valve.

WARNING: NEVER
USE
THESE CANS
TO
CHARGE
INTO
THE
HIGH
PRESSURE SIDE
OF
THE
SYSTEM

(COMPRESSOR
DISCHARGE
PORT)
OR
INTO
A
SYSTEM
THAT
IS AT
HIGH
TEMPERATURE.
THE
HIGH
SYSTEM PRESSURES COULD
BE
TRANS­
FERRED
INTO
THE
CHARGING
CAN
CAUSING
IT

TO EXPLODE.

(5) Screw
a can of R-12 to the
opened manifold
valve.
Be
sure gasket
is in
place
and in
good condi­
tion. Tighten refrigerant
can and
manifold locking nut
to
ensure
a
good seal.
Do not
overtighten.
Tighten
to 9.5 N*m (7 ft. lbs.)
torque,
if
gasket
is in
good condition.
(6) Turn manifold valve (above
the
refrigerant
can)

completely clockwise
to
puncture
the can.
This closes
the valve
and
seals
the
refrigerant
in the can.

CAUTION:
Do not
heat refrigerant
12
above
52°C

(125°F).

(7) Place refrigerant
can in a
large
pan of
water
heated
to
52°C (125°F). Place
pan of
water containing
the refrigerant
can on an
accurate scale
so the
amount
of
refrigerant added
can be
weighed. Open
the refrigerant manifold valve.
(8) Purge
all air
from test hoses.
Air in the
system
will
be
trapped
in the
condenser causing abnormally
high discharge pressures
and
interfering with con­ densing
of the
refrigerant.

•

HEATING
AND AIR
CONDITIONING
24 - 21 (a) Loosen both test hoses at the manifold gauge
set. Tighten the hoses as soon as the air is purged. (b) Loosen charging hose connection at manifold
gauge set. This will purge air from the charging

hose.
Tighten connection as soon as air is purged.
(9) With vehicle windows open and hood up, oper­
ate engine at 1,300 RPM. (10) Place air conditioner control on A/C and place
the fan switch on high. (11) If necessary, block the condenser to maintain
a discharge pressure of 1 550-1 725 kPag (225-250

psig).
System must be charged through the evapora­
tor suction service ports as follows:
(a) Slowly open the suction service gauge valve.
Meter flow of refrigerant by adjusting the suction service gauge valve so the pressure registered at
the suction service gauge does not exceed 345 kPag

COMPRESSOR
J
(50
psig). Keep refrigerant container upright.
(b) Add refrigerant gas until there is no foam visi­
ble at the sight glass. As soon as all foam clears, note the weight registered on the refrigerant scale.
(c) Watch the refrigerant weighing scale and add
437 g (14 oz.) of refrigerant (equivalent to 1 can).
(d) Close the suction gauge valve.

CAUTION:
TOO
much
refrigerant
in the
system
can

cause
abnormally high discharge pressures. Care
must
be
used
so the
exact recommended amount
of
refrigerant
is
added
after
foam clears
in the
sight

glass.

(e) Close dispensing manifold valve. Remove test
hoses and adapters from the service ports of com­
pressor and install protective caps at service ports.

RVICE (SD-709)

INDEX

page

Compressor
21

Compressor
Shaft Seal
.................... 25
The A/C system uses a 7 piston design Sanden SD-
709 compressor. Designated the SD-709, the compres­
sor is mounted on the front right side of the engine
and is driven by a serpentine belt.
System lubrication is provided by 135cc ±15cc (4.6
cu. in. ±0.5 cu. in.) of 500 viscosity refrigerant oil.
The clutch used on the compressor consists of 3 ba­
sic components:
(1) The pulley.
(2) The front plate. (3) The field coil.
The pulley and field coil are attached to the front
head of the compressor with snap rings. The hub is keyed to the compressor shaft and is retained on the
shaft with a self-locking nut. Special service tools are
required to remove and install the clutch plate on
the compressor shaft.

COMPRESSOR
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Disconnect the clutch lead wire.
(3) Remove the discharge and inlet (suction) ser­
vice valves from the compressor. Plug or tape all the
openings.
(4) Refer to Group 7, Cooling System and remove
the drive belt(s). (5) Remove the bolts and lift the compressor from
the mounting bracket (Fig. 1).
page

Cylinder Head
/
Valve Plate
27
Magnetic
Clutch
22

Fig.
1
Compressor
Mounting

INSTALLATION
If a replacement compressor is being installed,
check the oil level. Add or subtract oil as necessary.
Install the magnetic clutch on the compressor.
(1) Install the compressor on the mounting bracket.
Tighten the bolts to 27 N*m (20 ft. lbs.) torque.
(2) Refer to Group 7, Cooling System and install
the drive belt(s).
(3) Check the belt tension.
@ New drive belt-800-900 N (180-200 lbs-f).
• Used belt-623-712 N (140-160 lbs-f).

HEATING
AND
AIR
CONDITIONING
24 - 29
CLIMATE CONTROL
SYSTEM

INDEX

page

Air Conditioner Distribution
and
Spot Cooler
Ducts-Center
. . 38

Air Conditioner Distribution
and
Spot Cooler
Ducts-Left Bi-Level
38

Air Conditioner Distribution
and
Spot Cooler

Ducts-Right
Bi-Level
38

Air
Outlet
Assemblies Right
Side
.............
38

Control Test
......
30
Defroster Duct
34

Electrical Controls
and
Circuits
30
Electronic Temperature Cycling Switch
37

Evaporator Control Unit
. . 34

GENERAL
INFORMATION
This
air
conditioner
is
designed specifically
for
con­
ventional
cab
trucks with
the
heater-evaporator
package designed
to fit
under
the
instrument panel.
The system
is
manually controlled
by the
operator. Controls have been kept simple
for
ease
of
service and operation. In
the
blend
air
reheat
air
conditioning unit,
all

the
air
entering
the
system passes through
the
evap­ orator.
A
selected portion passes through
the
heater
core depending
on the
position
of the
blend
air
door.
The system controls
are
located
in the
center
of the
instrument panel within easy reach
of the
driver.
The combination electrical
and
vacuum switch con­
trols
the
compressor clutch, mode
of
operation
and

blower. Modes
are Off, Max. A/C, A/C,
Vent, Heat and Defrost.
A
4-speed blower motor switch controls
the amount
of air
flow.
The
evaporator-heater pack­ age includes:
•
The
blower motor. • Intake duct with outside
air
recirculating door.
• Evaporator coil
• Heater core.
• Defroster discharge doors.
• Blower motor speed resistors.
• Vacuum harness.
• Vacuum actuators.
•
A/C air
outlets
to the
distribution ducts. Defrost, Heat,
A/C and
Vent modes automatically
supply
100%
outside
air.
The
air
distribution ducts supply
air
from
the
unit
to
4
panel mounted, fully directional, outlets.
The
faceplate
has 2
outlets
and 2 are
snapped into
the

panel
on the
right side. Satisfactory performance
of the air
conditioning
and heating system
is
dependent upon correct opera­
tion
and
adjustment
of all
operating controls.
The in­
spections, tests
and
adjustments should
be
used
to

locate
the
cause
of a
malfunction.
The
tests
in
this
page

Evaporator Heater Assembly
36

Expansion
(H)
Valve
37

Faceplate
32

General Information
. 29

Heater Assembly
. 33

Heater Control
32

Louver
Assemblies
39

Operation
of All
Controls
29
Resistor
Block
33

Temperature
and
Mode Control Cables
. 32
Vacuum
Actuators
36
Vacuum
Controls
and
Circuits
30

manual have been arranged
in a
logical sequence
that
has
proved
to be the
surest
and
shortest route
to
accurate diagnosis.
It is
recommended that they
be

followed
and
performed
in the
order they
are
pre­ sented.

OPERATION
OF ALL
CONTROLS
Operation must
be
tested
as
described
in the
fol­
lowing sequence: (1) Inspect, test,
and
adjust compressor drive belt.
(2) Start engine
and
adjust engine speed
to 1,300

RPM.
Use a
reliable tachometer. (3) Move temperature control lever
to
Cool position
and mode lever
to A/C
position. (4)
The
inlet
air
door should
be
open
to
outside
air.

Open vehicle windows. (5) Test
the
blower operation
at all 4
speed posi­

tions.
If the
blower does
not
operate correctly refer
to

Electrical Controls
and
Circuit. Leave
the
blower switch
in the
HIGH position.
(6)
The
compressor should
be
running
and the air

conditioning system
in
operation. In addition
to the six
position push button selector,
the
A/C
Heater control consists
of:
TEMPERATURE LEVER-Controls
the
tempera-.
ture
of the
discharge
air in all
modes except
MAX

A/C
and Off
when
the
vacuum operated water valve is closed. Moving
the
lever
to the
left provides cooler
air
and
moving
it to the
right provides warmer
air.
BLOWER SWITCH-The system blower
can be op­

erated
at 4
speeds.
•
LOW at the
bottom. • MEDIUM
1 at the
lower center.
• MEDIUM
2 at the
upper center.
• HIGH
at the top
switch position. The blower will
be on and
operating
at the
speed
selected,
in all
push button positions except
Off.
AIR DIRECTIONAL VANES-Air
is
delivered
through
4
panel outlets.
The 4
outlets
are
adjustable