Air Conditioning //—->> "^^Izz^^ • ^ ^
General System Procedures L ^—/ ' —^ ^./^
Adding Refrigerant
In order that the air conditioning system may operate efficiently it must contain a full refrigerant charge. The
indications of some system defects, and the results of certain tests, shows that
a
low charge
is
the most probable cause
of the fault. In such cases the charge shou
Id
be recovered from the
system,
the weight noted, and the correct amount
installed.
Note: Never attempt to
guess the
amount of refrigerant in
a
system.
Always recover and
recharge
with
the
correct
charge
weight,
this is the only
accurate
method.
Caution: If oil is drawn out during the recovery
process,
the correct amount can be added directly from your
recovery-recycle-
recharge station
(if so
equipped)
prior to the charging
process.
It must be
stressed
that the need to protect
compressor
oil from
moisture is vital, observe
the procedures
in Handling Lubricating Oil.
Warning: Liquid refrigerant boils at -29°C (-20°F) at atmospheric pressure. Serious injury, even blindness, can occur if
the refrigerant comes into contact with the eyes.
Goggles and gloves must be warn while working with refrigerant.
First Aid
If refrigerant should contact the eyes or
skin,
bathe the eyes or affected area with cold water for several minutes. Do
not rub. As soon as possible thereafter, obtain treatment from a doctor or eye specialist.
8-14 May 1996
Air Conditioning
Refrigeration /s:s^°27
Refrigeration
Safety Precautions
The air conditioning system is designed to use only
Refrigerant E134A (dichlorodifluoromethane). Extreme
care must betaken NOT to use
a
methylchloride refrigerant.
The chemical reaction between methylchloride and the
aluminium parts ofthe compressor results in the formation
ofproductswhich burn spontaneously on exposure toair,
or decompose with violence in the presence of moisture.
The suitable refrigerant is supplied under the following
names.
El 34A KLEA or equivalent
Warning: Take care when handling refrigerant. Serious
damage will occur if it is allowed to come into
contact with the eyes. Always wear with goggles
and gloves when working with refrigerant
First Aid
If refrigerant should come into contact with the
eyes or
skin,
splash the eyes or affected area with
cold water for several minutes. DO NOT RUB. As
soon as possible thereafter, obtain treatment from a
Doctor or an eye specialist.
Good Practice
1.
Protective sealing plugs must be fitted to all
disconnected pipes and units.
2.
Theprotectivesealingpiugsmustremain inposition
on ail replacement components and pipes until
immediately before assembly.
3. Any part arriving for assembly without sealing
plugs in position must be returned to the supplier as
defective.
4.
It is essential that a second backing spanner is
always used when tightening or loosening all joints.
This minimises distortion or strain on components
or connecting hoses.
5. Components must not be lifted by connecting
pipes,
hoses or capillary tubes.
6. Care must be taken not to damage fins on the
condenser or evaporator matrices. Any damage
must be rectified by the use of fin combs.
7. Before assembly oftube and hosejoints, use
a
small
amount of clean new refrigerant oil on the sealing
seat.
8. Refrigerant oil for any purpose must be kept very
clean and capped at all times. This prevents the oil
absorbing moisture.
9. Before assembly the condition of joints and flares
must be examined. Dirt and even minor damage
will cause leaks at the high pressure points
encountered in the system.
10.
Dirty end fitting can only be cleaned using a cloth
wetted with alcohol.
11.
Afterremovingsealingplugsand immediatelybefore
assembly, visually check the bore of pipes and
components. Where any dirt or moisture is
discovered,
the part must be rejected.
12. Ail components must be allowed to reach room
temperature before sealing plugs are removed.
This prevents condensation should the component
be cold initially.
13.
Before finally tightening hose connections ensure
that the hose lies in the correct position, is not
kinked or twisted and will not be trapped by
subsequent operations, e.g., refitting or closing
bonnet.
14.
Check that hoses are correctly fitted in clips or
straps.
15.
The compressor must be stored horizontally with
the sump down. It must not be rotated before fitting
and charging. Do not remove the shipping plate
until immediately before assembly. Always use
new "O" ring seals in those joints that incorporate
them.
"O" ring seals should be coated with
compressor oil before fitting.
16.
Components or hoses removed must be sealed
immediately after removal.
1 7. Afterthe system has been opened the receiver-drier
must be renewed.
18.
Before
testing,
run the engine until normal running
temperature is reached. This ensures that sufficient
vacuum is available for test. For cooling tests the
engine must be running for the compressor clutch
to operate.
8-34 May 1996
^=2?
Air Conditioning
System Checking with the Manifold Gauge Set
System Checking with the Manifold
Gauge Set
Connecting the Manifold Gauge Set
Caution: Only use hoses with connectors which are
dedicated to HFC 134A charge ports.
Attachmentofthehosequick release connectors to
the high and low side
system
ports
is
straightforward,
provided that the high and low valves are closed
and the system is NOT operational.
Assessment ofthe system's operating system can be
carried out by using the facilities ofthe Recovery-
Recharging-Recycling station. Follow the
manufacturer's instructions carefully and closely
observe the safety procedures.
Warning: Under no circumstances should the connections
be made with the
system
in operation or the
valves
open. Should the valves be open and a vacuum
pump or refrigerant container attached, an
explosion could occur
as
a result of high pressure
refrigerant being forced back into the vacuum
pump or container.
Stabilising the System
Accurate test gauge data can be attained only if the
system temperatures and pressures are stabilised.
Ensure that equipment and its hoses cannot come
into contact with moving parts or heat sources.
It is recommended that a free standing air mover is
placed in front of the vehicle to provide mass air
flow through the condenser-cooling system.
Checking Procedure
Connecting the Gauge Set.
A test hose connected to the fitting directly under
the low side gauge is used to connect the low side
ofthe test manifold into the low side ofthe system,
and a similar connection is found on the high side.
When connecting the gauge manifold set to the air
cond ition i ng system an access va Ive core removi ng
tool is available for connecting the test hoses to the
high and low sides ofthe system.
Using the valve removing tool it enables the valve
core to be removed and held back inside the tool
eliminating restrictions and, thereby, providing a
full flow of refrigerant.
Warning: Do not open the high side hand valve while the
air conditioning system is in operation because,
high pressure refrigerant will be forced through
the high side gauge and to the refrigerant container,
if it is attached.
This
could cause the container to
rupture or the fitting at the safety container valve
to burst resulting in damage and personal injury.
1.
With theengineswitched off, remove the protective
caps from the schraeder valves.
2.
Fit the access valve removal tool to the schraeder
valves. Ensure that both the manifold hand valves
are in the closed position.
3. Connect the high pressure manifold gauge hose (to
the high pressure side of the air conditioning side of
the system (high side is always the line from the
compressor to the condenser). Connect the low
pressure or compound gauge hose to the low
pressure side ofthe air conditioning system.
4.
Using the access valve removal tool loosen and
screw out the valve cores.
1.
Start the engine and allow it to attain normal
working temperature then set it at fast idle (typically
1200 to ISOOrpm).
2.
Select full air conditioning performance.
3. With all temperatures and pressures stable or
displaying symptoms of faults, begin relevant test
procedures.
May 1996 8-39
^?
Air Conditioning
Torque Settings / Depressurising the System
Torque Levels for the Hose Connections
COMPONENT TORQUE Nm
Evaporator Hose
Hose to Expansion Valve 32.0 ± 4.0
Hose to Compressor 34.0 ± 2.0
Condenser Hose
Hose to Compressor 34.0 ± 2.0
Hose to Compressor 25.0 ± 4.0
Condenser Pipe
Pipe to Drier Bottle 6.0 ± 1.5
Evaporator Pipe
Pipe to Expansion Valve 16.0 ± 1.5
Air Conditioning Procedures
Depressurising
Note:
Observe
all
safety
precautions and do not smoke
while carrying out the following
procedures.
1.
With the engine switched off, remove the protective
caps from the schraeder valves.
2.
Ensure the manifold gauge set hand valves are in
the closed position, then by using the access valve
core remover connect the manifold gauge set to the
system with the red hose to the high pressure side
and the blue hose to the low pressure side.
3. Screw out the valve core to allow the refrigerant to
flow.
4.
Place the centre hose of the manifold set into a
suitable container.
5. Slowly open the high or low side manifold hand
valve and adjust the valve for a smooth refrigerant
flow. Watch the refrigerant for any signsof escaping
oil and adjust the hand valve to prevent any oil
escaping.
6. If oil islostduringthedischarge,thecompressoroil
level must be checked and if necessary topped up.
7. As the discharge rate slows down, open the other
manifold hand valve so that refrigerant flows from
both high and low pressure sides of the system.
8. Constantly adjust the hand valves to ensure that oil
does not flow. When a zero reading is shown on
both high and low pressure gauges the system is
discharged.
8. Close both manifold hand valves.
Recovering Refrigerant
Caution: The
Recovery-Recycle-Recharging
equipment
has
special fittings to avoid
cross
contamination with
R-
12
systems.
Do not attempt to adapt
this
unit for
R-12
as
system
failure will
result.
Warning: Follow the safety procedures
as
defined at the
beginning of the section.
Caution: The unit's overfill limitation mechanism has
been
calibrated specifically for
use
with
the 50
lb.
(23 Kg)
refillable refrigerant
tank.
As the refrigerant is recovered it is passed through
an oil separator and
a
filter drier before it is allowed
to enter the refrigerant tank. When it is dry the
moisture indicator turns green.
May 1996 8-47
The Aston Martin Lagonda Diagnostic System
Installation Instructions E:MB^^?
Introduction The Aston Martin Diagnostic System
This guide contains instructions for the installation
of the Portable Diagnostic Unit hardware in Aston
Martin Dealer workshops. To achieve maxinnum
benefit from the system, please follow the
instructions carefully. The following System
Diagram shows the principal system components
and panel details.
This introduction briefly describes the system and
its capabilities. This is followed by the Installation
and Power-Up procedures which give detailed
instruaions on how to start the system and access
the self-contained Interactive
Training
Programme.
The subsequent sections detail the fault diagnosis
and maintenance procedures.
WARNING:
The equipment must
only
be used by
trained
personnel.
Care should
be taken to use the
equipment in accordance with the operating
procedures.
Observe
all safety
warnings
in this
guide.
If any part of
the system is damaged do not
use it. Call your local CenRad
Service
Centre
immediately
for a
substitute
part.
Refer to
'Parts
Ordering'.
The Aston Martin Diagnostic System is a new
generation diagnostic
tool
which fulfils
a
number of
functions in aiding the technician to quickly and
accurately locate faults. The heart of the system is
the Portable Diagnostic
Unit,
a
lightweight powerful
computer/measurement system providing a step-
by-step user friendly interface for the technician.
PDU functions include:
Data Logger - The ability to monitor and record
control module signals even whilst the vehicle is
being driven.
On-Line Help-Containing detailed descriptions in
the
operation
ofthevehicleselectroniccomponents.
Vehicle Setup - The ability to setup various
adjustable parameters to their optimum settings.
Diagnostic Trouble Codes - The ability to extract
recorded fault information from the DB7's control
modules.
Each of
these
funaions is described in detail in the
PDU Users Guide.
WARNING: If
the system is used to measure high
voltages,
these voltages can appear on the pins of
other
connectors in
the
system.
Ensure
that socket
covers
are
fitted
on
unused
sockets.
Ensure
that all
connections
are
made
prior to
applying the high
voltage to
the
probes.
Do not
leave the equipment
unattended
in
this
state.
The maximum
voltage
that may be applied
between the
test
probes is 150
volts
AC or DC.
Radio Interference Statements
This digital apparatus does not exceed the Class A
limits for radio noiseemissionsfromdigital apparatus
as set
out
in
the radio interference regulations of the
Canadian Department of Communications.
This equipment has been tested and found to
comply with the limits for Class A digital device
pursuant to part 15 of the Federal Communications
Commission (FCC) rules. However, operation in
close proximity to domestic communication
equipment may cause interference. It is the
responsibility of the user to avoid or correct this
condition.
9-2 May 1996
The Aston Martin Lagonda Diagnostic System
Installation Instructions ^7
Base Station installation
It is recommended that the base station is wall
mounted (Fig 3). Alternatively it may be mounted
on a bench. The base station houses the CD-ROM
drive and power supplies.
Note: The electronic module should only be fitted
after
the base station has been installed.
Wall Mounting
It
is
importantthatthefollowing points be considered
before carrying out the mounting procedure.
The location should be close to the vehicle repair
bays.
The base station will require a power outlet
close by, such that the 2m mains lead will
comfortably reach the outlet.
Thewall plate should be attached with fourfasteners,
each of which has a minimum pull-out strength of
300 kg (662 lb). Thefourfasteners are not supplied,
as the type of fastening will depend on the wall
material.
The mounting holes in the wall plate are
8mm diameter with a maximum clearance for a
socket spanner of 30mm. It is recommended that
6mm diameter bolts are used to secure the wall
plate.
WARNING: The mains power outlet must be dose
to the equipment and be clearly recognisable as
the power source for safety reasons.
French Market
Only:
Do not connect the PDU
equipment
to
IT(lmpedante Terre) power systems.
r
900mm
Figure 3. Wall Mounted installation
WARNING: This equipment must be earthed via
the
mains
lead through the outlet socket. In markets
where three pin main power outlets are not
available, a separate earth point must be used
Procedure
1.
Select a suitable location.
2.
Mark a horizontal line on the wall 900mm above
the floor (Fig 3)
3. Removethetwoscrewssecuringthewall mounting
plate to the base station and remove the wall
mounting plate.
4.
Holdthewall mounting plate up to the marked line
and mark four hole positions for the wall mounting
plate bolts.
5. Drill the wall to the correct diameter and depth
required for the four bolts.
6. Securely fasten the wall mounting plate to the
wall.
Lift the base station onto the wall mounting plate,
fit and tighten the two screws/washers to secure the
base station to the mounting plate.
CAUTION: The gap beneath the base station
should be maintained free from obstructions to
allow a flow of air under the unit for cooling.
9-8 May 1996
^^?
The Aston Martin Lagonda Diagnostic System
I nstal lation I nstructions
Bench Mounting
The base station may also be mounted on a bench, which
must be in a safe position, stable and protected form
hazards and impacts. The base station must be mounted
at the back of the bench. 'Z' clips are provided for
permanent mounting. The bench surface must be kept free
from dust at all times.
CAUTION:
A gap under the base station must be
maintained free from obstructions to allow a flow of air
under the unit for cooling.
Electronic Module installation
WARNING: The base station electronic module must be
disconnected from the mains supply prior to installation/
removal from the base station assembly. DO NOT
reconnect to the mains supply until the module is safely
fitted into the base station. This unit must be earthed.
Note:
Users in North America are advised to replace the
ceramic mains fuse in the electronic module with theglass
fuse supplied.
Procedure
1.
Unlock the base station door
2.
Pull the right spring-loaded hinge (Fig 4-1) and
remove the door.
3. Removetheelectronicsmodulefrom the packaging
and place it on a firm surface.
4.
Remove the two screws and washers from the front
of the module (Fig 4-3).
5. Insert the mains power lead into the socket at the
rear of the module Fig 4-4), DO NOT CONNECT
TO THE MAINS SUPPLY.
6. Insert the two guide pins on the sides of the module
(Fig 4-5) into the base station slots.
7. Slide the module into the base station until fully
home,
raise the front so that it is level and draw it
slightly forward.
8. The two connectors on the front of the module will
appear through the matching holes in the base
station.
Support the module whilst refitting the two
retaining screws and washers (Fig 4-6).
9. Secure the mains lead to the underside of the base
station using the two cable ties provided (Fig 4-7).
10.
If bench mounting, the base station will need to be
turned on its back to install and secure the mains
lead.
11.
Refit the base station door.
CAUTION: Take care to avoid the sharp edges of the
module whilst installing. Take care to support the
module from the underside until the mounting
screws are secured.
Figure 4. Electronic Module Installation
May 1996 9-9
The Aston Martin Lagonda Diagnostic System
Installation Instructions ^=2?
Warranty
The Aston Martin Diagnostic System is covered by a one year warranty. Should any of the electrical components
fail during the warranty period, contact your local GenRad Service Centre for a replacement part. Note that the
warranty does not include physical damage.
Spare Parts
Refer to the Aston Martin Diagnostic System Users Guide for a full parts list. All spare parts should be obtained from
your local GenRad Service Centre who can advise you on current prices.
Servicing and Maintenance
CA UTION: With the exception of those parts listed in this section, there are no user serviceable parts within the
system. All servicing must be carried out by GenRad Service Centres.
Battery Testing.
The NICAD batteries fitted in the PDU are designed to be rechargeable and should normally last through many
recharge cycles. Battery life of three to five years can be expected. The capacity of new batteries improves after
several charging cycles. After extended use, they may require renewing. The following procedure will assist you to
determine when renewal is required. Do not use this procedure with new batteries or with a new PDU.
Testing Procedure
1.
Remove all cables from the PDU.
2.
Switch the PDU on and leave it until it switches off (the power on indicator will extinguish)
3. Connect the PDU to the base station for at least 12 hours charging.
4.
Remove all cables from the PDU, switch on the PDU and start timing.
5. If the PDU switches off in less than 30 minutes, the batteries should be renewed.
Changing the Battery Pack
CAUTION: Always read and follow safety warnings and instructions printed on the equipment. The rechargeable
NICAD batteries fitted to the PDU are of a special type. They must only be substituted by GenRad approved parts.
Do not substitute the batteries with any other type. Always dispose of old batteries in compliance with local
recycling regulations.
Battery Changing Procedure
A spare battery pack kit (0975) is available from your local GenRad Service Centre.
Figure 23. Battery cover screw Figure 24. Battery pack
9-22 May 1996