water pump ASTON MARTIN DB7 1997 Workshop Manual

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Electrics
Wiper Motor / Alternator - Removal Procedures
6.2.01 Windscreen Wiper Motor 6.3.01 Alternator
Procedure

1.
Disconnect the battery.

2.
Disconnect the wiper motor multi-plug.
3. Remove the nut and lockplate (Fig 1-1) from the
motor gearbox shaft and release the drive bracket
from the shaft.
Figure 1. Windscreen Wiper Motor

4.
Remove three nuts (Fig
1
-2) and remove the motor
from its mounting bracket.
Procedure

1.
Disconnect the battery earth
lead.

2.
Using a 3/8" ratchet handle, release the drive belt

tension.
Slip the belt from the water pump drive
pulley and from the alternator drive pulley.
3. Release the ignition leads from the support on the
alternator top mounting.

4.
Remove the alternator output lead cover, remove
the nut and washers and disconnect the alternator
output
lead.

5. Disconnect the electrical plug on the rear of the
alternator.
6. Remove the alternator lower mounting bolt.
Figure 1. Alternator Mountings
7. Loosen the alternator upper mounting bolt, support
the alternator, remove the upper bolt and the
alternator.
Replacement is the reverse of the removal procedure. The
drive belt is tensioned automatically by the spring loaded
idler on refitting the main drive belt.
May 1996 6-5

Air Conditioning
System Checking with the Manifold Gauge Set [n::S3^^?
Refrigerant Excessively Low.
Complaint.
Cooling is not adequate.
Air In The System.
Complaint.
Cooling is not adequate.
BLU£ LOW SIDE SlUE LOW SIDE MD HIGH SIDE
5.
6.
7.

Condition.

1.
The low side gauge is reading very low.

2.
The high side gauge reading very low.
3. No bubbles or liquid evident in the sight glass.

4.
The discharge air from the evaporator is warm.
Diagnosis.
System refrigerant excessively low. Serious leak

indicated.

Correction.

1.
Test the system for leaks.
Note: Partially recharge the
system
before testing the

system
for
leaks
to
ensure that leak detection is
obtained.
Depressurise the system.
Repair the leaks, and if necessary renew hoses or

units.

Check the compressor oil level. The system may
have lost oil due to leakage.
Evacuate the system using a vacuum pump.
Recharge the system with new refrigerant.
performance.

2.

3.

5.
6.
7.
8-42
Condition.
The low side gauge reading
is
constant and does not

drop.
The pressure should drop until the compressor
cycles (thermostat control)
The high side gauge reading is slightly high (or
slightly lower especially if a large fan is used to
substitute ram air).
The sight glass is free of bubbles or only shows an
occasional bubble.
Thedischarge air from theevaporator
is
only slightly

cool.

Diagnosis.
Non condensables present in the system. Air or
moisturepresent instead of afullrefrigerantcharge.
Correction.
Test the system for leaks. Test the compressor seal
area very carefully.
Depressurise the system. Repair the leaks, and if
necessary renew hoses or units.
Renew the drier bottle, probably water saturated .
Check the compressor oil level.
Evacuate the system using a vacuum pump.
Recharge the system with new refrigerant.
Operate the system and check the performance.
May 1996