Page 269 of 284

AIR-CONDITIONING-Service Adjustment Procedures 24-33
2080113
6
Refrigerant
Compressor
Cl”“” tester T-7
Leak
, tester
pick up
tube
b/
2OUO316
TESTING SYSTEM FOR LEAKS N24FFA8
A leak is likely to occur where two components are connected
together. See illustration for possible locations.
The Leak Detector Torch is a butane gas-burning torch used to
locate a leak in any part of the refrigeration system. Refrigerant
gas drawn into the sampling or “sniffer” hose will cause the flame
to change color in proportion to the size of the leak. A very small
leak will produce a flame varying from yellowish-green to bright
green. A large leak will produce a brilliant blue flame.
Caution
Do not use the lighted detector in any place where explosive
gases, dust or vapors are present. Do not breathe the
fumes
that are produced by the burning of refrigerant gas. Large
concentrations of refrigerant in the presence of a live flame
become dangerously toxic.
If the flame remains bright yellow when the tester is removed
from a possible leak point, insufficient air is being drawn in through
the sampling tube, or the copper reaction wire is dirty.
(1) Assemble leak detector as shown be sure detector is seated
tightly over torch gasket.
(2) Holding torch upright screw-in butane charger (clockwise) until
punctured. (Do not use force).
(3) Screw-out butane charge (counterclockwise) about l/4 turn.
(4) Point torch away from body-then light escaping gas with
match. Always keep torch in upright position.
(5) Adjust flame by turning cartridge in or out as required.
(6) Allow 30 seconds to heat copper reaction wire.
Caution
Never remove butane charger while torch is lighted or in the
presence of any open flame.
(7) Examine all tube connectors and other possible lead points by
moving the end of the sampling hose from point to point.
Always keep torch in upright position. Since R-12 is heavier
than air, it is good practice to place the open end of sampling
hose directly below point being tested. Be careful not to pinch
sampling tube since this will shut off air supply to flame and
cause a color change.
(8) Watch for a change in the color of the flame. Small leaks will
produce a green color and large leaks a bright blue color. If
leaks are observed at tube fittings, tighten the connection,
using the proper flare wrenches, and retest.
1 STB Revision
Page 271 of 284

AIR-CONDITIONING-Service Adiustment Procedures 24-35
CORRECTING LOW REFRIGERANT LEVEL Suction
Discharge gauge
gauge
I \- a/
gauge valve
II II Discharge gauge
Ho water
52°C i 125°F)
2OUO325
Since the refrigeration system is completely sealed, refrigerant level will not be low unless there is a leak in the
system.
Before adding refrigerant when the cause of 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.
(I) Close both gauge set manifold valves.
(2) Connect the suction gauge test hose to the suction port of the compressor. Connect the discharge gauge test
hose to the discharge port.
(3) Connect one end of long test hose to center manifold outlet, other end to refrigerant dispensing manifold.
(4) Close two dispensing manifold valves and open remaining dispensing manifold valve. Remove protective cap
from opened valve.
(5) Screw a can of R-12 to the opened manifold valve. Be sure gasket is in place and in good condition. Tighten
refrigerant can and manifold locking nut to insure a good seal. Do not overtighten. 8 to 11 Nm (6 to 8 ft.lbs.) is
sufficient 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
Never heat small cans of refrigerant over 52°C (125’F) as they may explode.
(7) Place the refrigerant 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 condensing of the refrigerant.
(9) Slightly loosen both test hoses at the gauge set manifold. Tighten the hoses as soon as the air is purged.
(10)Slightly loosen charging hose connection at gauge set manifold. This will purge air from the charging hose.
Tighten connection as soon as air is purged.
(1l)With vehicle windows open and hood up, operate engine at 1,500 rpm and jump the switch terminals located
on so the clutch will remain engaged.
(12)Place air conditioner control on air conditioner and place the blower switch on high.
(13)lf necessary, block the condenser to maintain a discharge pressure of 1,422 to 1,520 kPa (206 to 220 psi.).
System must be charged through the evaporator 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 that pressure registered at the suction service gauge does not exceed 345 kPa (50 psi). Keep refrigerant container upright.
(b) Add refrigerant gas until there is no foam visible at the sight glass.
(c) Close the suction gauge valve. Caution
Too much refrigerant in the system can cause abnormally high discharge pressures. Care must be
used so that the exact recommended amount of refrigerant is added after foam clears in the sight
glass.
(d) Close dispensing manifold valve. Remove test hoses and adapters from the service ports of compressor,
install protective caps at service ports and reconnect wiring. / STB Revision
Page 283 of 284

AIR-CONDITIONING - Compressor 24-47
SERVICE POINTS OF DISASSEMBLY N24TFAE
5. REMOVAL OF ROTOR ASSEMBLY
It may be necessary to lightly tap the rotor with a plastic
hammer.
2OY713
Front housing
Shaft pl&e
2OY789
I MB990?83-01 2OY790
2OY788
INSPECTION N24TGAC
l
Check the surface of the clutch hub for scoring or bluing.
l Check the surface of the rotor for scoring or bluing.
l Check the sealing surfaces for cracks, scratches and deforma-
tion.
l Check the front housing for cracks or scoring on the sealing
surfaces.
l Check the compressor shaft for scoring.
SERVICE POINTS OF REASSEMBLY N24THAH
14. INSTALLATION OF SHAFT PLATE
(1) Lubricate the shaft plate and a new O-ring with
compressor oil. Push the shaft plate and O-ring into the
front housing.
(2) Install the seal plate into the front housing with a
special tool.
13. INSTALLATION OF SHAFT SEAL
Lubricate the shaft seal with compressor oil. Install the
shaft seal on the shaft.
NOTE
Rotate the shaft seal lightly by hand to check that it is
fitted into the notch on the compressor shaft. evision
r