GMC S Series 1994, Repair Manual

Page: 38 / 919

1 - R E D I N S U L A T O R
2 - H I G H P R E S S U R E
C U T O F F S W I T C H
l
' J
3 - " 0 " R I N G
4 - S W I T C H
R E T A I N I N G
R I N G
’ o
520041-1D1
Fig. 30 High Pressure Cut-Off Switch and Retainer
□ Install or Connect
1. Check sw itch cavity and O -ring groove in the rear head
for dirt or foreign m aterial and clean as necessary. Install
new O -ring coated with clean 525 viscosity refrigerant
oil into groove in sw itch cavity.
2. Lubricate the sw itch housing with clean 525 viscosity
refrigerant oil and carefully insert switch into switch
cavity until switch bottom s in cavity.
3. U sing J 5403 snap ring pliers, install switch retaining
ring with high point o f curved sides adjacent to the
sw itch housing. Be sure retaining ring is properly seated
in the sw itch cavity retainer ring groove.
COMPRESSOR LEAK TESTING
(EXTERNAL AND INTERNAL)
Bench-Check Procedure
1. Install Test Plate J 9 6 2 5 -A on Rear Head o f compressor.
2. Using J 3 8 1 0 0 -B R efrigerant Recovery System , attach
center hose o f m anifold gage set on charging station to a
refrigerant drum standing in an upright position.
3. C onnect Charging Station high and low pressure lines to
corresponding fittings on Test Plate J 9 6 2 5 -A , using J
5420 G age A dapters if hoses are not equipped with valve
depressors.
• Suction port (low -side) o f com pressor has large
internal opening. D ischarge port (hi-side) has
sm aller internal opening into com pressor.
4. O pen low -pressure control, high-pressure control and
refrigerant control on Charging Station to allow
refrigerant vapor to flow into com pressor.
5. Using a leak D etector, check for leaks at Pressure Relief
Valve, com pressor shell to cylinder, com pressor front
head seal, and com pressor Shaft Seal. A fter checking,
shut o ff low pressure control and high pressure control on
C harging Station.
6. If an external leak is present, perform the necessary
corrective m easures and recheck for leaks to make
certain the leak has been corrected.
7. R ecover the R efrigerant.
8. D isconnect both Gage A dapters J 5420 from the Test
Plate J 9 6 2 5 -A .
9. Add 90 ml (3 oz.) new 525 viscosity refrigerant oil to the
com pressor assem bly. Rotate the com plete com pressor
assem bly (not the crankshaft or drive plate hub) slow ly
several turns to distribute oil to all cylinder and piston
areas.
10. Install a M9 x 1.25 threaded nut on the com pressor
crankshaft if the drive plate and clutch assem bly are not
installed.
11. Using a box-end w rench or socket and handle, rotate the
com pressor crankshaft or clutch drive plate on the
crankshaft several turns to ensure piston assem bly to
cylinder wall lubrication.
12. C onnect the Charging Station high pressure line or a high
pressure gage and G age A dapter J 5420 to the Test Plate J
9 6 2 5 -A high side connector.
13. Attach an A dapter J 5420 to the suction or low pressure
port o f the Test Plate J 9 6 2 5 -A to open the Schrader-type
valve.
Oil will drain out o f the com pressor suction port adapter
if the com pressor is positioned with the suction port
dow nw ard.
14. A ttach the com pressor to the H olding Fixture
J 2 5 0 0 8 -A using m etric m ounting screws. Clam p the
com pressor H olding Fixture in a vise so that the
com pressor can be m anually turned with a wrench.
15. Using a w rench, rotate the com pressor crankshaft or
drive plate hub ten (10) com plete revolutions at a speed
of approxim ately one-revolution per second.
Turning the com pressor at less than one-revolution per
second can result in a low er p u m p -u p pressure and
disqualify a good pum ping com pressor.
16. O bserve the reading on HIGH pressure gage at the
com pletion o f the tenth (10th) revolution o f the
com pressor. The pressure reading for a good pum ping
com pressor should be 344.75 kPa (50 p.s.i.) or above. A
pressure reading o f less than 310.275 kPa (45 p.s.i.)
w ould indicate one or m ore suction and/or discharge
valves leaking, an internal leak or an inoperative valve.
The refrigerant m ust be recovered, com pressor
disassem bled and checked for cause o f leak. R epair as
needed, reassem ble and repeat the pum p-up test.
Externally leak test.
17. W hen the pressure pum p-up test is com pleted, recover
refrigerant from the HIG H side and rem ove the G age
A dapters J 5420 and Test Plate J 962 5 -A .
18. On the H R 100T /H R 110-M D com pressor, tilt the
com pressor so that the com pressor suction and discharge
ports are dow n. Drain the oil from the com pressor.
19. A llow the com pressor to drain for 10 m inutes, then
charge w ith the proper am ount of oil. T he oil may be
poured into the suction port.
If further assem bly or processing is required, a shipping
plate or Test Plate J 9 6 2 5 -A should be installed to keep
out air, dirt and m oisture until the com pressor is
installed.