MCi Crusader II 1989 Maintenance Manual page 481

Date 1-1-89
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MC~9 MAINTENANCE MANUAL
7. Attacf:l a charging hose to the Freon tan!(. Open the
tank valve slightly.permitting Freon to escape thus purging
the hose of air.
8. Connect the charging hose to the service fitting.
9. Open the Freon tank valve.
10. Turn in the upper receiver valve several turns. The
Freon will now enter the system.
11. The proper charge of Freon is 24 pounds (10.9 kg).
12. When the scale indicates this amount of charge,
backseat the receiver valve and close the Freon tank valve.
13. Disconnect the charging hose. Replace the cover
caps.
14. The system is now ready for operation·.
LUBRICATION
Too much oil in the system is as harmful as too little. To
ensure proper lubrication, the level should be maintained
within certain limits.
Sight gauges are located on both sides of compressor
crankcase. Oil level is correct when engine side sight gauge is
full and curb side sight gauge is empty.
After standing idle for any length of time, the compressor •
will normally pump crankcase oil into the system and
approximately 20 minutes of running time may be required
to bring it back to the crankcase.
After the unit has run at least one-half hour, the crankcase
temperature should be warm to touch. If cool, this indicates
.1e expansion valve adjustment is passing too much liquid
or there is excessive oil in the system. Oil level is always
lower in a cool crankcase due to cooling evaporating refrig-
erant causing oil to foam and be carried out into the system.
BELT TENSION
AIR CYLINDER
An air-operated conditioning compressor belt tension air
cylinder is installed to .keep the correct tension of A/C
compressor drive belts. Access to the air cylinder can be
gained through rear engine compartment doors. See figure
16-9.
Figure 16-9: Belt Tension Cylinder
MAINTENr>.NCE - The A/C compressor belt tension air
cylinder should be lubricated at regular intervals, approxi-
mately every 30,000 miles (48,000 km).
The recommended procedure is as follows:
1. Remove air feed hose from cylinder and apply a few
drops of SAE 30 or 40 engine oil into cylinder hose
connector.
2. Reconnect the hose, then reverse the air supply to the
cylinder to lubricate the other end of the cylinder.
3. Check the cylinder for air leaks and recondition it as
required.
NOTE: Do not attempt to disassemble air
.cylinder in coach.
REMOVAL AND DISASSEMBLY- Proceed as follows:
1. Shut off air supply by turning control valve handle to
compress the cylinder spring and relieve belt tension.
2. Remove drive belts.
3. Remove lock nuts and bolts securing rod ends to
mounting bracket on the engine cradle, and bracket on
compressor. Remove air cylinder from coach.
4. Disconnect feed and exhaust hoses at the air cylinder.
5. Remove the uniball ends from air cylinder assembly.
WARNING:Air cylinder end plate is under
50 to 60 lbs. (22.6-27.2 kg) spring pres-
sure. Care must be exercised to avoid
injury when disassembling the cylinder.
6. Using an arbor press, depress the piston rod into the
cylinder approximately 'h" (12.7 mm) before attempting to
remove retaining ring.
CAUTION: Avoid depressing piston .rod
beyond 1/2" (12.7 mm) as spring pressure
increases with more compression. Care
should be taken not to damage any
threaded surfaces.
7. Remove end plate retaining ring using a suitable pliers
and screwdriver if nec~ssary.
8. Slowly release pressure on piston rod and cylinder
assembly thus ?llowing the end plate to come clear of
cylinder.
9. Internal parts can now be removed for cleaning and
inspection. See figure 16-10.
INSPECTION AND REPLACEMENT - Inspect all 0-rings,
cups, felts and seals; replace if damaged. Inspect cylinder
bore and piston for scoring and replace if damaged. Refer to
Specifications at end of this section for spring rate tension
and replace if not within tolerances. Inspect retaining ring
and replace if bent or damaged.
REASSEMBLY - follow this procedure:
1. Coat all new parts with SAE 30 or 40 engine oil prior to
assembly.
2. Reassemble the cylinder in reverse order of disas-
sembly.
3. Hold the cylinder in an upright position and install the
spring and oil felt in position over the boss on the lower end
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