Transferring Compressor Clutch; Figure 4-15.Removing Bypass Piston Plug; Figure 4-16. Compressor Clutch - Carrier GR-45 Operation And Service

NOTES
1 Service replacement compressors are sold
without service valves. Valve pads are
installed in their place. The optional
unloaders are not supplied, as the cylinder
heads are shipped with plugs. Customer
should retain the original unloader valves
for use on the replacement compressor.
2 The piston plug that is removed from the
replacement compressor head must be
installed in the failed compressor if
returning for warranty or core credit.
3 Do not interchange allen-head capscrews
that mount the piston plug and unloader,
they are not interchangeable.
4 Check oil level in service replacement
compressor. (Refer to paragraphs 1.3 and
4.20.3.)
f. Remove the three socket head capscrews from the
cylinder head(s) that have unloader valves installed.
See Figure 4-15. Remove the unloader valve and by-
pass piston assembly, keeping the same capscrews
with the assembly. The original unloader valve must
be transferred to the replacement compressor. The
plug arrangement removed from the replacement is
installed in the original compressor as a seal. If piston
is stuck, it may be extracted by threading a socket
head capscrew into top of piston. A small Teflon seat
ring at the bottom of the bypass piston plug must be
removed.
GASKET
COMPRESSOR
HEAD
BYPASS
PISTON
PLUG

Figure 4-15.Removing Bypass Piston Plug

g. Remove the pressure switches and install on replace-
ment compressor after checking switch operation (re-
fer to paragraph 4.10).
h. Remove clutch assemble and retain original clutch
key. Install on replacement compressor. Refer to
paragraph 4.20.2.
i. Install compressor in unit by performing the removal
steps in reverse. It is recommended that new locknuts
be used when replacing compressor. Install new gas-
kets on service valves and tighten bolts uniformly.
j. Leak check connections and replace filter- -drier. Re-
fer to paragraph 4.6.
k. Using refrigerant hoses designed for vacuum service,
connect a vacuum pump (see Figure 4-5) and evacu-
SPRING
FLANGE
COVER
CAPSCREWS
(NOT INTERCHANGEABLE WITH
CONTROL VALVE SCREWS)
ate compressor to 500 microns. Front seat both man-
ifold valves to isolate the pump.
l. Start unit and check refrigerant level (refer to para-
graph 4.8.1).
m.Check compressor oil level (refer to paragraph
4.20.3). Add or remove oil if necessary.
n. Check compressor unloader operation.
o. Remove manifold gauge set.

4.20.2 Transferring Compressor Clutch

To remove a clutch (see Figure 4-16) from a compressor
and install on a replacement compressor, do the
following:
1. Compressor (typical)
2. Seal Cover
3. Coil
4. Rotor

Figure 4-16. Compressor Clutch

a. Using a wrench on the armature flats to keep it from
turning, remove the special bolt holding it to the
shaft.
b. Using special tool (CTD Part Number 07- -00242
- -01), remove the rotor nut and rotor. Retain original
key.
c. Noting the position of the wire, remove the three bolts
holding the coil to the compressor.
d. Remove every other bolt from the seal cover of the
new compressor in the same manner as the original
compressor. Mount the coil assembly with the wire in
the same orientation as it was mounted on the original
compressor. Tighten the mounting bolts to 45 lbs/ft
(6.2 mkg).
e. Mount rotor on shaft with rotor nut. Be sure pulley
turns freely without binding.
f. Install armature on shaft using original key and tight-
en mounting bolt to 20 ft/lbs (2.8 mkg).
g. Perform a check of the air gap between the inside face
of the armature and the mating face of the rotor. The
air gap should be measured with a minimum of 50
psig (3.4 bar) in the crankcase. A preliminary check
may be performed before the crankcase is pressurized
but a final check must be performed before the clutch
is operated. The gap should be between 0.016 and
4-11
1
2
3
4
5
6
5. Rotor Nut
6. Armature
7 Spacer Nuts
8. Snap Ring
7
8
T-295