COMPRESSOR DISASSEMBLY
CB5A-021 page 14/24
Failure to disconnect and lockout
electrical power or engine drive before
attempting maintenance can cause
severe personal injury or death
Hazardous
machinery can
cause serious
personal injury.
Failure to relieve system pressure prior
to performing compressor service or
maintenance can cause serious
personal injury or property damage.
Hazardous pressure
can cause serious
personal injury or
property damage
Venting pressure from the compressor
piping could release explosive gas to
the atmosphere creating an explosion
hazard, possibly causing severe
personal injury or death.
Hazardous gases
can cause property
damage, personal
injury or death
NOTICE:
Before starting work on the compressor, make sure
all pressure is bled off on both the suction and
discharge.
1. Remove the center head capscrews from the
cylinder head. Remove the outer cylinder head
capscrews.
2. Remove the cylinder head assembly and cylinder
head O-rings from the cylinder. The suction and
discharge valve assemblies will come off with the
cylinder head. For valve replacement instructions,
refer to the "Valve Replacement" section of this
manual.
3. Removal of the piston requires a 3" adjustable
spanner wrench with 1/4" pins, such as Blackmer PN
790316.
a. Rotate the flywheel by hand to bring a piston to
top dead center of the cylinder.
b. Remove the piston nut by turning the nut
counterclockwise. (The nylon locking insert in
the piston nut must be replaced during
reassembly.)
c. To remove the piston from the cylinder, turn it
counterclockwise with the use of the adjustable
spanner wrench. For removal and replacement
of the piston rings, refer to the "Compressor
Assembly" section.
d. Remove the thrust washer and any shims. Keep
the shims and piston together.
e. Repeat these steps for the other piston.
4. Remove the cylinder capscrews.
5. Lift the cylinder and cylinder O-rings from the
crosshead guide (or distance piece).
6. Packing Box Removal
a. Using an adjustable spanner wrench, remove
the packing box hold-down rings. (Replace the
nylon locking inserts in the hold-down rings
during reassembly.)
b. Remove the packing box and packing box O-
ring from each piston rod. Double-Seal models
will have a spacer ring and a second packing
box O-ring to remove from each piston rod.
c. For disassembly of the packing boxes, refer to
the "Seal (Packing) Replacement" section of this
manual.
7. Remove the crosshead guide capscrews, and lift the
crosshead guide and gasket off.
8. To remove the connecting rod assemblies, with the
crossheads attached, it may be necessary to drain
the oil from the crankcase. The piston rod is
permanently attached to the crosshead to form a
single assembly. Do not attempt disassembly.
a. Remove the inspection plate from the
crankcase.
b. Remove the locknuts from the connecting rod
bolts. This will release the connecting rod cap
(the lower half of the connecting rod) and the two
halves of the bearing insert. The connecting rod
and the connecting rod cap are marked with a
dot on one side so that they can be properly
aligned when reassembling.
c. Lift the crosshead assembly and connecting rod
off the top of the crankcase.
NOTICE:
The connecting rod parts are not interchangeable
and must be reassembled with the same upper and
lower halves. To avoid confusion, work on one
connecting rod at a time, or mark the individual
halves with corresponding numbers.
9. Remove the opposite connecting rod and crosshead
assembly in the same manner as outlined in step 8.
10. Rest the crosshead assembly on a bench. Carefully
drive the wrist pin and wrist pin plugs out of the
crosshead and connecting rod using a suitable pin
driver or an arbor press. Removal of the pin releases
the crosshead assembly from the connecting rod.
11. If necessary, the wrist pin bushings can be replaced
after the crossheads are removed. New bushings
MUST
be honed to the proper size after installation.
See Table 10 - Wrist Pin Bushing Dimensions.
