Gaging Procedure - Chevrolet 1988 Light Duty Truck Repair Manual

1B1-14 A-6 AIR CONDITIONING COMPRESSOR
Figure 30 — Installing the Piston during the
Gaging Operation
Im po rtant
• Do not install the shoe discs (34) on the
rear of the piston (32).
9. Rotate the shaft and axial plate (39) until the high
point of the axial plate is over the No. 1 piston
cylinder bore.
Lift the axial shaft assem bly (39) up a little out of
10
.
front cylinder half (29).
• Hold the front thrust races and bearing (" zero"
race, race bearing, " zero" race) against the
axial plate hub.
Position the No. 1 piston (32) over the No. 1 cylinder
11
.
bore (notched end of the piston being on the bottom
and the piston straddling the axial plate) and lower
the shaft to allow No. 1 piston to drop into its bore
(figure 30).
Repeat step 11 for pistons Nos. 2 and 3.
12
.
Install the rear cylinder half (42) on the pistons,
13.
aligning the cylinder with the discharge cross-over
tube hole in the front cylinder.
• Tap the piston into place using a plastic mallet
or piece of clean wood and a hamm er (figure
31).
14. Position the discharge cross-over tube opening
between a pair of com pressing fixture bolts to perm it
access for the feeler gage.
15 Install the top plate to J 9397.
.
T ig h ten
Nuts to 20 N m (15 ft. lbs.).

GAGING PROCEDURE

Tools Required:
J 8001 Dial Indicator Set
J 9397 Com pressing Fixture
J 9402 Piston Assem bly Tray
J 9661-01 Feeler Tension Gage Set
Two gaging procedures provide the running tolerances.
The first procedure determ ines the size shoe discs to
p ro v id e at e a c h p is to n
(0.0016-0.0024-inch) total preload between the seats and
the axial plate at the tightest place through the 360
degree rotation of the axial plate. The bronze shoe discs
are available in 0.013 mm (0.0005-inch) variations.
The second procedure, perform ed at the rear shaft
thrust bearing and race pack, provides a 0.064-0.077 mm
(0.0025-0.0030-inch) preload between the hub surfaces of
the axial plate, and the front and rear hubs of the cylinder.
Fourteen steel thrust races, including a basic " zero" race,
are available in 0.013 mm (0.0005-inch) increments. Use
J 9661-01 for gaging the shoe disc size. Use J 8001 to
determ ine the thrust race size.
1. Measure the clearance between the rear ball of the
No. 1 piston and axial plate in the following manner:
a. Select a com bination of oiled feeler gage
leaves to fit snugly between the ball and axial
plate.
b. A tta c h J 9661-01
distributor point checking scale may be used.
c. Pull on the spring scale to slide the feeler
gage stock out from between the ball and axial
plate. Note the reading on spring scale as the
a 0 .0 4 1 -0 .0 6 1 mm
to th e fe e le r g a g e . A