3-12. AIR BRAKE SYSTEM MAINTENANCE (CONT)
e. Air Compressor Assembly (Cont).
(2) Cylinder Block and Crankcase (Cont).
INSPECTION (SHEET 2 OF 3)
(e) Measure diameter of piston (18) at a 90 degree angle to wrist pin bore
using micrometer. Record measurement.
(f) Measure diameter of cylinder block bore associated with piston measured
above at a 90 degree angle to wrist pin using bore gage and micrometer.
(g) If difference between measurements in step (e) and (f) above is more
than 0.008 inch, either a new piston must be installed, cylinder block
(2) bore diameter must be increased to next larger diameter listed
below, or a new cylinder block must be installed.
Standard bore diameter
1.9995 to 2.0000 inches
0.010 inch oversize diameter
2.0095 to 2.0100 inches
0.020 inch oversize diameter
2.0195 to 2.0200 inches
(h) Repeat steps (e) through (g) above for other piston (18).
(i) Measure diameter of rear journal on crankshaft (27). If measurement is
less than 1.3779 inches, a new crankshaft must be installed.