T-354
7–14
7.8.4
Preparation
Suction and Discharge Valves
If the valve seats look damaged or worn, replace valve plate assembly. Always use new valves because it is diffi-
cult to reinstall used valves so that they will seat as before removal. Any valve wear will cause leakage.
Suction valves are positioned by dowel pins (see
). Do not omit the suction valve positioning springs.
Place the springs so that the ends bear against the cylinder deck (middle bowed away from cylinder deck). Use
new gaskets when reinstalling valve plates and cylinder heads.
Compression Rings
The compression ring is chamfered on the inside circumference. This ring is installed with the chamfer toward the
top. Stagger the ring end gaps so they are not aligned.
Figure 7.14 Suction Valve & Positioning Springs
1. Suction Valve
2. Suction Valve Positioning Spring
3. Valve Plate Dowel Pin
- - - - -
Figure 7.15 Piston Ring
The gap between the ends of the piston rings can be checked with a feeler gauge by inserting the ring into the piston
bore approximately one inch below the top of the bore. Square the ring in the bore by pushing it slightly with a piston.
The maximum and minimum allowable ring gaps are 0.33 and 0.127mm (0.013 and 0.005 inch) respectively.
Summary of Contents for 69NT40-541-306
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