PUMP GP-HYD 3848916 - Caterpillar

Introduction
If the height of the piston above the top face of the cylinder block is not within the tolerance that is given in Specifications, "Piston and Rings", the piston and the piston pin bearing must be replaced. If any of the following components are replaced or remachined, the piston height above the top face of the cylinder block must be measured:
Crankshaft
Cylinder head
Connecting rod
Piston pin bearing
PistonThe correct piston height must be maintained in order to ensure that the engine conforms to the standards for emissions.Note: The top of the piston should not be machined. If the original piston is installed, be sure that the original piston is assembled to the correct connecting rod and installed in the original cylinder.Required Tools
Table 1
Required Tools
Part Number Part Name Qty
8T-0455 Liner Projection Tool Group 1 Inspection Procedure
Illustration 1 g00323908
8T-0455 Liner Projection Tool Group
(1) 1P-2403 Dial Indicator
(2) 1P-2402 Gauge Body
(3) 1P-5507 Gauge Block
Use the 8T-0455 Liner Projection Tool Group in order to measure the piston height above the top face of the cylinder block. Use the gauge block (3) in order to zero the dial indicator (1).
Illustration 2 g00326383
Measurement of the piston height
(1) 1P-2403 Dial Indicator
(2) 1P-2402 Gauge Body
Position gauge body (2) and dial indicator (1) in order to measure the piston height above the top face of the cylinder block. Slowly rotate the crankshaft in order to determine when the piston is at the highest position. Record this dimension. Compare this dimension with the dimensions that are given in Specifications, "Piston and Rings".