ROTATING GP-PUMP 3909391 - Caterpillar

Illustration 1 g01329332 (1) The piston is symmetrical with a center crater. Lubricate the entire piston to 360° in zone (A) prior to assembly into the cylinder block. Use clean engine oil. (2) Top piston ring groove Install the piston ring with the side marked "UP-1" toward the top of the piston. The ends of the piston ring have a clearance when the piston ring is installed in a cylinder liner with a bore of 130 mm (5 inch). Clearance ... 0.40 0.05 mm (0.014 0.002 inch)The top piston ring has an increase in clearance for each 0.03 mm (0.001 inch) increase in the cylinder liner bore. Increase ... 0.09 mm (0.004 inch) (3) Intermediate piston ring groove Install the piston ring with the side marked "UP-2" toward the top of the piston. Width of groove in new piston for intermediate piston ring ... 3.053 0.013 mm (0.1202 0.0005 inch)Thickness of new intermediate piston ring ... 2.980 0.010 mm (0.1173 0.0004 inch)The ends of the piston ring have a clearance when the piston ring is installed in a cylinder liner with a bore of 130 mm (5 inch). Clearance ... 1.000 0.125 mm (0.0394 0.0049 inch)The intermediate piston ring has an increase in clearance for each 0.03 mm (0.001 inch) increase in the cylinder liner bore. Increase ... 0.09 mm (0.004 inch) (4) Oil control ring groove The ends of the oil control piston ring should be a distance of 180 degrees from the ring end gap when the oil control piston ring is assembled. The green colored portion of the piston ring must be visible at the ring end gap. Width of groove in new piston for oil control piston ring ... 4.052 0.012 mm (0.1595 0.0005 inch)Thickness of new oil control piston ring ... 3.980 0.010 mm (0.1567 0.0004 inch)The ends of the piston ring have a clearance when the piston ring is installed in a cylinder liner with a bore of 130 mm (5 inch). Clearance ... 0.45 0.15 mm (0.018 0.006 inch)The oil control piston ring has an increase in clearance for each 0.03 mm (0.001 inch) increase in the cylinder liner bore. Increase ... 0.09 mm (0.004 inch)After the piston rings have been installed, rotate the piston rings so that the end gaps are 120 degrees from each other. (B) Piston pin bore diameter ... 53.250 0.010 mm (2.0965 0.0004 inch)Thoroughly lubricate the piston pin with clean engine oil prior to assembly.