PISTON 3793889 - Caterpillar

Sizing And Measuring Procedures
1 Install the valve guides into the cylinder head using the prescribed valve guide driver (see the Tool Guide). 2 Use 1P7458 Driver (1) and reamer (2) to presize the guide bore. See the chart below for the prescribed reamer. Later shoulderless grooved guides require sizing only if the size after installation is less than specified in the Service Manual. Use the 5P3536 Dial Bore Gauge Group to determine if honing or reaming is necessary. 3 Attach a drill to driver (1). Rotate the reamer at about 100 RPM. Use no lubricant during the reaming operation. 4 Use the 5P3536 Dial Bore Gauge Group (3) to measure the valve guide bore size. See the specific Service Manual for the correct inside diameter needed, to determine the amount of stock it will be necessary to remove. 5 To prepare for the honing operation, remove lug (4), if so equipped, from the wedge.6 Snap the wedge into feed block (5) by pushing it straight in against the inclined surface of the feed block, compressing spring clip (6). 7 Attach adapter (7) to the head with bolts (8). Insert 1P7455 Mandrel (9) into the adapter with the wedge and stone retainer side by side as shown. Tighten screw (10). Place the correct stone (11) into the mandrel as shown. Install universal yoke (12) onto the head and attach the 3/8" (9.53) universal drive shank and the washer on the yoke. 8 The mandrel must be trued-in each time a new stone or mandrel is used. To do this, clamp the correct truing sleeve in a vise. Turn stone feed-up knob (13) clockwise until the stone touches the sleeve; then turn one complete turn. Hone as outlined in steps 10-12, however, use only a light coating of honing oil on the stone and shoes. Inspect the stone and shoes after several strokes. The entire length of the shoes and stone should show contact with the sleeve. 9 Dress down any high spots on the shoes using a file. Use either an abrasive stick or a diamond dresser to dress the stone. Repeat the truing operation if necessary. 10 After truing the new mandrel, stone (11), and shoes, place the mandrel into the valve guide. Turn stone feed-up knob (13) clockwise until the stone touches the bore. Then turn knob (13) one more complete turn to hold stone (11) firmly against the bore, as the stone automatically expands while honing. Release lever (14) retracts stone (11) so feed-up knob (13) does not need readjusting when the tool is withdrawn and reinserted into the guide bore. 11 It is important to have the stone pressure adjusted properly. Too much pressure results in excessive stone wear; too little pressure causes the stone to glaze and cease cutting. To increase the stone pressure, turn cutting pressure control (15) clockwise. Use a 150-400 RPM electric drill to drive the honing tool.12 Turn the driving source on and stroke at a rate of