CYLINDER & SEAL GP-BOOM 3683219 - Caterpillar

Typical view of the 1W-8512 or 2W-6620 Scavenge Oil Pump Shaft (1), and 7W-7153 Gear (2), and bolt (3). Location of pump serial number (A), and typical break location (B).
The above method should be used so that the gear does not come off during operation, or damage the shaft during the installation process. If too much force is used when installing the gear, the shaft can be damaged and could break. If too little force is used when installing the gear, the gear could come off the shaft during operation. In either case, oil can accumulate in the rear section of the oil pan when the machine is driven uphill. This can lead to a problem of the crankshaft whipping the oil, causing the oil to blow out of the dipstick or breathers. This can cause low oil level and low oil pressure. When the machine is back on level ground, the symptoms will disappear. See the illustration for the typical location of the break on a damaged scavenge oil pump shaft (B).
The 8N-9164 Scavenge Oil Pump Groups starting with pump serial number 3049 were assembled with the new procedure. 1W-8508 Scavenge Oil Pump Groups starting with pump serial number 2699 were assembled with the new procedure. See the charts for effectivity.