GAUGE AS-OIL LEVEL (DIPSTICK) 1686865 - Caterpillar

215, 219, 225, 227, 229, 235, 245 ExcavatorsReference: Service Magazine, September 10, 1990, Page 6, "New Seals and Piston Nuts Used, New Head Bolt and Piston Nut Tightening Torques Used in Excavator Cylinders." Service Magazine, September, 24, 1990, Page 13 "Standard Oval and High Temperature Oval Head Seals Available For Certain Hydraulic Cylinder Applications."Caterpillar is shipping remanufactured excavator cylinders that are up to 0.25 mm (.010 in) larger in bore size than standard. The typical recommendation to reseal these cylinders has been to use just the standard seals.
Because excavator hydraulic systems operate at higher pressures, an additional oval head seal is necessary to reseal these cylinders. The oval head seal locates under the head flange and seals in the chamfer at the end of the cylinder tube. The oval head seal should be used in addition to the usual O-ring and backup ring combination.
The piston seal, wear ring and rod seals are the same as those contained in the standard seal kits or as listed in the appropriate Parts Manual. Refer to the first Reference Article for bore sizes and oval head seal part numbers.
Also, as a product improvement, Caterpillar is now assembling all new standard size excavator cylinders using the additional oval head seal. Add the oval head seal whenever any excavator cylinder is serviced.