ENGINE AR-PRIMARY 1403556 - Caterpillar

Personal injury can result from hydraulic oil pressure and hot oil.Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system.Make sure all of the attachments have been lowered, oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Caterpillar Tools and Shop Products Guide", for tools and supplies suitable to collect and contain fluids in Caterpillar machines.Dispose of all fluids according to local regulations and mandates.
Note: When you remove any internal parts from the pilot valve, assemble the correct parts at the original location.
Illustration 1 g00334078
Typical Example (A) Full stroke (B) ClearanceThe clearance is 0.43 0.30 mm (.017 .012 inch) .In order to adjust the rocker base for clearance (B) , make sure that the pilot line pressure is 3500 100 kPa (508 15 psi). In order to adjust this pressure, refer to "Main Pressure Setting" at the end of this information.Note: If the rocker plate for the middle control valve must be adjusted, follow Step