LINK 1891551 - Caterpillar

Illustration 1. Location of 147-6632 Valve Mounting Group.
Illustration 2. Location of 138-6773 Screen Assembly and 6V-8397 O-Ring Seal. 138-6773 Screen Assembly Cleaning Procedure
Personal injury can result from working with cleaning solvent. Because of the volatile nature of many cleaning solvents, extreme caution must be exercised when using them. If unsure about a particular fluid, refer to the manufacturer's instructions and directions. Always wear protective clothing and eye protection when working with cleaning solvents. Always ensure there is adequate ventilation.
1. Open the hydraulic pump access panel located on the top platform. See Illustration 1.2. Remove 6V-8397 O-Ring Seal and 138-6773 Screen Assembly.3. inspect 138-6773 Screen Assembly for damage. If necessary, replace the screen.4. Wash the 138-6773 Screen Assembly in clean, nonflammable solvent.5. Re-install the 6V-8397 O-Ring Seal and 138-6773 Screen Assembly.If the fan speed remains slow after cleaning the 138-6773 Screen Assembly, margin pressure may need to adjusted. Refer to the "Fan Drive Pump Margin Pressure-Test/Adjust" procedure on pages 92 and 93 in Service Manual Module, SENR1367.
Adaptable To: The above 138-6773 Screen Assembly Cleaning Procedure is effective with 992G (7HR1-Up) Wheel Loaders.