AVUM MAINTENANCE PROCEDURES
3-14. INTRODUCTION TO MAINTENANCE PROCEDURES (AVUM).
This section provides inspection, replacement and repair procedures for the Ground Handling Wheels Assembly, at the
Aviation Unit Maintenance (AVUM) level, authorized by the Maintenance Allocation Chart (MAC) provided in Appendix B.
A model number is included with the title of a procedure, unless the procedure applies to all models covered In this
manual. Defective items discovered during inspection, are replaced at AVUM level and repaired at AVIM level, unless
otherwise noted. The Repair Parts and Special Tools List (RPSTL), in Appendix C, may be referenced to aid in
identifying assemblies and component parts.
3-15. GROUND HANDLING WHEELS ASSEMBLY MAINTENANCE, Model 204-050-200-5 (AVUM).
The Ground Handling Wheels Assembly is group number 00 in the MAC. Maintenance performed on Ground Handling
Wheels Assembly, Model 204-050-200-5, at the AVUM level, consists of inspection, replacement and repair procedures.
Inspection procedures are presented for the hydraulic system, cradle assembly, and wheel assembly. Replacement
procedures are presented for the hydraulic pump assembly, hydraulic ram assembly, and wheel assembly Repair
procedures for the wheel assembly are presented In this section, but repair procedures for the hydraulic pump assembly
and cradle assembly are contained in Chapter 4, Section V Refer to Appendix C, Figure C-1-1, to identify assemblies of
Ground Handling Wheels Assembly, Model 204-050-200-5.
3-15.1 Hydraulic System Inspection, Model 204-050200-5 (AVUM) .
The Hydraulic System is group number 01 in the MAC, and consists of a hydraulic pump assembly, two hydraulic ram
assemblies, two hydraulic hoses, and connection fittings. This procedure is applicable to Ground Handling Wheels
Assembly, Model 204-050-200-5. The numbers in parenthesis refer to accompanying figure 3-2. Inspect the hydraulic
system as follows:
1. Check hydraulic hose assemblies (8 or 9) and fittings (27 & 28) for leakage. If a hose assembly or
fitting is leaking, tighten; if defective, replace defective components.
2. Check hydraulic rams (6) for leakage. If a hydraulic ram assembly is leaking, tighten hose (8 or
9) or fitting (27 or 28); if defective, replace hydraulic ram using procedures in paragraph 3-15.5.
Two types of hydraulic pump may be Installed on this model of the Ground Handling Wheels
Assembly. The older version pump with part number BU0953B is not repairable and will be
replaced by pump with part number 61780 upon failure. The pump with part number 61780 is
3. Check hydraulic pump (4 or 5) for damage and leaks. If pump is leaking, tighten connections; if
defective, replace hydraulic pump using procedures in paragraph 3-15.4.
4. Check hydraulic system components for cleanliness. If a component is dirty, wipe clean with dry
cleaning solvent (item 6, Appendix D). Observe all WARNINGS relative to the use of cleaning agents.
END OF TASK