New Powered Access Handrail Is Now Available for Certain 990K and 993K Wheel Loaders {7254, 7256} New Powered Access Handrail Is Now Available for Certain 990K and 993K Wheel Loaders {7254, 7256} Caterpillar

Reference: Special Instruction , REHS8425 , "990K Wheel Loader Field Assembly Procedure"

Reference: Special Instruction , SEHS0293 , "Installation Procedure for the Power Access System (PAS) on Certain 993K Large Wheel Loaders"

Reference: Special Instruction, REHS1841, "General Welding Procedures"

A new powered access handrail is now available for the machines listed above. The new handrail is designed to improve the service life of the component.

The following changes are adaptable to the products within the listed serial numbers.

Rework Procedure

Show/hide table

Do not operate or work on this machine or work tool unless you have read and understand the instructions and warnings in the Operation and Maintenance Manuals and Owner's Manuals. Failure to follow the instructions or heed the warnings could result in injury or death. Contact your AVSpare dealer for replacement manuals. Proper care is your responsibility.

Show/hide table

Diesel engine exhaust contains products of combustion which may cause personal injury. Always start and operate the engine in a well ventilated area, and, if in an enclosed area, vent the exhaust to the outside.

Show/hide table

Shock/Electrocution Hazard! Do not work on this equipment unless you have read and understand the instructions and warnings in the Operation and Maintenance Manuals. Failure to follow the instructions or heed the warnings could result in serious injury or death.

Show/hide table

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, and the 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.

Show/hide table

Personal injury or death can result from fumes, gases and ultraviolet rays from the weld arc. Welding can cause fumes, burn skin and produce ultraviolet rays. Keep your head out of the fumes. Use ventilation, exhaust at the arc, or both, to keep fumes and gases from your breathing area. Wear eye, ear and body protection before working. Protect yourself and others; read and understand this warning. Fumes and gases can be dangerous to your health. Ultraviolet rays from the weld arc can injure eyes and burn skin. Electric shock can cause death. Read and understand the manufacturer's instructions and your employer's safety practices. Do not touch live electrical parts. See "American National Standard Z49.1, Safety in Welding and Cutting" published by the American Welding Society. American Welding Society 2501 N.W. 7th Street Miami, Florida 33125 See "OSHA Safety and Health Standards, 29 CFR 1910", available from U.S. Department of Labor. U.S. Department of Labor Washington, D.C. 20210

Show/hide table

Personal injury can result from flame cutting or welding on painted areas. The effect of gasses from burned paint is a hazard to the person doing the cutting or welding. Do not flame cut or weld on painted areas.

Procedure to Install Powered Access Handrail on 990K Wheel Loaders

Illustration 1	g06428317
566-4142 Handrail Gp (1) 563-4618 Handrail As (2) 550-1130 Handrail As (3) 563-4619 Handrail As (4) 457-0270 Bushing (5) 4W-0435 Quad Ring Seal (6) 8T-4222 Plated Washer (7) 9X-2041 Screw (8) 564-9372 Spacer (9) 8T-4223 Hard Washer (10) 8T-6868 Bolt (11) 473-7161 Handrail As (12) 550-1118 Handrail Gp (13) 550-1115 Handrail Gp (14) 354-0501 Bushing (15) 4W-2754 Quad Ring Seal

Reference: For installation instruction, refer to Install Handrail section in the Special Instruction , REHS8425 , "990K Wheel Loader Field Assembly Procedure".

Note: The part numbers for the new handrails may not match the part numbers in the Special Instruction.

1. Apply grease on all the seals before assembly.

2. Replace the existing internal bushings and dust seals with bushing (4) and quad ring seal (5) for handrail joints.

   Note: If required, use plated washer (6) and screw (7).

Procedure to Install Powered Access Handrail on 993K Wheel Loaders

Illustration 2	g06428016
550-1119 Handrail Gp (2) 550-1127 Handrail As (3) 550-1130 Handrail As (4) 457-0270 Bushing (5) 4W-0435 Quad Ring Seal (6) 8T-4222 Plated Washer (7) 9X-2041 Screw (8) 550-1114 Handrail As (9) 8T-4223 Hard Washer (10) 8T-4648 Bolt (11) 564-9372 Spacer (12) 473-7144 Handrail As (13) 550-1118 Handrail Gp (14) 550-1115 Handrail Gp (15) 354-0501 Bushing (16) 4W-2754 Quad Ring Seal

Reference: For installation instruction, refer to Install Handrail section in the Special Instruction , SEHS0293 , "Installation Procedure for the Power Access System (PAS) on Certain 993K Large Wheel Loaders".

Note: The part numbers for the new handrails may not match the part numbers in the Special Instruction.

Show/hide table

Illustration 3	g06428436
(D1) 16.75 mm (0.659 inch) diameter (A) 503-8371 Rear Bumper Ar

Show/hide table

Illustration 4	g06428442
503-8371 Rear Bumper Ar (D2) 52.6 mm (2.07 inch) (D3) 112.6 mm (4.43 inch) (D4) 227.7 mm (8.96 inch) (W1) Slot weld two nuts (1) 8T-3597 Weld Nut

1. Drill two holes of diameter (D1) on the rear bumper (A) as per the dimensions shown in Illustration 4.

2. Weld two nuts (1) on two holes.

3. Apply grease on all the seals before assembly.

4. Replace the existing internal bushings and dust seals with bushing (4) and quad ring seal (5) for handrail joints.

   Note: If required, use plated washer (6) and screw (7).