2007/12/24 Caterpillar

Wheel Tractor-Scraper:

631G (S/N: DFA1-UP)

637G (S/N: DFJ1-UP)

Description of Change: New hoses and fittings are being used on certain Wheel Tractor-Scrapers. The new hoses will be routed away from the muffler bracket. The new hoses will prevent rubs on the muffler bracket. This change will eliminate leaks from the hoses that are rubbing.

Adaptable To: Table 1 shows the parts that are required for this procedure. This change is adaptable to the following machines:

• 631G (S/N: DFA1-330)

• 637G (S/N: DFJ1-358)

• 637G (S/N: DFJ360-360)

Removal of Hoses on Cushion-Hitch

1. Move the machine to a safe area. Secure the machine and lock out the machine.

Show/hide table

NOTICE
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. 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 Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Caterpillar products. Dispose of all fluids according to local regulations and mandates.

2. Before removal begins release the hydraulic oil pressure in the machine. Apply a vacuum to the hydraulic system in order to prevent an oil loss, or drain the hydraulic tank.

Show/hide table



Illustration 1	g01443235

3. Remove tube assembly (3) and elbow (2) from cushion-hitch valve (1) .

4. Remove hose (7) and clip (4). Retain the hardware for later use.

5. Remove hose (6) and elbow (5) from the plate on the front of hitch.

Show/hide table



Illustration 2	g01444047

6. Remove hose (8) and elbow (9) from the hydraulic return tube.

7. Remove elbow (10) and back tee (11) from the plate on top of case. Save connector (12) from tee fitting for later use.

   Note: 637G Push-Pull machines will have two tees here.

Installation of New Hoses on the Cushion-Hitch

Show/hide table



Illustration 3	g01443243

1. Install hose assembly (20) to the valve and fitting on the hydraulic suction tube. Secure hose assembly (20) to the top of the case with the hardware that was previously removed.

2. Install adapter (17) with O-Ring (18) and connector (12) that was removed previously to the port on the hydraulic return tube.

3. Install swivel tee (19) and two O-Ring Seals (13) to the back of union. This is located on the plate on the top of case. Connect hose assembly (16) from the cushion-hitch pump to the end of swivel tee (19) .

4. Install one O-Ring Seal (13), connector (14), O-Ring Seal (15), and hose assembly (16) to cushion-hitch valve (1). Connect hose assembly (16) to swivel tee (19). Swivel tee (19) is located on the top of the case.

Show/hide table



Illustration 4	g01444493

5. Secure hose assemblies (20) and (16) to the side of the cushion-hitch with clip (21) and hardware that was previously removed.

6. Secure hose assemblies (20) and (16) with two clips (22) and (23). Fasten clips with one bolt (24), two hard washers (25), and one nut (26) .

7. Install hose assembly (27) to the front of union. This is located on top of the case and connector (12) in hydraulic return tube.

8. Remove the vacuum from the tank. Refill the hydraulic tank with oil.

9. Check operation of cushion-hitch valve (1) .

10. Verify oil level in the tank and return the machine to operation.