SUPPORT AS 1749725 - Caterpillar

DO NOT ATTEMPT TO DISCONNECT LINES OR REMOVE PLUGS IN THE CUSHION HITCH CIRCUIT UNTIL THE ENGINE HAS BEEN SHUT OFF FOR AT LEAST FIVE MINUTES. The five minute wait permits oil pressure in the accumulators to be relieved. The hissing sound can be heard at the selector lever while the system is being bled. If the engine is shut off when the machine is in cushion ride, the hitch will lower as the circuit is bled. DO NOT PLACE HANDS OR FEET AROUND HITCH COMPONENTS UNTIL THE HITCH IS COMPLETELY LOWERED. Failure to heed this warning can result in the sudden release of high pressure oil.
1. Drain hydraulic tank-capacity 38 U.S. Gal. (144 liters).2. Bleed air reservoirs (tractor and scraper). 3. Disconnect air lines from inversion valve (3). Disconnect remaining air lines from engine dash.4. Remove mounting brackets (1) holding hydraulic hoses, air lines, and electrical cables to hitch.5. Disconnect hydraulic lines at implement control valve (2).6. Remove front horizontal hitch pin retaining nut. Remove rear hitch pin retaining nut. 7. Remove front bushings (5) from both pins using 1/2"-13NC forcing screws. 8. Place jack stands under draft tube and raise scraper to fully extended cushion hitch load cylinder.9. Secure front of tractor to lift truck and support tractor. If tractor is equipped with attachment parking brake (two air lines going to each rotochamber), release tractor brakes as follows:a. Disconnect air lines to the apply side of the rotochamber and pressurize the apply side of the rotochamber with shop air.b. Disconnect the air line to the parking lock release mechanism on the lower side of the rotochamber. Apply shop air to the lock release mechanism and maintain the pressure.c. Relieve shop air pressure to the apply side of the rotochamber and the brakes will release.d. Relieve the pressure to the lock release mechanism, and reconnect all air brake lines. 10. Install horizontal hitch pin puller, tool (A) and remove front hitch pin. 11. Remove rear hitch pin using tool (B).12. Move the tractor away from the scraper with a lift truck. A lift truck is not required for the 666 Tractor.