Usage:
D250E (5TN1481-Up),
D300E (7FN800-Up) Articulated Trucks
- SUPPLEMENT: July 13, 1998
Service Magazine SEPD0423, Article 16, Page 19; June 29, 1998; "New Procedure Improves Quality Of Ride And Ease Of Service" for D250E (5TN1481-Up), and D300E (7FN800-Up) Articulated Trucks.
Disregard this article. This article will be rewritten and published at a later date. Until that happens, please call Duane Weaver (217-475-4813) if you have any questions.
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Reference: * Service Manual Module, SENR8640; Systems Operation Testing & Adjusting, D250E & D300E Articulated Trucks Steering, Suspension & Body Hoist Hydraulic System. This module is part of SENR8635 Service Manual.
Reference: * Service Manual Module, SEBU6903; Operation & Maintenance Manual; D250E & D300E Articulated Trucks; Page 91; "Suspension". This module is part of SENR8635 Service Manual.
A new procedure is used to improve ride and ease service.
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The suspension system may drop the machine suddenly, leaving no clearance between the axle housing, main frame, tires, and mud guards. Working in these areas can result in personal injury or death by crushing. Stay clear until the engine is stopped and the suspension is lowered to the service position.
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| NOTICE |
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Fluid Spillage Containment: Care must be taken to ensure fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to "Tools and Shop Product Guide, NENG2500", for tools and supplies suitable to collect and contain fluids in Caterpillar machines. Dispose fluids according to local regulations and mandates.
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1. Connect a bleed hose equipped with a suitable coupler and hand operated stop valve to the accumulator test point TPI. The valve must be closed and the free end secured in a suitable container.
2. Remove guard and protective cap from the top of the accumulator and connect the accumulator charging equipment to the gas valve. Connect pressure gauge and stop valve only. Do not connect the regulator at this stage.
3. Open the stop valve on the charging equipment and screw down the connector handle to open the accumulator gas valve.
4. Start the engine. Engage the "Power Down" and open the valve. The suspension will rise and the air and surplus oil will be expelled from the gas side of the accumulator. The accumulator should have been charged with a small quantity of oil during assembly to lubricate the top seal. If no oil is expelled, it will be necessary to remove the gas valve and pour oil into the accumulator until it reaches the level of the hole.
5. When the suspension is fully raised and the surplus oil has been expelled, close valve. Engage "Float". Stop the engine. Close the accumulator gas valve by unscrewing the connector handle.
6. Open the bleed hose valve and allow the suspension to fully lower.
7. Charge the accumulator with nitrogen gas to a pressure of 2480 kPa (360 psi). Oil will be expelled from the bleed hose as the accumulator piston is forced to the bottom of the tube. The piston must move fully to the bottom of the tube if a true precharge is to be obtained (this position is found when no more oil is expelled).
8. Disconnect the charging equipment and replace the gas valve protective cap and guard.
9. Close the bleed hose valve. Start the engine. Engage "Power Down" and open valve. Allow the suspension to fully raise. Close the valve. Engage "Float" and stop the engine.
10. Open the bleed hose valve and allow the suspension to fully lower.
11. Repeat steps 9 and 10 until oil flows free of air, then remove bleed hose.
12. With suspension fully lowered, measure and take note of dimension "A" (Top of wheel rim to top of fender).
Dimension A (from top of wheel rim to top of fender).
13. Start engine. Open valve. Engage "Power Down" and raise suspension until new dimension "A" is increased by 80 to 90 mm (3.1 to 3.5 in) for a D250E Articulated Truck or by 87 to 97 mm (3.4 to 3.8 in) for a D300E Articulated Truck.
14. Close valve. Engage "Float", and stop the engine.
NOTE: After more than 1 hour of roading, the suspension oil should not be returned to the tank. Used oil is to be bled off into a receptacle.