PANEL G 4F6761 - Caterpillar

Lowering And Purging Used Oil From The Suspension System
When the suspension is lowered, clearances are reduced between the axle housing, main frame, tires and fenders which could result in personal injury or death by crushing. Do not enter these areas until the suspension has been fully lowered.
The front suspension must be fully lowered for transportation and servicing purposes. Park the machine in the final position required before lowering the suspension. If the suspension has been lowered to the service position for an extended period (for transporting the machine for example), the piston in the accumulator can stick. This makes setting the ride height difficult. If this occurs, the suspension must be cycled between fully raised and fully lowered to free the piston. Refer to "Cycling the Suspension" in this article. The hydraulic oil in the suspension system must be replaced every 250 service hours or monthly. Purge the oil from the system immediately after the truck has been working and the oil is well mixed.1. Park the machine on hard level ground and put the transmission control into the NEUTRAL position. Engage the parking brake and stop the engine.2. Block both sides of the trailer wheels and disengage the parking brake. The tractor wheels must be allowed to rotate as the suspension lowers.3. Install the steering frame locks.4. Ensure that the shut off valve is closed.On machine numbers (5TN1-830) and (7FN1-449), the shut off valve is located at the position shown in the Operation and Maintenance Manual and in illustration 2.
On machine numbers (5TN831-UP) and (7FN450-UP), the shut off valve is located at the position shown in illustration 1.
Illustration 1.
Location of Shut Off Valve on Machine Numbers (5TN831-UP) and (7FN450-UP) 5. Disconnect the return line from the shut off valve at the location shown in illustration 2 (machine numbers (5TN1-830) and (7FN1-449) or illustration 3 (machine numbers (5TN831-UP) and (7FN450-UP).
Illustration 2. 1. Location of Shut off Valve on Machine Numbers (5TN1-830) and (7FN1-449)2. Location for Disconnecting the Return Line on Machine Numbers (5TN1-830) and (7FN1-449)
Illustration 3.
Location for Disconnecting the Return Line on Machine Numbers (5TN831-UP) and (7FN450-UP) 6. Secure the disconnected line in a suitable waste oil container.7. Lower the suspension by opening the shut off valve. When the suspension is fully lowered, close the shut off valve.8. Re-connect the disconnected line. Ensure that O-Ring seals are in good condition (replace if necessary) and tighten all fittings to the appropriate torque to ensure leak free connections.9. Engage the parking brake.The suspension is now in the service position and used oil has been drained from the suspension