LINES GP-AIR 1064352 - Caterpillar

Table 1
Required Tools    
Part Number     Description     Qty    
6V-9511     Face Seal Plug     1    
6V-9746     O-Ring Seal     1    
6V-9832     ORFS Cap     1    An initial test for lift cylinder drift should be done before you isolate the lift cylinders.Reference: Testing and Adjusting, "Lift and Tilt Cylinder Drift - Check"This test will help to determine whether one of the lift cylinders is causing a drift problem. When the oil port at the end of the lift cylinder is blocked, the lift cylinder should not move during a drift test. If the lift cylinder moves, there is internal leakage in one of the lift cylinders. If both cylinders are not drifting then there is probably a problem in the main control valve.
Engage the parking brake.
Install the steering frame lock.
Start the engine. Raise the lift arms until the work tool is approximately 1 m (3.3 ft) off the ground and the work tool is parallel to the ground. Position support blocks under the work tool. Lower the work tool onto the support block.
Turn the engine start switch to the OFF position.
When the engine is no longer running, turn the key start switch to the ON position. Move the hydraulic control levers to all positions in order to release the pressure in the hydraulic system. Place the lift control lever in the HOLD position.
Push in the plunger for the breaker relief valve in order to relieve the pressure in the hydraulic tank. Push down on the plunger until all pressure is released from the hydraulic tank.
Release all hydraulic pressure before any fitting, any hose, or any component is loosened, tightened, removed, or adjusted.Reference: Refer to the Service Manual module Testing and Adjusting, "System Pressure - Release".
Illustration 1 g00840875
Hose Assemblies for the Lift Cylinders (Head End)
The hose assemblies are located in the front loader frame. Remove the loader tower access panel from the front frame. Remove hose assembly (1) from the main control valve. This will allow you to test the lift cylinder on the right side of the machine. Install a 6V-9511 Face Seal Plug with 6V-9746 O-Ring Seal in the hose that is connected to the head end of the lift cylinder. Install a 6V-9832 ORFS Cap on the adapter in the main control valve.
Start the engine. Tilt the work tool to the full TILTBACK position. This will remove the work tool from the support blocks. Remove the support blocks.
Turn the engine start switch to the OFF position. Leave the lift arms in this position. Place the lift lever in the full LOWER position. Record the amount of rod movement of that lift cylinder. Refer to Table 2 for the maximum amount of drift for the temperature of the hydraulic oil.
Table 2
Approximate Lift Cylinder Drift (1)    
Oil Temperature     Maximum Drift     Time    
38° to 49°C (100° to 121°F)    
13.0 mm (.51 inch)     5.0 minutes    
50° to 65°C (122° to