SEAL-O-RING 3495726 - Caterpillar

The drift rates can change with different conditions: Some factors include the condition of the hydraulic components, the type of operating conditions, the temperature of the hydraulic oil, etc. Before you measure the circuit drift, the cylinder must be extended at least five times. Measure the drift by using the following probable causes:
Table 9
Circuit Drift of the Ripper    
Oil Temperature    
38° to 49°C (100° to 120°F)    
49° to 66°C (120° to 150°F)     Above
66°C (150°F)    
Minutes until maximum permissible drift of
25 mm (1.0 inch) (machine off the ground)     5.0     2.7     1.7    
Minutes until maximum permissible drift of
9.6 mm (0.38 inch) (ripper off the ground)     5.0     2.7     1.7    Drift Test for Ripper Lift CylindersTEST (A)
Raise the rear of the machine off the ground by lowering the ripper.
Place the ripper control lever in the HOLD position.
Stop the engine.
Watch the ripper lift cylinders and record the movement of the cylinder rods.TEST (B)
Raise the ripper off the ground.
Place the ripper control lever in the HOLD position.
Stop the engine.
Watch the ripper lift cylinders and record the movement of the cylinder rods.
Table 10
Test Results    Probable Causes    
Failed Test (A) only     1. A makeup valve for the head end of the ripper lift cylinders is leaking.    
Failed Test (A) and (B)     1. The cylinder piston seal is leaking.
2. The manual implement lower valve system is leaking.
3. There is excessive wear on the lift stem in the ripper valve.    Note: Remember that an O-ring seal failure in the circuit has the same effect as a major component failure.Ripper Tip (Drift Test)There is no stationary drift test for the ripper tip. If excessive drift is detected during operation, check the following procedure:
A makeup valve for the head end of the ripper lift cylinders is leaking.
The manual implement lower valve system is leaking.
The cylinder piston seal or the bypass valve is leaking.
There is excessive wear on the tip stem in the ripper valve.Note: Remember that an O-ring seal failure in the circuit has the same effect as a major component failure.Pump Efficiency Check
Hydraulic oil pressure can remain in the hydraulic system on this machine after the engine and pump have been stopped. Serious injury can result if this pressure is not released before any service is done on the hydraulic systems. In order to prevent possible injury, release the hydraulic system pressure before working on any fitting, hose, or hydraulic component.Lower all attachments to the ground before service is started. If the hydraulic system must be serviced, tested, or adjusted with the attachment in the raised position, the attachments and lift cylinders must be supported properly.Always move the machine to a location away from the travel of other machines. Be sure that other personnel are not near the machine when the engine is running and tests or adjustments are being made.
This test determines whether a pump is operating within design parameters. Presently, only a bench test is available. The test