CYLINDER GP-LIFT 3805668 - Caterpillar

Troubleshooting for the Signal Resolver Network
Personal injury or death can result from improperly checking for a leak.Always use a board or cardboard when checking for a leak. Escaping air or fluid under pressure, even a pin-hole size leak, can penetrate body tissue causing serious injury, and possible death.If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury.
Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine.To prevent possible injury, perform the procedure that follows before testing and adjusting the hydraulic system.
Table 1
REQUIRED TOOLS    
Part Number     Description     Quantity    
8T-0860     Gauge     1    
6V-3014     Hose Assembly     1    
6V-4143     Coupler     2    
Illustration 2 g00552840
The floorplate has been removed. (1) Signal pressure tap.The signal network can be easily checked. Install one 6V-4143 Coupler Assembly to each end of the 6V-3014 Hose Assembly. Install the 8T-0860 Gauge with a range of 0 to 40000 kPa (0 to 5800 psi). Install 6V-3014 Hose Assembly to signal pressure tap (1) .Start the engine and warm up the hydraulic oil to the operating temperature. Run the engine at LOW IDLE. Operate each control lever in the following order for the 416C, 426C or 436C machines:
Auxiliary (if equipped)
Boom
Swing
Right side stabilizer
Left side stabilizer
Backhoe bucket
Stick
Extendable stick (if equipped)
Auxiliary for the loader (if equipped)
Loader bucket tilt
Lift control for the loader
Priority valveOperate each control lever in the following order for the 428C or the 438C machines:
Boom
Swing
Left side stabilizer
Right side stabilizer
Backhoe bucket
Stick
Extendable stick (if equipped)
Auxiliary for the loader (if equipped)
Loader bucket tilt
Lift control for the loader
Priority valveOperate each of the implements against a load. Watch the gauge. The maximum system pressure of 20700 700 kPa (3000 100 psi) should be reached for most of the circuits. The exceptions are the boom LOWER, the steering circuit and the loader DUMP for parallel lift machines. By using the gauge, small leakage problems such as a cut seal or a missing seal can be detected. Secondary Resolvers with Two or More Valve Sections
If two or more of the control valves in series fail to work properly, the problem may be in the secondary resolver of an upstream implement control valve. The first control valve receives the pump supply oil first. If the secondary resolver for the control valve does not work properly, the secondary resolver may allow signal pressure from any control valve that is further from the pump supply to leak back to the tank.This leakage may be caused by a resolver ball that is not seating or by a resolver ball that is blocking the signal oil to the drain. Signal oil from a downstream control valve may be at a higher pressure than a control valve that is closer to the pump. However, the faulty resolver will not allow the downstream valve to function properly.A leakage in the resolver may be caused by a missing