CAMSHAFT 10R8726 - Caterpillar

Visual Checks
A visual inspection of the system is the first step to troubleshoot a problem. Make the inspection with the engine off and the equipment lowered to the ground.1. Check the level of the oil in the transmission.2. Check the magnetic screen for the oil system (on the side of the transmission).3. Remove the filter element and check it for material that would give an indication of damage to a component.4. Inspect all lines and connections for damage or leaks.5. Inspect control linkage for bent, broken or damaged components.Operation Checks
The operation checks can be used to find leakage in the system. They can also be used to find a bad valve or pump. The speed of rod movement when the cylinders move can be used to check the condition of the cylinders and the pump.Lift and lower the tool bar several times.1. Watch the cylinders as they are extended and retracted. Movement must be smooth and regular.2. Listen for noise from the pump.3. Watch the operation of the lift kickout.All of the control levers have detents for the RAISE positions.If there are three control levers, only two of the control levers have FLOAT positions and detents for the FLOAT positions.Tool Bar Circuit Drift
The drift rates will change with different conditions of the hydraulic components as well as with the operation, the hydraulic oil temperature, etc. Before measuring drift on the cylinder rod, the cylinders must be extended three or four times. Check the oil temperature.To check the circuit, lift the tool bar to maximum height and move the control lever to the HOLD position. Measure the distance (and check the time) that the cylinder has retracted. The drift distances in the charts are for new machines. If the cylinder drift is too much:1. Check the make-up valve in the control valve section.2. Check the condition of the valve stem in the control valve section.3. Check the piston seals in the cylinders.Tool Bar Cylinder Travel Time
Operate the tractor to increase the temperature of the oil in the transmission. Extend and retract the rods of the tool bar cylinders again and again to get the warm transmission oil through the hydraulic system. The temperature of the oil must be more than 100° F (37° C) to get accuracy when either a stopwatch or timer is used to measure the cylinder rod travel times.With the engine running at high idle rpm, measure the time for fully retracted cylinder rods to get fully extended when the control lever is moved to RAISE (detent) position. The time for this rod movement (on a new machine) is 4.5 to 5 seconds. The time for the cylinder rods to go from fully extended to fully retracted is approximately .5 second less.If the travel times are not correct:1. Check the pump efficiency.2. Check the setting of the relief valve.3. Check the make-up valve in the control valve section.4. Check the valve stem in the control valve section.5. Check the piston seals in the cylinders.Checking Pump Efficiency
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