HOSE AS 1842401 - Caterpillar

Table 1
Tools Needed Qty
6V-3079 Pressure Hose Assembly 1
6V-4143 Coupler Assembly 2
8T-0855 Pressure Gauge ( 4000 kPa (580 psi)) 1 Note: Make sure that the filters and the screens are clean before you test any pressures. Make sure that the oil is at operating temperature before you perform this test.
Personal injury or death can result from sudden machine movement.Sudden movement of the machine or release of air pressure or oil pressure can cause injury to persons on or near the machine.To help prevent possible injury before testing and adjusting any air system or hydraulic system, perform the procedure in the Testing and Adjusting, "General Information" section.
This test will show the following conditions if the conditions exist:
The maximum lockup pressure is correct.
The operation of the modulation reduction valve is correct.Procedure
Disconnect the electrical harness from the lockup clutch solenoid. Disconnect the upshift solenoid and the downshift solenoid.
The transmission control must be in NEUTRAL and the transmission rotary selector spool must be in NEUTRAL.
The downshift solenoid remains activated while the transmission is in NEUTRAL. This causes +24 volts to be supplied to the electrical harness for the downshift solenoid.
Use two Sure-Seal 2-pin connectors and two 16 gauge wires in order to make a jumper harness. The two wires should be approximately 4.5 m (15 ft) long. Connect one end of the jumper harness to the harness for the downshift solenoid.
Illustration 1 g00525444
(A) Pressure tap for the lockup clutch pressure "LU"
Use a coupler and a hose to connect a 8T-0855 Pressure Gauge ( 4000 kPa (580 psi)) to the nipple at pressure tap (A).
Start the engine while the parking brake is activated. Run the engine at the low idle rpm with the transmission in NEUTRAL. The pressure on the gauge must be 0 kPa (0 psi).
Look at the pressure gauge. Connect the jumper harness from the downshift solenoid to the lockup clutch solenoid. Run the engine at medium idle. Medium idle is approximately 1300 rpm. The pressure on the gauge must be 2065 70 kPa (300 10 psi).
Disconnect the jumper harness from the lockup clutch solenoid. The pressure on the gauge must be 0 kPa (0 psi).
Stop the engine. After the pressure is correctly set, remove the test equipment.
Illustration 2 g00525482
Synchronizing valve
(1) Selector piston
(2) Load piston
(3) Load piston plug
(4) Inner spring
(5) Outer spring
(6) Load piston orifice
(7) Shuttle valve
(8) Spring Problem: The oil pressure is not 0 kPa (0 psi) when the lockup clutch solenoid is deactivated.
Probable Cause
Selector piston (1) is stuck.
Spring (8) is weak or broken.
Shuttle valve (7) is stuck.
The lockup clutch solenoid is bad. Perform the Testing and Adjusting, "Solenoid Valve - Test".Problem: The oil pressure is 0 kPa (0 psi) with the lockup clutch solenoid activated.
Probable Cause
There is either a small amount of pilot oil or no pilot oil. Perform the test in the Testing and Adjusting, "Torque Converter Lockup Clutch Pilot Pressure - Test and Adjust".
Incorrect operation of shuttle valve (7)
Outer spring (5) is weak or broken and/or inner spring (4) is weak or broken.Problem: The oil pressure is