POT 1C4313 - Caterpillar

Introduction
This procedure should be performed if the measured system pressure is lower than specifications. Step 1. Check system pressure.a. With the engine at low idle, the transmission in neutral, and the parking brake disengaged, check the system pressure at transmission main relief pressure tap (E).
Figure 1: Transmission (15)
(E) Transmission main relief. (L) Transmission Lubrication. (M) Oil temperature. Expected Result: The system pressure is 2925 100 kPa (425 15 psi). Results:* OK - The system pressure is not low. Select a different diagnostic procedure. STOP.* NOT OK - Proceed to Step 2. Step 2. Check transmission modulating valves.a. Check the installation of the transmission modulating valves. Make sure that the valves are installed correctly and torqued properly.b. Repair as required.c. Recheck system pressure using pressure tap (E).
Figure 2: ECPC Clutch Solenoid Valve IdentificationSee Figure 1: Transmission (15) Expected Result: System pressure is 2925 100 kPa(425 15 psi). Results:* OK - STOP.* NOT OK - Proceed to Step 3. Step 3. Check priority valve setting.a. With the engine at low idle, the transmission in neutral and the parking brake disengaged, check the setting on the priority valve using pressure tap (K).
Figure 3: Priority Valve Group (3)
(C) Torque converter inlet. (K) Priority valve. Expected Result: The priority valve setting is 2925 100 kPa(424 15 psi). Results:* OK - Proceed to Step 5.* NOT OK - Proceed to Step 4. Step 4. Inspect priority valve.a. Disassemble and inspect the priority valve for failure.b. Check for problems with the spool, spring, or adjusting mechanism.c. Check operation of machine for original complaint. Expected Result: The original complaint is resolved. Results:* OK - STOP.* NOT OK - Proceed to Step 5. Step 5. Inspect main relief valve.a. Disassemble and inspect main relief valve for failure.b. Check the spring stiffness.c. Repair as required.d. Check operation of machine for original complaint. Expected Result: The original complaint is resolved. Results:* OK - STOP.* NOT OK - Proceed to Step 6. Step 6. Inspect oil pump.a. Disassemble and inspect oil pump for failure.b. Repair as required.c. Check operation of machine for original complaint. Expected Result: The original complaint is resolved. Results:* OK - STOP.* NOT OK - Proceed to Step 7. Step 7. Inspect pump drive.a. Inspect the oil pump drive for failure.b. Repair as required.c. Check operation of machine for original complaint. Expected Result: The original complaint is resolved. Results:* OK - STOP.* NOT OK - Proceed to Step 8. Step 8. Inspect transmission for internal leakage.a. Disassemble and inspect transmission for leaks.b. Check all seals for failure.c. Repair as required. Results:* OK - STOP.* NOT OK - STOP.