TRACK GP 2247737 - Caterpillar

Introduction
Boom RAISE speed is dependent upon the oil flow to the boom cylinders. When boom RAISE is operated alone, both main pump flows are directed to the boom cylinders. The following test will determine whether or not the pumps are developing the correct flows and whether or not the all the flow is being directed to the boom cylinders. Incorrect pump flow or misdirected flow will cause slow boom RAISE. 1. Check boom RAISE speed.Reference: Refer to, "Operational Tests, Cylinder Drift", Form SENR6187 for additional information. Expected Result:Boom RAISE speed should be within the service limit of 4.2 seconds maximum. Results:* OK - STOP.* NOT OK - Proceed to Step 2.2. Perform Control Valve Shift Pressure Test. For further information refer to the section, "Control Valve Shift Pressure Test". Results:* REPAIRED, OK - STOP.* OK - Proceed to Step 3.3. Check that boom drift reduction valve opens completely.a. Place the machine on level ground and stop the engine.b. Release the pressure from the hydraulic system. Refer to "Release Of Pressure Form The Hydraulic System", Form SENR6187.
Main Control Valve
(1) Plug (boom drift reduction check valve).c. Remove plug (1), check valve, and the spring from the drift reduction valve.d. Move the boom pilot control lever to boom RAISE and check the speed.Reference: Refer to, "Cylinder Operating Speed" Form SENR6187 for additional information. Expected Result:The boom RAISE speed is correct (within the 4.2 seconds service limit) only when check valve has been removed. Results:* NOT OK - Boom UP speed still slow with drift reduction check valve removed. Proceed to Step 4.* OK ONLY WITHOUT CHECK - Inspect the drift reduction valve for sticking. Check for restriction in the drain passages of the drift reduction valve. Repair or replace the boom drift reduction valve or the main control valve. STOP.4. Perform Stick II Check Valve Leak Test. For further information refer to the section, "Stick II Check Valve Leak Test". Results:* REPAIRED, OK - STOP.* OK - Proceed to Step 5.5. Perform Stick I Check Valve Leak Test. For further information refer to the section, "Stick I Check Valve Leak Test". Results:* REPAIRED, OK - STOP.* OK - Proceed to Step 6.6. Check the lines between the main control valve and both ends of the boom cylinders for flow restriction.a. Place the machine on level ground and stop the engine.b. Release the pressure from the hydraulic system. Refer to "Release Of Pressure In The Hydraulic System", Form SENR6187.c. Install a 60 000 kPa (8700 psi) gauge into the boom cylinder lines at each line connection.d. Move the boom pilot control lever to boom RAISE position and check the pressure at each connection.A large decrease in pressure between a measured pressure point and the next pressure point indicates the restriction is between those two locations.Reference: Refer to, "Pressure Adjustment, Specifications" Form SENR6187 for additional information. Expected Result:Boom lines are not restricted. Results:* OK - Cause for problem not found with this test. The test equipment may be faulty, a repair may have