Testing the Case Drain Flow for the Wheel Propel Motor
Introduction
This test is designed to determine the case drain flow from the wheel propel motor.
 |
Escaping fluid under pressure, even a pinhole 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. Always use a board or cardboard when checking for a leak. |
 |
|
Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the work tools have been lowered to the ground, and the oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand. |
|
|
Sudden movement of the machine or release of oil under pressure can cause serious injury to persons on or near the machine. To prevent possible injury, perform the procedure that follows before testing and adjusting the hydraulic system. |
|
| NOTICE |
|---|
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Caterpillar Tools and Shop Products Guide" for tools and supplies suitable to collect and contain fluids on Caterpillar products. Dispose of all fluids according to local regulations and mandates. |
A certain amount of internal leakage is required for lubrication and cooling in the hydraulic motors. Leakage which is higher than the amount that is allowed will reduce the speed of the motor. Leakage will also prevent the motor from developing the maximum torque. All the moving components of the hydraulic motors require lubrication. The moving components can be sealed by the following ways:
- Seals are used.
- Matching high precision machined surfaces.
Internal leakage in a hydraulic motor is measured as the oil leaves the motor through the drain line which is attached to the motor case and the oil returns to the tank.
Required Tools
 | |
| Illustration 1 | g00940624 |
 | |
| Illustration 2 | g00940625 |
Use the tools in Table 1 to complete the following test procedure.
| Required Tools (Standard Tooling) | ||||
|---|---|---|---|---|
| Tool | Item | Part Number | Description | Qty |
| A | A1 | 4C-8689 | Flow meter | 1 |
| A2 | 8C-6874 | Connector | 2 | |
| A3 | 6V-8399 | O-Ring Seal | 2 | |
| A4 | 6V-8942 | O-Ring Reducer | 2 | |
| A5 | 6V-8556 | Nut | 2 | |
| A6 | 6V-8398 | O-Ring Seal | 2 | |
| A7 | 124-2160 | Coupling | 1 | |
| A8 | 124-2114 | Coupling | 1 | |
| A9 | 5P-3413 | Pipe Sealant | 1 | |
| A10 | 122-6889 | Hose | 36 in | |
| B | - | 4C-6500 | Digital Thermometer | 1 |
Note: This procedure must be performed with the machine on jack stands so the tires can rotate.
Note: This test will need to be repeated for each wheel propel motor.
- Make sure that the parking brake is activated. The propel control lever should be in the NEUTRAL position.
- Start the machine and run the engine at 3005 ± 15 RPM for 4 cylinder engines CB-334E (S/N: C4F1-UP, C4X1-UP) and CB-335E (S/N: C5F1-UP). Start the machine and run the engine at 2800 ± 10 RPM for 3 cylinder engines CB-334E (S/N: C4J1-UP) and CB-335E (S/N: C5J1-UP). Check the hydraulic temperature with Tool (B) until the hydraulic oil temperature reaches 38°C (100°F). Stop the engine.
- Disconnect one of the case drain lines (1) from the fitting in the motor.
 | |
| Illustration 3 | g00674234 |
Wheel Propel Motors (1) Case Drain Lines | |
- Connect Tooling (A) between line (1) and the fitting. The direction of flow is from the motor through the flow meter and to the tank.
- Start the machine and run the engine at 3005 ± 15 RPM for 4 cylinder engines CB-334E (S/N: C4F1-UP, C4X1-UP) and CB-335E (S/N: C5F1-UP). Start the machine and run the engine at 2800 ± 10 RPM for 3 cylinder engines CB-334E (S/N: C4J1-UP) and CB-335E (S/N: C5J1-UP).
| NOTICE |
|---|
To prevent overheating of the hydraulic oil and damage to the propulsion system components, do not run each test longer than 30 seconds. |
- With the propel control lever in the NEUTRAL position, read the amount of oil that is flowing through the flow meter. The oil flow should be less than 3.8 L/min (1 US gpm).
- If the flow is not less than 3.8 L/min (1 US gpm), the propel motor will need to be repaired or replaced.
- Release the parking brake.
- Slowly move the propel control lever into the FORWARD position. The oil flow should be less than 3 L/min (0.8 US gpm).
- If the flow is not less than 3 L/min (0.8 US gpm), the propel motor will need to be repaired or replaced.
- Stop the engine and remove tooling (A) and (B). Reconnect case drain line (1) to the fitting in the motor.
- Repeat step 1 through step 11 for the other wheel propel motor.