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Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine. To prevent possible injury, perform the procedure that follows before testing and adjusting the power train. |
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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. |
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| NOTICE |
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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, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat products. Dispose of all fluids according to local regulations and mandates. |
Specifications
| Charge Relief Valve Pressure | ||
| Date | Equipment ID Code |
|
| Item | Specification | Actual |
| Charge oil pressure (Engine speed 950 ± 25 rpm) | 2800 +400/ -225 kPa (406 +58/ -33psi) 400 kPa (58.01600 psi) |
|
| Charge oil pressure (Engine speed 2100 ± 25 rpm) | 3100 +400/ -300kPa (450 +58/ -44psi) |
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Introduction
This testing procedure will allow the technician to evaluate the pressure setting of the charge oil for the front and rear hydrostatic pumps.
Required Tools
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| Illustration 1 | g02571852 |
Tooling (A) 198-4240 Digital Pressure Indicator Gp | |
| Required Tools | ||||
|---|---|---|---|---|
| Tool | Item | Qty | Part No | Description |
| A | 198-4240 | Digital Pressure Indicator Gp | ||
| A1 | 1 | 198-4234 | Digital Indicator | |
| A2 | 1 | 198-4237 | Pressure Sensor Gp (0 to 3,445 kPa (0 to 500 psi)) |
|
| A3 | 1 | 198-4236 | Adapter Cable As | |
| REQUIRED PARTS LIST | ||
| Part Number | Description | Quantity |
| 215-7697 | Shim Kit | 1 |
Test Preparation - Charge Relief Valve
- Move the machine to a smooth horizontal location.
- Permit only one operator on the machine. Keep all other personnel away from the machine or in the operator sight.
- Place the steering control lever in the NEUTRAL position.
- Engage the parking brake.
- Lower the attachments to the ground.
- Stop the engine.
Test Procedures - Charge Relief Valve
- Open the access door on the left side of the machine.
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| Illustration 2 | g02547160 |
- Connect Tooling (A) to test ports (AA) .
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| Illustration 3 | g02547162 |
- Verify that the implement shutoff control is in the LOCKED position.
- Start the engine and run the engine at LOW IDLE.
- Record the following readings onto the worksheet: engine speed, charge pressure, parking brake pressure and implement system pressure.
- The engine speed should be 950 ± 25 rpm.
- The charge pressure at pressure tap (AA) should be 2800 +400/ -225 kPa (406 +58/ -33psi).
- Increase engine speed to HIGH IDLE.
- Record the charge pressure in the specification table the "Specifications" section.
- The engine speed should be 2100 ± 25 rpm.
- The charge pressure at pressure tap (AA) should be 3100 +400/ -300kPa (450 +58/ -44psi).
- Decrease engine speed to LOW IDLE.
- Stop the engine.
- If the charge pressure is not within specifications, adjust the charge relief valve for that circuit and perform the initial test again.
- Remove the tooling and replace all panels.
Adjustment Procedures - Charge Relief Valve
- Remove floorplate and HVAC ducts.
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| Illustration 4 | g02791691 |
- Loosen locknut (2) and turn set screw (3) clockwise with allen wrench to increase presure. Turn set screw (3) counterclockwise to decrease pressure.
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| Illustration 5 | g02791692 |
(1) Relief valve (2) Locknut (3) Set screw | |