- Engines:
- G3606 (S/N: 3XF)
- G3608 (S/N: 4WF)
- G3612 (S/N: 1YG)
- G3616 (S/N: 4CG)
Description of Change: A new pressure relief valve assembly is used in the Hydrax system. The new pressure relief valve assembly will reduce the level of hydraulic fluid pressure fluctuations at normal operating conditions. High frequency pressure fluctuations can cause premature failure of the 140-9669 Switch (Hydrax system pressure switch). The new pressure relief valve assembly includes a serviceable relief valve. The relief valve in the former pressure relief valve assembly was not available for parts service. The serviceable relief valve can be used to replace the relief valve in the former pressure relief valve assembly.
Adaptable To: The new 176-3586 Relief Valve (pressure relief valve assembly) is a direct replacement for the former 114-9206 Valve (pressure relief valve assembly). The former pressure relief valve assembly is cancelled. The new pressure relief valve assembly includes one 2M-9780 O-Ring Seal and one 5E-4852 Relief Valve. See the illustration.
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| Illustration 1 | g00705644 |
Location of the 2M-9780 O-Ring Seal (2) and5E-4852 Relief Valve (1) in the new 176-3586 Relief Valve (pressure relief valve assembly). | |
The 5E-4852 Relief Valve (1) can also be used to replace the relief valve in the former 114-9206 Valve (pressure relief valve assembly).
Procedure To Install And Adjust The 5E-4852 Relief Valve
The Hydrax system should function properly when the Hydrax system hydraulic pressure is between 1448 to 1724 kPa (210 to 250 psi) at normal operating temperature. When you install the 5E-4852 Relief Valve, the Hydrax system hydraulic pressure should initially be set at 1448 kPa (210 psi). If this pressure is too low, a 456-04 Fault Code can occur at start-up. Increase the pressure setting until the 456-04 Fault Code is eliminated. The Hydrax system should operate normally with the system pressure at 1724 kPa (250 psi) or below 1724 kPa (250 psi).
Note: If the Hydrax system hydraulic pressure must be set higher than 1724 kPa (250 psi) to eliminate the 456-04 Fault Code, there could be a problem with the system pressure gauge or with the 140-9669 Switch (Hydrax system pressure switch). If there is a history of Hydrax system pressure switch failures, install a new 140-9669 Switch (Hydrax system pressure switch) when the 5E-4852 Relief Valve is installed.
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Hot oil and hot components can cause personal injury. Do not allow hot oil or hot components to contact the skin. |
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- Shut down the engine.
- Remove the pressure relief valve from the pressure relief valve housing.
- Install a new 2M-9780 O-Ring Seal on the new 5E-4852 Relief Valve. Install the new relief valve in the pressure relief valve housing.
- Remove the protective cap that is above the pressure setting screw on the new pressure relief valve. Loosen the locknut on the pressure setting screw.
- Install a pressure gauge that can accurately display the Hydrax system hydraulic pressure. The Hydrax system hydraulic pressure should be around 1724 kPa (250 psi).
- Start the engine. Run the engine until the Hydrax system hydraulic fluid is at normal operating temperature.
- Use the pressure setting screw on the new pressure relief valve to adjust the Hydrax system hydraulic pressure to 1448 kPa (210 psi). Shut down the engine.
- Start the engine. If a 456-04 Fault Code is generated, turn the pressure setting screw for one half turn inward. Shut down the engine.
- Repeat Step 8 until the 456-04 Fault Code is eliminated.
- After a successful start, check and document the Hydrax system hydraulic pressure.
- Shut down the engine. Remove the gauge that displayed the Hydrax system hydraulic pressure. Tighten the locknut on the pressure setting screw on the pressure relief valve. Install the protective cap on the pressure setting screw.
- The engine can now be returned to normal operation.