Charge Pressure Relief Setting that is Required with New 174-7573 Pump Group {5058, 5070, 5117, 5117} Caterpillar

Asphalt Paver:

BG-210B (PIN: 9XJ1-274)

Introduction

This Special Instruction provides the information that is necessary in order to set the charge pressure relief setting of the new propel pump.

Setting the Charge Pressure Relief Setting of the Pump

1. Install the new pump in the same position as the old pump and reconnect the hydraulic lines.

2. The charge pressure relief setting of the new pump is at 2100 kPa (305 psi) minus the case pressure at approximately 2340 RPM. The charge pressure relief setting of the old pump is at 1725 kPa (250 psi) minus the case pressure at approximately 2340 RPM. Since the relief settings are different, readjust the relief valve setting of the flushing valve (1) to approximately 200 kPa (30 psi) minus the setting for the propel pump charge pressure. Perform the following steps in order to set the relief valve of the flushing valve (1) .
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   Illustration 1	g00674469

   1. Completely turn in the set screw (1) that is on the flushing valve.
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   Illustration 2	g00674471

   2. Warm the machine up to operating temperature. When the propel lever is in the neutral position, check the charge pressure at port (2) with the engine in high rpm at approximately 2340 RPM.

   3. The relief setting of the flushing valve (1) should be adjusted to approximately 200 kPa (30 psi) below the charge pressure relief setting. This is adjusted by noting the change in the charge pressure when the propel lever is moved from the neutral position to the forward position. Adjust the set screw for the flushing valve until the pressure drops approximately 200 kPa (30 psi) below the charge pressure relief setting when the machine is propelled forward.

      Note: Each full rotation of the set screw will change the relief pressure by approximately 470 kPa (68 psi).