Series 50G & 60G Troubleshooting

Section 8.4 Series 50G Recirculation Valve

Section 8.4
Series 50G Recirculation Valve

The turbocharger for the Series 50G coach engine is equipped with an integrally mounted compressor recirculation valve. See Figure "Compressor Recirculation Valve for the Series 50G Engine" . The recirculation valve is designed to prevent or significantly reduce engine air system pressure pulsation and turbocharger surging during engine throttling operations.‪

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 1. Gasket‪

 5. Diaphragm support‪

 2. Diaphragm and piston assembly‪

 6. Screw (3)‪

 3. Cover‪

 7. Compressor housing‪

 4. Spring‪

 ‪

Figure 1. Compressor Recirculation Valve for the Series 50G Engine

Section 8.4.1
Removal of Series 50G Recirculation Valve

Remove the Recirculation Valve for the Series 50G engine as follows:‪

  1. Remove the braided line that connects to the fitting on the top of the recirculation valve cover.
  2. Remove the fitting from the valve cover.
  3. Using a T30-Torx driver, loosen the three screws at the base of the valve cover. While pressing the cover down against the internal spring force, remove and save all three screws.

    Note: Pressing the cover down against the internal spring force will facilitate backing out the three Torx screws.

  4. Slowly release the pressure and let the cover rise up from the base.
  5. Reach below the cover and hold the internal assembly at the plastic diaphragm support. Lift assembly off and turn it over.
  6. Remove the gasket between the cover and the compressor housing. Discard gasket.
  7. Clean the mating cover and compressor housing surfaces of all gasket material or other foreign particles.

Section 8.4.2
Disassembly of Series 50G Recirculation Valve

Disassemble the Recirculation Valve for the Series 50G engine as follows:‪

  1. With the assembly upside down, lift off the diaphragm support and lay it aside.
  2. Inspect the diaphragm for damage and proper seating.
    1. If there are no cracks or tears and the diaphragm is seated properly, go to step 4 .
    2. If there are cracks, tears, or the diaphragm is not seated properly, go to step 3 .
  3. Discard the damaged diaphragm, piston assembly, and a gasket and replace them with the DDC® Recirculation Valve Kit for GT35 Turbocharger.
  4. Lift off the diaphragm and piston assembly.
  5. Clean off any foreign particles from the cover and the spring.
  6. With the cover upside down, insert the spring. Drop the diaphragm and piston assembly over the spring. Place the cleaned diaphragm support over the diaphragm and piston assembly.

    Note: The diaphragm support must squeeze the diaphragm against the upper shoulder in the cover after it is fully assembled and seated against the compressor housing base.

Section 8.4.3
Installation of Series 50G Recirculation Valve

Install the Recirculation Valve for the Series 50G engine as follows:‪

NOTICE:

Both surfaces must be clean and free of any gasket or other foreign particles before a new gasket can be installed during assembly or improper sealing will result.‪

  1. Lightly coat the base of the cover with a non-hardening grease, just enough to hold the new gasket in place on the piston and diaphragm assembly when it is turned over during installation.
  2. Position the gasket so it lines up with the rim of the cover and the three holes.
  3. Hold the assembly loosely together and position it over the mounting base of the compressor housing.
  4. Check for proper orientation and compress the assembly against the spring force. Install the three Torx screws. With continuous pressure on the cover, completely tighten the screws in an easy and even manner to 1.47-1.58 N·m (13-14 lb·in).
  5. After the cover has seated, tighten the screws evenly to 5.9-6.6 N·m (52-58 lb·in).
  6. Lightly coat the fitting threads with sealant. Install fitting in the valve cover.
  7. Attach braided steel line to fitting and tighten to 8.13 N·m (6 lb·ft) of torque.
  8. Once the recirculation valve has been completely checked, replace the Low Pressure Regulator, refer to "8.3.3 Replacing the Throttle for Models 6067–TKG8 and 6047–TKG8" , and follow the Learn Procedure, refer to "8.7 Fuel System Learn Procedure" .


Series 50G and 60G Troubleshooting Guide - 6SE482
Generated on 10-13-2008

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