GM Service Manual Online
For 1990-2009 cars only

Installation Procedure

Tools Required

J 34730-1A Fuel Pressure Gage

Notice: Clean all of the following areas before performing any disconnections in order to avoid possible contamination in the system:

   • The fuel pipe connections
   • The hose connections
   • The areas surrounding the connections

    Caution: Wrap a shop towel around the fuel pressure connection in order to reduce the risk of fire and personal injury. The towel will absorb any fuel leakage that occurs during the connection of the fuel pressure gage. Place the towel in an approved container when the connection of the fuel pressure gage is complete.


    Object Number: 180378  Size: SH
  1. Remove the cap from the fuel pressure service port connection.
  2. Install the J 34730-1A to the fuel pressure service port located on the fuel rail. Wrap a shop towel around the fitting while connecting the gage to avoid spillage.
  3. Turn the ignition ON, with the engine OFF.
  4. Caution: Do not drain the fuel into an open container. Never store the fuel in an open container due to the possibility of a fire or an explosion.

  5. Place the bleed hose of the fuel pressure gage into an approved gasoline container.
  6. Open the bleed valve on the fuel pressure gage in order to bleed the air from the fuel pressure gage.
  7. Command the fuel pump ON with a scan tool.
  8. Close the bleed valve on the fuel pressure gage.
  9. Inspect for fuel leaks.

Removal Procedure


    Object Number: 180378  Size: SH
  1. Ensure the fuel pump is OFF.
  2. Place the fuel pressure gage bleed hose into an approved container and open the bleed valve in order to bleed off fuel system pressure.
  3. Place a shop towel under the fuel pressure gage in order to catch any remaining fuel spillage.
  4. Remove the fuel pressure gage from the fuel pressure service port.
  5. Drain any fuel remaining in the fuel pressure gage into an approved fuel container.
  6. Inspect for leaks using the following procedure:
  7. 6.1. Turn the ignition ON, with the engine OFF for 2 seconds.
    6.2. Turn the ignition OFF for 10 seconds.
    6.3. Turn the ignition ON, with the engine OFF for 2 seconds.
    6.4. Turn the ignition OFF.
    6.5. Inspect for leaks.
  8. Install the cap on the fuel pressure service port.