GM Service Manual Online
For 1990-2009 cars only

Special Tools

CH-48027 Digital Pressure Gage

Caution: Refer to Gasoline/Gasoline Vapors Caution in the Preface section.

Caution: Relieve the fuel system pressure before servicing fuel system components in order to reduce the risk of fire and personal injury.

After relieving the system pressure, a small amount of fuel may be released when servicing the fuel lines or connections. In order to reduce the chance of personal injury, cover the regulator and the fuel line fittings with a shop towel before disconnecting. This will catch any fuel that may leak out. Place the towel in an approved container when the disconnection is complete.

  1. If necessary, remove the engine cover.
  2. Loosen the fuel filler cap in order to relieve the fuel tank vapor pressure.
  3. Remove fuel rail pipe service port cap.

  4. Object Number: 1828580  Size: SH

    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.

  5. Wrap a towel around the Fuel Rail pipe service port.
  6. Connect CH-48027 (4) to the fuel rail service port.
  7. Connect CH-48027 (2) to CH-48027 (4).
  8. Place the hose of CH-48027 (2) into an suitable gasoline container.
  9. Open the valve on the CH-48027 in order to bleed the Fuel from the Fuel Rail pipe.
  10. Close the valve on the CH-48027 (2).
  11. Remove the hose of CH-48027 (2) from an suitable gasoline container.
  12. 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

    Important: If relieve the fuel pressure in order to install and remove the fuel pressure gage, no further steps are necessary.

  13. Disconnect CH-48027 (2) from CH-48027 (4).
  14. Disconnect CH-48027 (4) from the fuel rail service port.
  15. Remove fuel rail pipe service port around the towel and place into an approved container.
  16. Install fuel rail pipe service port cap.
  17. If necessary, install the engine cover.
  18. Tighten the fuel fill cap.

Without Using CH-48027

    Caution: Gasoline or gasoline vapors are highly flammable. A fire could occur if an ignition source is present. Never drain or store gasoline or diesel fuel in an open container, due to the possibility of fire or explosion. Have a dry chemical (Class B) fire extinguisher nearby.

    Caution: Relieve the fuel system pressure before servicing fuel system components in order to reduce the risk of fire and personal injury.

    After relieving the system pressure, a small amount of fuel may be released when servicing the fuel lines or connections. In order to reduce the chance of personal injury, cover the regulator and the fuel line fittings with a shop towel before disconnecting. This will catch any fuel that may leak out. Place the towel in an approved container when the disconnection is complete.

  1. Loosen the fuel filler cap in order to relieve the fuel tank vapor pressure.
  2. If necessary, remove the engine cover.
  3. Remove fuel rail pipe service port cap.
  4. Wrap a towel around the fuel rail pipe service port, use a small flat-bladed tool in order to depress the fuel test port valve.
  5. Remove fuel rail pipe service port around the towel and place into an approved container.
  6. Install fuel rail pipe service port cap.
  7. If necessary, install the engine cover.
  8. Tighten the fuel fill cap.