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George H.
George H., ASE Certified Technician
Category: Chevy
Satisfied Customers: 18761
Experience:  GM Tech ASE Master Tech 15+ years
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1989 chevy s10 pickup fuel system- fuel pressure regulator

Customer Question

1989 chevy s10 pickup fuel system- fuel pressure regulator replacement. Do you need to replace fuel meter cover assembly which contains the pressure regulator or can you just replace the regulator? If so is there a special procedure?
Submitted: 8 years ago.
Category: Chevy
Expert:  George H. replied 8 years ago.

Hello I will help you with your question,


You will just replace the diaphragm if it is leaking,





NOTE: To prevent leaks, the pressure regulator diaphragm assembly must be replaced whenever the cover is removed.

WARNING: The pressure regulator contains a large spring under heavy compression. Use care when removing the screws to prevent personal injury.


  1. Remove the four pressure regulator attaching screws, while keeping the pressure regulator compressed.
  2. Remove the pressure regulator cover assembly.
  3. Remove the pressure regulator spring.
  4. Remove the spring seat.
  5. Remove the pressure regulator diaphragm assembly.


Inspect the pressure regulator seat in the fuel meter body cavity for pitting, nicks, or irregularities. (Use a magnifying glass if necessary.) If any of the above is present, the whole fuel body casting must be replaced.


  1. Install a new pressure regulator diaphragm assembly, making sure it is seated in the groove of the fuel meter body.
  2. Install the regulator spring seat and spring into cover assembly.
  3. Install the cover assembly over the diaphragm, while aligning mounting holes. NOTE: Use care while installing the pressure regulator to prevent misalignment of the diaphragm and possible leaks.
  4. Install the four screw assemblies that have been coated with the appropriate thread locking compound, while maintaining pressure on the regulator spring. Tighten the screw assemblies to 2.5 Nm (22.0 lb-in).
  5. With the engine OFF and the ignition ON, check for fuel leaks.


This information is for the 2.5L engine the others are similar. If you need specific info and you do not have the 2.5L please post the engine size


Let me know if you have additional questions


Thank you



George H. and other Chevy Specialists are ready to help you
Customer: replied 8 years ago.

thank you George

three questions,

1- Inspection- replacing the whole fuel body casting? Would that be the pressure regulator cover, spring seat and spring? Or the entire fuel meter cover assembly containing a new pressure regulator?


2-Installation#4-Installing four screws to pressure regulator cover coat with appropriate locking compound? Medium strength- loctite blue OK? High Strength-loctite red OK? Which One? Is the loctite brand ok?


3-I have the 2.8 litre motor is the procedure the same?

Expert:  George H. replied 8 years ago.

Hello, Your reply did not show up in the list of my questions so I am sorry for not replying sooner.


Your 2.8L is serviced differently than the 2.5L. If you are replacing the regulator due to bleedoff after the pump is shutoff be aware that there is a bleed orifice that will allow pressure to reduce after the pump is turned off and this is normal operation.


With that being said your diaphragm is serviced with the fuel meter cover and the regulator is included in the cover








The pressure regulator is a diaphragm-operated relief valve with system operating pressure on one side and and atmospheric pressure on the other side. The function of the regulator is to maintain a constant pressure to the injectors at all times, by controlling the flow in the return line by means of a calibrated bypass.

NOTE: The pressure regulator on this unit is serviced as part of the fuel meter cover and should not be disassembled.



To service the cover




NOTE: The fuel meter cover assembly contains the fuel pressure regulator assembly. The regulator has been adjusted at the factory and should only be serviced as a complete assembly.

WARNING: DO NOT remove the four screws securing the pressure regulator to the fuel meter cover. The fuel pressure regulator includes a large spring under heavy compression which, if accidently released, could cause personal injury. Disassembly might also be result in a fuel leak between the diaphragm and the regulator container.


  1. Disconnect electrical connectors to fuel injectors. (Squeeze plastic tabs and pull straight up).
  2. Remove long and short meter cover screw assemblies.
  3. Remove fuel meter cover assembly. NOTE: DO NOT immerse the fuel meter cover (with pressure regulator) in cleaner, as damage to the regulator and gasket could occur.
  4. Remove fuel meter outlet gasket and pressure regulator seal. Discard old gaskets and seal.


  • Inspect for dirt, foreign material and casting warpage.


  1. Install a new pressure regulator seal, fuel meter outlet passage gasket, and cover gasket.
  2. Install fuel meter cover assembly.
  3. Install attaching screw assemblies, precoated with appropriate locking compound to threads. (Short screws are next to injectors.) Tighten screw assemblies to 3.0 Nm (28.0 lb-in).
  4. Reconnect electrical connectors to fuel injectors.
  5. With engine OFF, and ignition ON, check for leaks around gaskets and fuel line couplings.





The thread locker is blue locktite


Sorry for the delay