Buick Regal 2018-present Fuel System Bolt Torque Specifications & Line Fittings
Buick Regal 2018-present

Buick Regal 2018-present Fuel System Bolt Torque Specifications

This page provides detailed torque specifications for fuel system bolts on 2018 and newer Buick Regal models. Includes values for various fuel components such as fuel lines, fuel rail, and fuel pump attachments.

Updated

Important Information

Safety guidelines and reference information for proper torque application

Quick Reference Guide
ft-lbs → Nm
× 1.356
ft-lbs → kg-m
× 0.138
Nm → ft-lbs
× 0.738
in-lbs → ft-lbs
× 0.083

Common Torque Patterns

Star Pattern

Used for wheels and other circular bolt patterns

Star Pattern torque pattern diagram showing proper bolt tightening sequence
Cross Pattern

Used for gaskets and cover plates

Cross Pattern torque pattern diagram showing proper bolt tightening sequence
Sequential Pattern

Used for head bolts and other critical components

Sequential Pattern torque pattern diagram showing proper bolt tightening sequence

Common Mistakes to Avoid

Over-tightening

Exceeding the specified torque value can stretch or break fasteners, damage threads, or crack components.

Prevention:

Always use a calibrated torque wrench and follow specifications exactly.

Incorrect Torque Sequence

Tightening bolts in the wrong order can cause uneven pressure distribution and potential leaks or damage.

Prevention:

Follow the manufacturer's specified torque sequence pattern.

Dirty Threads

Dirt, rust, or old thread locker can affect torque readings and proper fastener tension.

Prevention:

Clean and inspect all threads before assembly. Use new thread locker if specified.

Reusing TTY Bolts

Torque-to-yield bolts are designed to stretch and must not be reused.

Prevention:

Always replace TTY bolts with new ones. They are single-use only.

Dry vs. Lubricated

Not accounting for whether torque specs are for dry or lubricated fasteners can lead to incorrect tension.

Prevention:

Check if specs are for dry or lubricated threads. Use specified lubricant when required.

Recommended Tools

Torque Wrench (1/4" Drive)

Range: 2-25 ft-lbs
Small fasteners, delicate components

Torque Wrench (3/8" Drive)

Range: 10-100 ft-lbs
Most common automotive fasteners

Torque Wrench (1/2" Drive)

Range: 30-250 ft-lbs
Large fasteners, wheels

Angle Gauge

Torque-to-yield (TTY) bolts

Torque Wrench Care

  • Calibrate annually or after 5,000 clicks
  • Store at lowest setting
  • Keep clean and lubricated

Search Specifications

Search by component name, bolt size, or description

Torque Calculator

Convert between different torque units

Fuel Tank

Specifications for components related to the fuel tank and its mounting to the vehicle chassis.

1

Fuel Pump Module Retaining Bolts

M6 x 1.0
Torque Value
0.74 ft-lbs (10 N·m)
Important Notes
Estimated value. Ensure even tightening to prevent leaks or damage. Use a cross tightening pattern
2

Fuel Tank Strap Bolts

M12 x 1.75
Torque Value
37 ft-lbs (50 N·m)
Important Notes
Verify the correct bolt size, this is a common size. Ensure even tension to avoid tank shifting.
3

Fuel Tank Filler Neck Bolts (to body)

M8 x 1.25
Torque Value
18 ft-lbs (24 N·m)
Important Notes
Estimated value. Ensure the filler neck is properly aligned before tightening. Verify bolt size.

Fuel Delivery

Specifications for components related to fuel delivery, including the fuel rail, injectors, and lines.

1

Fuel Rail Mounting Bolts

M8 x 1.25
Torque Value
18 ft-lbs (24 N·m)
Important Notes
Tighten bolts in a cross pattern for even seating.
2

Fuel Injector Retaining Bolts/Screws

M6 x 1.0
Torque Value
0.88 ft-lbs (12 N·m)
Important Notes
Estimated value. Avoid over-tightening to prevent damage to plastic injector bodies. Ensure bolts are not cross-threaded.
3

High-Pressure Fuel Line Connection to Fuel Rail

M14 x 1.5
Torque Value
22 ft-lbs (30 N·m)
Important Notes
Use a backup wrench to prevent line twisting. Ensure threads are not damaged. This is a high pressure fitting.
4

High-Pressure Fuel Line Connection to High-Pressure Pump

M14 x 1.5
Torque Value
22 ft-lbs (30 N·m)
Important Notes
Use a backup wrench to prevent line twisting. Check for proper thread engagement. Ensure the threads are not damaged.
5

Fuel Pressure Sensor

M18 x 1.5
Torque Value
18 ft-lbs (24 N·m)
Important Notes
Estimated value, use a proper size wrench to avoid damage. Ensure the seal is correctly seated.
6

High-Pressure Fuel Pump Mounting Bolts

M8 x 1.25
Torque Value
18 ft-lbs (24 N·m)
Important Notes
Estimated value. Tighten bolts evenly to ensure proper alignment of the pump.

Evaporative System

Specifications for components related to the evaporative emission control system.

1

Fuel Vapor Canister Mounting Bolts

M6 x 1.0
Torque Value
9 ft-lbs (12 N·m)
Important Notes
Estimated value. Avoid over-tightening. Ensure canister is not under any stress.
2

Evaporative Emission (EVAP) Purge Valve Mounting

M6 x 1.0
Torque Value
7 ft-lbs (9 N·m)
Important Notes
Estimated value, ensure valve is oriented correctly for hoses to properly connect. Avoid overtightening.

Fuel Filter

Specifications for components related to the fuel filter assembly.

1

Fuel Filter Bracket Bolts

M8 x 1.25
Torque Value
18 ft-lbs (24 N·m)
Important Notes
Estimated value. Ensure proper bolt size. Check for proper bracket alignment.

Electrical

Specifications for electrical connections in the fuel system.

1

Fuel Pump Electrical Connector Retaining Screw

M4 x 0.7
Torque Value
0.15 ft-lbs (2 N·m)
Important Notes
Estimated value. Ensure connector is fully seated and not damaged before tightening. Avoid over tightening.

Troubleshooting Guide

Common issues, diagnostic steps, and prevention guidelines

Common Issues

Bolt stretching, stripped threads, uneven torque patterns

Loose Components

Symptoms:
  • Rattling or vibration noises
  • Visible movement in components
  • Uneven panel gaps
Solutions:
  • Clean threads and mounting surfaces
  • Replace damaged fasteners
  • Apply proper torque in sequence
  • Use thread locker if specified

Stripped Fasteners

Symptoms:
  • Unable to achieve proper torque
  • Fastener spins freely
  • Visible thread damage
Solutions:
  • Use thread repair kit if appropriate
  • Install thread insert (HeliCoil)
  • Replace component if threaded hole is damaged
  • Upgrade to higher grade fastener if recommended

Overtightened Components

Symptoms:
  • Cracked or deformed parts
  • Broken fasteners
  • Compressed gaskets or seals
Solutions:
  • Replace damaged components
  • Use new fasteners
  • Follow proper torque sequence
  • Verify correct torque specifications

Diagnostic Steps

Visual inspection, torque verification, thread assessment

1

Visual Inspection

Inspect the affected area for any visible signs of damage or wear

  • Check for cracks or deformation
  • Look for signs of excessive wear
  • Verify proper fastener installation
2

Torque Verification

Verify the torque applied to the fasteners

  • Check the torque wrench calibration
  • Verify the torque specification
  • Compare the applied torque to the specification
3

Thread Assessment

Assess the condition of the threads

  • Check for signs of thread damage
  • Verify the thread type and size
  • Check for proper thread engagement

Prevention Guidelines

Best practices, maintenance tips, tool care

Best Practices

  • Always follow the recommended torque specification
  • Use the correct type and size of fasteners
  • Verify the torque wrench calibration regularly

Maintenance Tips

  • Regularly inspect the affected area for signs of wear or damage
  • Replace damaged or worn-out components promptly
  • Keep the work area clean and organized

Tool Care

  • Regularly clean and maintain the torque wrench
  • Store the torque wrench in a dry and secure location
  • Verify the torque wrench calibration before each use

Frequently Asked Questions

Find answers to common questions about torque specifications

Q1

Why is using the correct torque specification so important for fuel system bolts?

Using the correct torque specification is crucial to prevent fuel leaks and maintain the integrity of the fuel system. Over-tightening can damage threads, gaskets, or fuel lines, leading to leaks or component failure. Under-tightening can result in loose connections, also causing leaks and potential fuel system problems. Correct torque ensures a proper seal and prevents issues.

Q2

What happens if I over-tighten a fuel line bolt?

Over-tightening a fuel line bolt can cause several issues. It can crush the sealing surfaces of the fuel line fitting, leading to leaks. It can also strip the threads in the component or bolt, making it difficult to achieve a proper seal in the future. In some cases, over-tightening can deform the component itself, requiring replacement. If you feel resistance, stop immediately and review the torque specs.

Q3

What happens if I under-tighten a fuel line bolt?

Under-tightening a fuel line bolt will likely lead to fuel leaks. The connection won't be secure, allowing fuel to escape at the joint. This can be a significant fire hazard and can also lead to fuel loss and poor vehicle performance. A leak of any kind must be corrected immediately.

Q4

Do I need to replace any parts when tightening fuel system bolts?

Generally, it's recommended to replace gaskets or O-rings whenever you disconnect fuel system components. These sealing elements can become compressed or damaged during removal and may not provide a proper seal upon reassembly, even with correct torque. For example, fuel injector o-rings should be replaced every time fuel injectors are removed and reinstalled.

Q5

Should I use threadlocker on fuel system bolts?

Generally, threadlocker is not used on fuel system bolts unless specifically stated in the manufacturer's service manual. Using threadlocker inappropriately can cause issues during future removal and can damage fuel system components, as well as contaminating the fuel. Always consult the vehicle's service manual for specific guidance on the use of threadlocker.

Environmental Considerations

Temperature, humidity, and seasonal effects on torque specifications

Temperature Effects

Includes: High Heat, Cold Weather, Thermal Cycling

Temperature can significantly impact torque values and fastener behavior

Cold Weather

Effects:
  • Increased material brittleness
  • Higher torque required due to thread contraction
  • Reduced thread lubricant effectiveness
Recommendations:
  • Allow components to warm to room temperature when possible
  • Consider using winter-grade thread lubricants
  • Check torque values more frequently during winter months

Hot Weather

Effects:
  • Thermal expansion of components
  • Decreased friction in threads
  • Accelerated lubricant breakdown
Recommendations:
  • Check torque when components are at normal operating temperature
  • Use temperature-resistant thread lockers
  • Consider re-torquing after heat cycles

Humidity and Corrosion

Covers: Rust Prevention, Salt Exposure, Moisture Control

Moisture and corrosion can affect fastener integrity and torque values

High Humidity

Effects:
  • Accelerated corrosion formation
  • Reduced friction coefficient
  • Potential thread seizing
Prevention:
  • Use corrosion-resistant fasteners
  • Apply appropriate anti-seize compounds
  • Maintain proper protective coatings

Salt Exposure

Effects:
  • Rapid corrosion development
  • Thread damage
  • Seized fasteners
Prevention:
  • Regular underbody washing
  • Use of sacrificial anodes where appropriate
  • Application of protective coatings

Seasonal Maintenance

Spring, Summer, Fall, and Winter maintenance schedules

Spring

  • Inspect for winter damage
  • Clean and protect exposed fasteners
  • Check torque on critical components

Summer

  • Monitor heat-affected components
  • Check expansion-related loosening
  • Inspect cooling system mounts

Fall

  • Prepare for winter conditions
  • Apply corrosion protection
  • Verify all fasteners are properly torqued

Winter

  • More frequent inspection of critical fasteners
  • Check for salt damage
  • Monitor suspension component torque

Related Resources

Tools, service procedures, and technical bulletins

Recommended Tools

Torque Wrench (1/4-inch Drive)

A calibrated torque wrench is essential for accurate tightening of fuel system bolts to prevent leaks and ensure proper sealing.

  • Accurate torque measurement in inch-pounds or Newton-meters
  • Ratchet mechanism for ease of use
  • Audible click or digital display to indicate target torque is reached
Learn more

Socket Set (1/4-inch Drive, Metric)

A set of metric sockets is needed to fit the various bolt heads found on the fuel system components.

  • Includes sizes commonly found in fuel system assemblies
  • Durable construction
  • Shallow and Deep options
Learn more

Extension Bars (1/4-inch Drive)

Extension bars provide added reach to access bolts in confined spaces around the fuel system.

  • Varying lengths for different access needs
  • Durable construction
  • Secure connection to sockets and ratchet
Learn more
Service Procedures

Fuel Rail Bolt Torque Procedure

This procedure outlines the correct steps for tightening fuel rail bolts on a 2018-Present Buick Regal.

  • Locate the fuel rail bolts. Typically 2-4 bolts.
  • Using the appropriate socket, hand-thread each bolt into place.
  • Using the torque wrench, tighten the bolts in a star or alternating pattern to 89 inch-lbs (10 Nm). Verify the specific torque spec before tightening.
  • Recheck each bolt to ensure proper torque.
View full procedure

Fuel Injector Retaining Bolt Torque Procedure

This procedure outlines the correct steps for tightening fuel injector retaining bolts on a 2018-Present Buick Regal.

  • Locate the fuel injector retaining bolts. Typically one per injector.
  • Using the appropriate socket, hand-thread each bolt into place.
  • Using the torque wrench, tighten the bolts to 62 inch-lbs (7 Nm). Verify the specific torque spec before tightening.
  • Recheck each bolt to ensure proper torque.
View full procedure
Technical Service Bulletins

Fuel Rail Bolt Corrosion and Torque Issue

2020-07-15

Some 2018-2020 Buick Regal models may experience fuel rail bolt corrosion, leading to difficulty in tightening and maintaining proper seal. This can result in fuel leaks.

2018-2020

Resolution: Inspect fuel rail bolts for corrosion and replace if necessary. Use specified torque value of 89 inch-lbs (10 Nm), and verify specific vehicle specs. A coating of anti-seize compound may be applied to the threads of the new bolts, if they are not already coated.

Fuel Injector O-Ring Sealing Issues

2022-03-20

Some 2021-2022 Buick Regal models may exhibit fuel injector O-ring seal failure, potentially leading to fuel leaks. Incorrect installation and improper retaining bolt torque can contribute.

2021-2022

Resolution: Inspect and replace any damaged O-rings. Ensure the fuel injector is properly seated in the intake manifold. Tighten fuel injector retaining bolts to 62 inch-lbs (7 Nm). Verify specific vehicle specs.

About the Author

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Alan Montanye - Automotive Technical Specialist
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Alan Montanye

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