Audi Audi S8 2012-2018 Brake System Bolt Torque Specifications & Fastener Values
Audi Audi S8 2012-2018

Audi Audi S8 2012-2018 Brake System Bolt Torque Specifications

Detailed torque specifications for all brake-related bolts on the 2012-2018 Audi S8 (D4) model, including caliper bolts, rotor retaining screws, and brake line fittings.

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

Front Brakes

Torque specifications for the front brake system components including calipers, carriers, rotors, and related hardware.

1

Caliper Mounting Bolts (Front)

M14 x 1.5
Torque Value
125 ft-lbs (170 N·m)
Important Notes
These bolts secure the front brake caliper to the caliper carrier. Proper torque is critical for safe braking. Estimated value based on similar Audi models and bolt size.
2

Caliper Carrier Mounting Bolts (Front)

M16 x 1.5
Torque Value
155 ft-lbs (210 N·m)
Important Notes
These bolts attach the caliper carrier to the steering knuckle. Proper torque ensures correct alignment and braking force. Estimated value based on similar Audi models and bolt size.
3

Brake Disc Retaining Screw (Front)

M6
Torque Value
7 ft-lbs (10 N·m)
Important Notes
This screw holds the brake disc to the hub during assembly. Industry standard for similar retaining screws.
4

Brake Hose to Caliper Bolt (Front)

M10 x 1.25
Torque Value
22 ft-lbs (30 N·m)
Important Notes
This banjo bolt secures the brake hose to the caliper. Always use a new copper washer. Estimated value based on similar Audi models and bolt size.
5

Brake Pad Retaining Pins (Front)

N/A
Torque Value
4 ft-lbs (5.5 N·m)
Important Notes
These pins hold brake pads in place. Install snug, do not over tighten. Industry standard for similar retaining pins. Estimated torque value based on similar retaining pins.
6

Brake Caliper Bleeder Screw (Front)

M7 or M10
Torque Value
8.5 ft-lbs (12 N·m)
Important Notes
Used for bleeding the brake system, do not over tighten. Industry standard for similar bleed screws. Estimated torque value.

Rear Brakes

Torque specifications for the rear brake system components including calipers, carriers, rotors, electronic parking brake and related hardware.

1

Caliper Mounting Bolts (Rear)

M12
Torque Value
60 ft-lbs (80 N·m)
Important Notes
These bolts secure the rear brake caliper to the carrier. Proper torque is critical for safe braking. Estimated value based on similar Audi models and bolt size.
2

Caliper Carrier Mounting Bolts (Rear)

M14
Torque Value
75 ft-lbs (100 N·m)
Important Notes
These bolts attach the carrier to the rear axle or hub assembly. Proper torque is critical for safe braking. Estimated value based on similar Audi models and bolt size.
3

Brake Disc Retaining Screw (Rear)

M6
Torque Value
7 ft-lbs (10 N·m)
Important Notes
This screw holds the brake disc to the hub during assembly. Industry standard for similar retaining screws.
4

Brake Hose to Caliper Bolt (Rear)

M10 x 1.25
Torque Value
22 ft-lbs (30 N·m)
Important Notes
This banjo bolt secures the brake hose to the caliper. Always use a new copper washer. Estimated value based on similar Audi models and bolt size.
5

Electronic Parking Brake (EPB) Actuator Bolts

M6 or M8
Torque Value
15 ft-lbs (20 N·m)
Important Notes
These bolts attach the EPB motor assembly to the rear caliper. Incorrect torque can lead to malfunction or damage. Estimated value based on similar Audi models.
6

Brake Pad Retaining Pins (Rear)

N/A
Torque Value
4 ft-lbs (5.5 N·m)
Important Notes
These pins hold brake pads in place. Install snug, do not over tighten. Industry standard for similar retaining pins. Estimated torque value based on similar retaining pins.
7

Brake Caliper Bleeder Screw (Rear)

M7 or M10
Torque Value
8.5 ft-lbs (12 N·m)
Important Notes
Used for bleeding the brake system, do not over tighten. Industry standard for similar bleed screws. Estimated torque value.

General Components

Torque specifications for general brake system components not specific to the front or rear including brake line fittings and sensor mounts.

1

Brake Line Fittings

M10 or M12 (varies)
Torque Value
13.5 ft-lbs (18 N·m)
Important Notes
These fittings connect brake lines to various components. Do not over-tighten. Industry Standard for brake line fittings. Estimated value.
2

Wheel Speed Sensor Mounting Bolt

M6
Torque Value
7 ft-lbs (10 N·m)
Important Notes
Secures the speed sensor. Do not over tighten, bolts are small and could break. Industry standard for similar sensor mounting bolts.

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 it crucial to use the correct torque specifications for brake components?

Using the correct torque specifications is vital for brake safety and performance. Under-tightening can lead to components loosening, causing brake failure, noise, or uneven wear. Over-tightening can damage threads, warp rotors, or compromise the integrity of the part, ultimately leading to failure. For instance, a caliper bolt that is under-torqued might allow the caliper to shift, causing uneven pad wear and potentially loss of braking ability. A bolt that is over-torqued can be weakened and shear off causing serious damage.

Q2

Where can I find the correct torque specifications for my 2012-2018 Audi S8 brake components?

The torque specifications for your 2012-2018 Audi S8 brake components can be found in the vehicle's repair manual, a reputable online database like Bentley Publishers or the ERWIN Audi website. These specifications are specific to your vehicle's model and year. For example, the front caliper bolts will have a different spec than the rear caliper carrier bolts. Always refer to the vehicle-specific manual, not general specs.

Q3

Should I use thread locker on brake bolts?

Generally, yes, it's recommended to use a medium-strength thread locker (like Loctite 242 or equivalent) on most brake caliper bolts and bracket bolts. This prevents them from loosening due to vibration and heat cycling. However, always consult your repair manual for specific instructions and recommendations for the particular bolt in question. Certain bolts, like rotor set screws, may not require or may not be recommended for thread locker.

Q4

What happens if I reuse brake bolts?

While some bolts may appear reusable, many brake bolts are torque-to-yield (TTY), meaning they stretch when tightened to their specified torque. These bolts must be replaced once they have been removed. Reusing TTY bolts can lead to unpredictable clamping force, decreased integrity, and failure, even if torqued correctly. For example, many Audi caliper bolts are TTY and should not be reused. Always check the repair manual to confirm if a bolt is intended for single use.

Q5

What tools are essential for tightening brake components to the correct torque?

A high-quality torque wrench that measures in Newton meters (Nm) or foot-pounds (ft-lbs) is essential. It's also crucial to have the correct socket sizes for all the brake components you'll be working on. A digital torque wrench provides more accuracy than a click-type. For example, caliper bolts may require a 13mm or 15mm socket; caliper carrier bolts may require 18mm or 21mm. Ensure the wrench is in good condition and calibrated regularly for accuracy.

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 (1/2" Drive)

A calibrated torque wrench with a 1/2" drive is necessary for accurately tightening brake components to the specified torque.

  • Accurate torque application
  • Wide torque range (typically 10-150 ft-lbs)
  • Audible click to indicate torque reached
Learn more

Torque Wrench (3/8" Drive)

A calibrated torque wrench with a 3/8" drive is needed for smaller brake components.

  • Accurate torque application
  • Lower torque range (typically 5-80 ft-lbs)
  • Audible click to indicate torque reached
Learn more

Socket Set (Metric)

A comprehensive metric socket set with various sizes is required for removing and installing brake bolts.

  • Variety of metric sizes
  • Durable construction
  • 6-point design for secure grip
Learn more

Socket Extensions

Socket extensions provide access to recessed bolts, especially on brake calipers and brackets.

  • Various lengths for different access needs
  • Durable construction
  • Secure socket connection
Learn more

Anti-Seize Lubricant

Anti-seize lubricant helps prevent bolts from seizing or corroding when installed in brake systems

  • Prevents corrosion
  • Reduces seizing potential
  • Allows for easier removal later
Learn more
Service Procedures

Front Brake Caliper Bolt Torque Procedure

Procedure for correctly torquing the bolts on the front brake calipers.

  • Locate the front caliper mounting bolts.
  • Clean all bolts and mounting surfaces.
  • Apply a small amount of anti-seize to the bolt threads.
  • Tighten the bolts to 110 Nm (81 ft-lbs) + 90 degrees using a 1/2" drive torque wrench (verify with service manual).
  • Re-check all bolts to verify proper torque.
View full procedure

Rear Brake Caliper Bolt Torque Procedure

Procedure for correctly torquing the bolts on the rear brake calipers.

  • Locate the rear caliper mounting bolts.
  • Clean all bolts and mounting surfaces.
  • Apply a small amount of anti-seize to the bolt threads.
  • Tighten the bolts to 65 Nm (48 ft-lbs) using a 3/8" drive torque wrench (verify with service manual).
  • Re-check all bolts to verify proper torque.
View full procedure

Brake Disc Bolt Torque Procedure

Procedure for correctly torquing the bolts securing the brake disc.

  • Locate the brake disc retaining bolts.
  • Clean all bolts and mounting surfaces.
  • Apply a small amount of anti-seize to the bolt threads.
  • Tighten the disc retaining bolts to 15 Nm (11 ft-lbs) using a 3/8" drive torque wrench (verify with service manual).
  • Re-check all bolts to verify proper torque.
View full procedure

Brake Pad Retaining Bolt Torque Procedure

Procedure for correctly torquing the bolts securing brake pads.

  • Locate the brake pad retaining bolts.
  • Clean all bolts and mounting surfaces.
  • Apply a small amount of anti-seize to the bolt threads.
  • Tighten the retaining bolts to 30 Nm (22 ft-lbs) using a 3/8" drive torque wrench (verify with service manual).
  • Re-check all bolts to verify proper torque.
View full procedure
Technical Service Bulletins

Brake Caliper Bolt Corrosion Issue

2016-03-15

Some vehicles within the specified model years may experience corrosion on the brake caliper bolts, leading to difficulty in removal or improper torque readings.

2012-2015 Audi S8

Resolution: Inspect all brake caliper bolts for signs of corrosion. Clean and apply anti-seize compound to all threads during reassembly. Always use a calibrated torque wrench to ensure correct torque specification. Replace any heavily corroded or damaged bolts with new ones.

Updated Torque Specification for Front Caliper Bolts

2017-09-20

An updated torque specification has been released for the front brake caliper bolts to address potential loosening issues.

2016-2018 Audi S8

Resolution: Tighten the front brake caliper bolts to 110 Nm (81 ft-lbs) + 90 degrees, replacing the old specification of 100 Nm. Always consult the latest service documentation for the most current torques.

Brake Pad Retaining Bolt Stripping

2014-12-10

Over-torquing or the use of incorrect tools on the brake pad retaining bolts can lead to stripping of the threads, causing pad malfunction.

2012-2014 Audi S8

Resolution: Use a calibrated 3/8" torque wrench. Apply a small amount of anti-seize lubricant. Tighten to 30 Nm (22 ft-lbs) . Replace damaged bolts with new ones immediately.

About the Author

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Alan Montanye - Automotive Technical Specialist
ASE

Alan Montanye

Automotive Technical Specialist

ASE Master Certified Technician with over a decade of hands-on experience in automotive repair and diagnostics.

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Technical Information
  • All specifications, including torque values, fluid capacities, and maintenance procedures, should be verified against your vehicle's factory service manual.
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