Audi Audi S4 2016-present Brake System Bolt Torque Specifications
Detailed torque specifications for brake components on the 2016-Present Audi S4 (B9 and B9.5 generations). Includes caliper bolts, rotor bolts, and other relevant hardware.
Important Information
Safety guidelines and reference information for proper torque application
Safety First
- Always verify torque specifications with your vehicle's factory service manual
- Use properly calibrated torque wrenches
- Replace all torque-to-yield (TTY) bolts - they are single-use only
- When in doubt, consult a professional mechanic
Quick Reference Guide
Quick Reference Guide
Common Torque Patterns
Star Pattern
Used for wheels and other circular bolt patterns
Cross Pattern
Used for gaskets and cover plates
Sequential Pattern
Used for head bolts and other critical components
Common Mistakes to Avoid
Common Mistakes to Avoid
Over-tightening
Exceeding the specified torque value can stretch or break fasteners, damage threads, or crack components.
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.
Follow the manufacturer's specified torque sequence pattern.
Dirty Threads
Dirt, rust, or old thread locker can affect torque readings and proper fastener tension.
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.
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.
Check if specs are for dry or lubricated threads. Use specified lubricant when required.
Recommended Tools
Recommended Tools
Torque Wrench (1/4" Drive)
Torque Wrench (3/8" Drive)
Torque Wrench (1/2" Drive)
Angle Gauge
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 components of the front brake system, including calipers, rotors, and related sensors.
1 Front Caliper Mounting Bolts (Brake Carrier to Knuckle)
M14 x 1.5
Front Caliper Mounting Bolts (Brake Carrier to Knuckle)
M14 x 1.5Torque Value
Important Notes
2 Front Caliper Guide Pin Bolts
M10 x 1.25
Front Caliper Guide Pin Bolts
M10 x 1.25Torque Value
Important Notes
3 Front Brake Disc/Rotor Retaining Screw
M6 x 1.0
Front Brake Disc/Rotor Retaining Screw
M6 x 1.0Torque Value
Important Notes
4 Front ABS Wheel Speed Sensor Bolt
M6 x 1.0
Front ABS Wheel Speed Sensor Bolt
M6 x 1.0Torque Value
Important Notes
5 Front Brake Line to Caliper Bolt (Banjo Bolt)
M10 x 1.0
Front Brake Line to Caliper Bolt (Banjo Bolt)
M10 x 1.0Torque Value
Important Notes
Rear Brakes
Torque specifications for components of the rear brake system, including calipers, rotors, parking brake, and related sensors.
1 Rear Caliper Mounting Bolts (Brake Carrier to Knuckle)
M12 x 1.5
Rear Caliper Mounting Bolts (Brake Carrier to Knuckle)
M12 x 1.5Torque Value
Important Notes
2 Rear Caliper Guide Pin Bolts
M10 x 1.25
Rear Caliper Guide Pin Bolts
M10 x 1.25Torque Value
Important Notes
3 Rear Brake Disc/Rotor Retaining Screw
M6 x 1.0
Rear Brake Disc/Rotor Retaining Screw
M6 x 1.0Torque Value
Important Notes
4 Rear ABS Wheel Speed Sensor Bolt
M6 x 1.0
Rear ABS Wheel Speed Sensor Bolt
M6 x 1.0Torque Value
Important Notes
5 Rear Brake Line to Caliper Bolt (Banjo Bolt)
M10 x 1.0
Rear Brake Line to Caliper Bolt (Banjo Bolt)
M10 x 1.0Torque Value
Important Notes
6 Parking Brake Actuator Mounting Bolts
M8 x 1.25
Parking Brake Actuator Mounting Bolts
M8 x 1.25Torque Value
Important Notes
Master Cylinder And Booster
Torque specifications for the brake master cylinder, booster, and fluid reservoir mounting components.
1 Brake Master Cylinder Mounting Bolts
M8 x 1.25
Brake Master Cylinder Mounting Bolts
M8 x 1.25Torque Value
Important Notes
2 Brake Booster Mounting Bolts
M8 x 1.25
Brake Booster Mounting Bolts
M8 x 1.25Torque Value
Important Notes
3 Brake Fluid Reservoir Mounting Bolts
M6 x 1.0
Brake Fluid Reservoir Mounting Bolts
M6 x 1.0Torque Value
Important Notes
Troubleshooting Guide
Common issues, diagnostic steps, and prevention guidelines
Common Issues
Bolt stretching, stripped threads, uneven torque patterns
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
Diagnostic Steps
Visual inspection, torque verification, thread assessment
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
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
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
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 are correct torque specifications important for brake components?
Why are correct torque specifications important for brake components?
Correct torque is critical for brake safety and performance. Over-tightening can damage threads, distort components, and lead to premature failure. Under-tightening can cause fasteners to loosen, resulting in brake failure. For example, an under-torqued caliper bolt could loosen while driving, causing the caliper to detach and resulting in a loss of braking power.
Q2 What happens if I overtighten the brake caliper bolts?
What happens if I overtighten the brake caliper bolts?
Overtightening brake caliper bolts can stretch or break the bolt, damage the threads in the caliper carrier or caliper itself, and potentially crack the caliper or its mounting bracket. This damage may not be immediately visible, leading to future problems. For example, if an overtightened bolt shears internally, it might appear to be holding correctly but can catastrophically fail under braking forces.
Q3 Can I reuse brake caliper bolts?
Can I reuse brake caliper bolts?
It is generally recommended to replace brake caliper bolts each time they are removed. These bolts are often 'torque-to-yield,' meaning they are designed to stretch upon tightening, which limits their reusability. Reusing these bolts could lead to improper torque, which can lead to component failure. It's a good practice to follow the OEM guidelines on bolt replacement during maintenance.
Q4 Do I need to use a torque wrench for brake work?
Do I need to use a torque wrench for brake work?
Yes, using a calibrated torque wrench is essential for ensuring proper torque on brake components. Relying on 'feel' is highly inaccurate and can lead to unsafe conditions. A torque wrench provides a measurement to help meet the manufacturer's specified torque, helping assure that the brakes will be safe for use. Example: Using a simple hand wrench would result in high variability, making an exact torque spec highly improbable.
Q5 What are common signs of brake component issues related to incorrect torque?
What are common signs of brake component issues related to incorrect torque?
Signs of incorrect torque on brake components include unusual noises (clicking, knocking, or squealing), vibrations when braking, or uneven brake wear. If you experience these issues, it's crucial to inspect all fasteners and the components themselves. For example, a clicking noise during braking could indicate a loose caliper or bracket.
Environmental Considerations
Temperature, humidity, and seasonal effects on torque specifications
Temperature Effects
Includes: High Heat, Cold Weather, Thermal Cycling
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
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
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 inch drive)
A calibrated torque wrench is essential for accurately tightening bolts to manufacturer specifications. 1/2 inch drive is recommended for typical brake components.
- Accurate torque settings
- Audible click when torque is reached
Torque Wrench (3/8 inch drive)
A calibrated torque wrench is necessary for smaller fasteners associated with the braking system. 3/8 inch drive is recommended for smaller components such as the brake pad retaining bolts
- Accurate torque settings
- Audible click when torque is reached
Socket Set (Metric)
A comprehensive set of metric sockets is required to fit the various bolt heads found on the brake system. Ensure a deep socket set is available for hard to reach bolts.
- Wide range of sizes
- Durable construction
Socket Extensions
Socket extensions allow access to fasteners that are in recessed or hard-to-reach locations.
- Varying lengths
- Durable construction
Anti-Seize Compound
Use an anti-seize compound on threaded fasteners to prevent galling, corrosion, and to ensure accurate torque readings.
- High-temperature resistance
- Prevents seizing
Service Procedures
Front Brake Caliper Bracket Bolt Torque
Procedure to remove and install the front brake caliper bracket, ensuring proper torque for safe operation.
- Loosen wheel lug bolts.
- Raise vehicle and support on jack stands.
- Remove the wheel.
- Loosen and remove the two caliper bracket bolts.
- Clean the bolt threads with a wire brush.
- Apply a thin layer of anti-seize to the bolt threads.
- Reinstall the caliper bracket and start the bolts by hand
- Torque the caliper bracket bolts to 190Nm + 90 degree angle using a new bolt if recommended by Audi.
- Reinstall the wheel and lower the vehicle.
- Torque the wheel lug bolts to the vehicle specification.
Rear Brake Caliper Bracket Bolt Torque
Procedure to remove and install the rear brake caliper bracket, ensuring proper torque for safe operation.
- Loosen wheel lug bolts.
- Raise vehicle and support on jack stands.
- Remove the wheel.
- Loosen and remove the two caliper bracket bolts.
- Clean the bolt threads with a wire brush.
- Apply a thin layer of anti-seize to the bolt threads.
- Reinstall the caliper bracket and start the bolts by hand
- Torque the caliper bracket bolts to 120Nm + 90 degree angle using a new bolt if recommended by Audi.
- Reinstall the wheel and lower the vehicle.
- Torque the wheel lug bolts to the vehicle specification.
Front Brake Caliper Guide Bolt Torque
Procedure to remove and install the front brake caliper guide bolts, ensuring proper torque for safe operation.
- Loosen wheel lug bolts.
- Raise vehicle and support on jack stands.
- Remove the wheel.
- Loosen and remove the two caliper guide bolts.
- Clean the bolt threads with a wire brush.
- Apply a thin layer of anti-seize to the bolt threads.
- Reinstall the caliper and start the guide bolts by hand
- Torque the caliper guide bolts to 35Nm
- Reinstall the wheel and lower the vehicle.
- Torque the wheel lug bolts to the vehicle specification.
Rear Brake Caliper Guide Bolt Torque
Procedure to remove and install the rear brake caliper guide bolts, ensuring proper torque for safe operation.
- Loosen wheel lug bolts.
- Raise vehicle and support on jack stands.
- Remove the wheel.
- Loosen and remove the two caliper guide bolts.
- Clean the bolt threads with a wire brush.
- Apply a thin layer of anti-seize to the bolt threads.
- Reinstall the caliper and start the guide bolts by hand
- Torque the caliper guide bolts to 35Nm
- Reinstall the wheel and lower the vehicle.
- Torque the wheel lug bolts to the vehicle specification.
Front Brake Rotor Retaining Screw Torque
Procedure to remove and install the front brake rotor retaining screw, ensuring proper torque for safe operation.
- Loosen wheel lug bolts.
- Raise vehicle and support on jack stands.
- Remove the wheel.
- Loosen and remove the brake rotor retaining screw.
- Reinstall the screw and start it by hand.
- Torque the retaining screw to 9Nm
- Reinstall the wheel and lower the vehicle.
- Torque the wheel lug bolts to the vehicle specification.
Rear Brake Rotor Retaining Screw Torque
Procedure to remove and install the rear brake rotor retaining screw, ensuring proper torque for safe operation.
- Loosen wheel lug bolts.
- Raise vehicle and support on jack stands.
- Remove the wheel.
- Loosen and remove the brake rotor retaining screw.
- Reinstall the screw and start it by hand.
- Torque the retaining screw to 9Nm
- Reinstall the wheel and lower the vehicle.
- Torque the wheel lug bolts to the vehicle specification.
Technical Service Bulletins
Brake Judder and Vibration
2018-05-15Some 2016-2018 Audi S4 models may experience brake judder or vibrations during braking. This bulletin outlines potential causes and solutions related to brake component issues.
Resolution: Inspect brake rotors for runout, check caliper guide pins for smooth movement, and replace components as necessary. Ensure proper torque when reassembling the brakes
Brake Noise Diagnosis
2020-11-20This bulletin addresses various noises that may emanate from the brake system in 2019-2020 Audi S4 models, offering diagnosis guidance.
Resolution: Check brake pad wear, ensure proper seating of brake components, inspect for damaged or worn anti-rattle clips and properly torque all brake components.
Updated Caliper Bolt Procedure
2022-03-10This bulletin provides an updated procedure and torque specification for the brake caliper bracket bolts. This update is to reduce the possibility of noise and improve brake functionality.
Resolution: Always use new caliper bolts. Torque the caliper bracket bolts to 190Nm + 90 degree angle for the front axle and 120Nm + 90 degree angle for the rear axle.
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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.
- Vehicle specifications and procedures may vary by model year, trim level, and region.
- Always follow the manufacturer's recommended procedures and safety precautions.
- Working on vehicles can be dangerous. Always take proper safety precautions and use appropriate safety equipment.
- If you're unsure about any procedure, consult a qualified professional mechanic.