Audi A4, S4, RS 4, 8E / B7 (USA)

Brake fluid capacity & service interval

Audi A4, S4, RS 4, 8E / B7 (USA) brake fluid capacity ranges from 1 to 2 liters. Service intervals include checks at 5000 or 10000 miles or 12 months, and changes every 24 months. The data covers 12 configurations.

The configuration chart below lists fill volumes and service intervals for each engine and trim variant.

TypeSpecifications
RS 4 4.2 V8 quattro (309 kW) (2006-2008)
  • Use: Normal
  • Capacity 2 liter
  • Check 10000 miles/ 12 months
  • Change 24 months
RS 4 4.2 V8 quattro (309 kW) (2006-2008)
  • Use: First check only
  • Capacity 2 liter
  • Check 5000 miles/ 12 months
A4 2.0 T (147 kW) (2005-2008)
  • Use: Normal
  • Capacity 1 liter
  • Check 10000 miles/ 12 months
  • Change 24 months
A4 2.0 T (147 kW) (2005-2008)
  • Use: First check only
  • Capacity 1 liter
  • Check 5000 miles/ 12 months
A4 2.0 T quattro (147 kW) (2005-2008)
  • Use: Normal
  • Capacity 1 liter
  • Check 10000 miles/ 12 months
  • Change 24 months
A4 2.0 T quattro (147 kW) (2005-2008)
  • Use: First check only
  • Capacity 1 liter
  • Check 5000 miles/ 12 months
  • Change 24 months
A4 3.2 (188 kW) (2005-2008)
  • Use: Normal
  • Capacity 1 liter
  • Check 10000 miles/ 12 months
  • Change 24 months
A4 3.2 (188 kW) (2005-2008)
  • Use: First check only
  • Capacity 1 liter
  • Check 5000 miles/ 12 months
A4 3.2 quattro (188 kW) (2005-2008)
  • Use: Normal
  • Capacity 1 liter
  • Check 10000 miles/ 12 months
  • Change 24 months
A4 3.2 quattro (188 kW) (2005-2008)
  • Use: First check only
  • Capacity 1 liter
  • Check 5000 miles/ 12 months
S4 4.2 V8 quattro (253 kW) (2005-2008)
  • Use: Normal
  • Capacity 1 liter
  • Check 10000 miles/ 12 months
  • Change 24 months
S4 4.2 V8 quattro (253 kW) (2005-2008)
  • Use: First check only
  • Capacity 1 liter
  • Check 5000 miles/ 12 months

Additional Notes

  • The Audi RS 4 4.2 V8 quattro (309 kW) carries a 2-liter brake fluid capacity for its hydraulic brake system, which is double the 1-liter figure listed for all other configurations in this group. A larger reservoir volume is consistent with the more complex braking hardware found on high-performance variants.
  • All A4, S4, and RS 4 configurations from 2005-2008 share a 24-month brake fluid change interval under normal use conditions. Brake fluid is hygroscopic, meaning it absorbs moisture over time, which lowers its boiling point and reduces braking effectiveness, making time-based replacement a standard practice regardless of mileage.
  • The normal-use check interval across all listed configurations is 10,000 miles or 12 months, whichever comes first. This dual-trigger structure means the interval is governed by both distance and elapsed time.
  • A first-check-only condition is listed separately for each configuration, with an earlier inspection interval of 5,000 miles or 12 months. This initial check is a one-time service event rather than a recurring schedule, intended to assess the brake system after the vehicle's earliest period of use.
  • The A4 2.0 T quattro (147 kW) first-check-only row includes a 24-month change interval, while the equivalent front-wheel-drive A4 2.0 T (147 kW) first-check-only row does not list a change interval. The same pattern appears between the A4 3.2 quattro and A4 3.2 front-wheel-drive configurations.
  • The S4 4.2 V8 quattro (253 kW) and the A4 variants all share the 1-liter brake system capacity despite the S4's significantly higher output engine. The RS 4's larger 2-liter capacity is therefore specific to the RS 4 4.2 V8 quattro (309 kW) and not a general consequence of V8 fitment alone.
  • The RS 4 4.2 V8 quattro's brake system is specifically labeled "hydraulic brake system" in the specifications, whereas all other configurations in the group are labeled simply "brake system." This distinction in nomenclature reflects the RS 4's more elaborate braking setup.

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