Air Conditioning Line / Aluminum Air Conditioning System Tube (AC Line) – 4K1816720AC

Original air conditioning system pressure line (aluminum tube with a flexible section / AC line), designed for Audi A7 Sportback (4K / 4K8 generation) and Audi A6 C8 (type 4K2 / 4K5 / 4KA) vehicles based on the modular longitudinal MLBevo platform.

Original VAG cooling and air conditioning system component. Made of high-quality, seamless aluminum alloy combined with a reinforced, multilayer flexible hose resistant to refrigerants (including R1234yf and R134a) and compressor oils (PAG). It ensures the leak-tight transfer of refrigerant under high operating pressure within the engine compartment air conditioning circuit. Precise profiling and factory-installed vibration dampers protect the line from material fatigue, rubbing against bodywork components, and the formation of leaks.

Technical specifications:

• Original equipment (OE) part number: 4K1816720AC / 4K1 816 720 AC (interchangeable with revisions in the 4K1816720, 4K1816720S, 4K1816720T series)

• System / Category: Heating and air conditioning system (Air Conditioning System / AC Lines)

• Function: Air conditioning refrigerant circuit pressure line (Air Conditioning Refrigerant Hose / Tube)

• Refrigerant compatibility: Designed for systems with R1234yf and R134a refrigerants

• Construction: Formed aluminum tube with a reinforced flexible section and factory-installed flange ends for O-rings

• Installation side: Engine compartment – front / crossmember and bulkhead area

• Steering side:

  Left (LHD – European version, code designation 4K1)

• Condition: Original used part (100% leak-tight, pressure tested, O-ring seats smooth and free of oxidation, mounting threads and flanges in perfect condition, no kinks in the tube, flexible hose with no brittle areas or abrasions)

• Manufacturer: Audi AG / VAG (Original OEM)

Main applications:

• Audi:

  • A7 Sportback (type 4K8) – model years 2018 to 2026 (TFSI and TDI engine versions with left-hand drive, LHD)

  • S7 / RS7 Sportback (type 4K8) – model years 2019 to 2026

  • A6 / A6 Avant / Allroad (type 4K2 / 4K5 / 4KA - C8) – model years 2018 to 2026

  • S6 / RS6 Avant (type 4K - C8) – model years 2019 to 2026

Fitment guarantee and VIN verification

Every air conditioning line undergoes a leak test and inspection of the sealing seats before shipping.

Fitment / installation note: The initial designation 4K1 indicates fitment for left-hand drive (LHD – European version) vehicles. When installing the air conditioning line, it is essential to use new green O-rings designed for the refrigerant and to lubricate them with PAG oil before tightening the flange. Before purchasing, we recommend comparing the full OE number with the index (AC) on the sticker of the old line or verifying fitment using the vehicle's VIN.