OVERVIEW
Genuine VW/Audi Coolant Hose T-Piece Connector
5Q0-121-087-B is the genuine branched connector used in the assigned engine coolant-hose arrangement. Its molded branches join the specified hose connections while preserving the original routing and retention pattern. It is identified in the factory catalog as a T-piece or Y-piece.
One individual coolant connector is supplied per purchased unit, as shown in the original photograph. This is the bare connector, not a complete coolant-hose assembly. The separate hoses, sealing rings, retaining clips, clamps and mounting hardware must be selected for the original vehicle connection.
Technical details
- OEM number: 5Q0-121-087-B / 5Q0121087B.
- Component: Branched coolant-hose connector.
- Catalog names: T-piece, Y-piece and coolant hose connector.
- Design: Molded multi-branch fitting with original hose-end seating and retention profiles.
- Quantity: One connector per purchased unit.
Coolant branches with similar shapes can have different hose diameters, connector profiles and angles. Match the full part number and all mating hose ends before ordering. A nearby connector or a later factory revision must be checked against its own application.
Common reasons to replace
Replace the connector if its body is cracked, a hose seat is damaged, the retaining profile is broken or it no longer supports a sound connection. Age, heat cycling and damage during hose removal can contribute to deterioration of a molded coolant fitting.
Coolant residue, wetness at a branch connection or repeated loss of coolant requires inspection of the fitting, hoses and seals. A damaged hose, worn sealing ring, broken retaining clip or a leak elsewhere in the system requires its own correction. A new connector alone does not repair a defective water pump, thermostat or radiator.
Fitment
The table identifies confirmed engine and body applications with the original connector arrangement. Match the installed hose routing and connector assignment before ordering.
| Vehicle | Model years | Engine | Configuration | Application restrictions |
|---|---|---|---|---|
| Volkswagen Golf | 2015–2018 | 1.8L turbo TSI four-cylinder | Mk7 Hatchback; front-wheel drive; Manual or automatic with original hose arrangement | Original coolant branch connector assigned 5Q0121087B only; match all hose ends and retention arrangement. Not the 2019–2021 1.4L application. One connector supplied; separate hoses, seals and retaining hardware are not included. |
| Volkswagen GTI | 2015–2018 | 2.0L turbo TSI four-cylinder | Mk7 Hatchback; front-wheel drive; 6-speed manual or 6-speed DSG with original hose arrangement | Original coolant branch connector assigned 5Q0121087B only; match all hose ends and retention arrangement. Later years and Golf R are not confirmed by this profile. One connector supplied; separate hoses, seals and retaining hardware are not included. |
| Volkswagen Golf Alltrack | 2017–2019 | 1.8L turbo TSI four-cylinder | Mk7 Wagon; 4Motion; 6-speed manual or 6-speed DSG where offered | Original coolant branch connector assigned 5Q0121087B only; match all hose ends and retention arrangement. Factory Alltrack coolant-hose arrangement only. One connector supplied; separate hoses, seals and retaining hardware are not included. |
| Volkswagen Golf SportWagen | 2015–2019 | 1.8L turbo TSI four-cylinder | Mk7 Wagon; FWD 2015–2018 or 4Motion 2017–2019; Factory manual / automatic / DSG arrangement where offered | Original coolant branch connector assigned 5Q0121087B only; match all hose ends and retention arrangement. 2019 1.8L is 4Motion only. Excludes 2015 TDI and 2019 1.4L FWD. One connector supplied; separate hoses, seals and retaining hardware are not included. |
| Audi A3 | 2015–2016 | 1.8L turbo TFSI four-cylinder; PR TA8 | 8V Sedan; front-wheel drive; 6-speed S tronic with original hose arrangement | Original coolant branch connector assigned 5Q0121087B only; match all hose ends and retention arrangement. Not 2.0L quattro, TDI, S3 or A3 e-tron based on this profile. One connector supplied; separate hoses, seals and retaining hardware are not included. |
| Audi A3 Cabriolet | 2015–2016 | 1.8L turbo TFSI four-cylinder; PR TA8 | 8V Cabriolet; front-wheel drive; 6-speed S tronic with original hose arrangement | Original coolant branch connector assigned 5Q0121087B only; match all hose ends and retention arrangement. Not 2.0L quattro or later Cabriolet engines based on this profile. One connector supplied; separate hoses, seals and retaining hardware are not included. |
Installation and cooling-system service guidance
Follow the vehicle-specific cooling-system procedure and allow the engine to cool before opening the circuit. Relieve pressure and drain the affected portion of the system as prescribed. Keep exposed ports clean while the connector is removed.
Release the original hose connections using the correct method, then inspect the hose ends, sealing rings and retaining hardware. Renew separately specified seals or damaged retention components where required. Install the connector in its original orientation without stressing or twisting the hoses.
Fully seat each connection and verify that its retention mechanism engages. Restore the system using the specified coolant and filling/bleeding procedure. Check the repaired connections for leakage and verify coolant level and normal operation after the prescribed service cycle.
This connector restores the assigned coolant branch. It does not include the surrounding hose assembly or replace other cooling-system components.