Product Description
The STARK Expansion tank cap (SKVK-1960003) is an original-equipment-quality pressure-regulating cooling system component engineered by Stark Professional Line. Positioned securely on top of the coolant expansion reservoir, its primary operational function is to seal the cooling loop and maintain a calibrated static pressure of approximately 1.4 to 1.5 bar within the system. Raising the internal pressure elevates the boiling point of the water-antifreeze mixture well past 100°C, allowing the engine to run at high thermal efficiency without localized coolant boiling. The cap houses a twin-valve safety mechanism: a pressure relief valve that releases dangerous pressure spikes to prevent cooling hoses or the radiator from bursting, and a vacuum relief valve that opens as the engine cools to prevent atmospheric pressure from collapsing the hoses. Over time, plastic thermal breakdown, scale build-up, or a fatigued internal spring will cause the valves to stick, resulting in either cooling loop over-pressurization (blown hoses and cracked tanks) or pressure bleed-off (causing premature engine boiling and fluid loss).
Product Specifications
- Manufacturer: STARK Professional Line
- Item Number: SKVK-1960003
- EAN Number: 4059191602179
- Product Condition: New
- Component Classification: Engine Cooling Loop Safety Pressure Cap / Radiator Reservoir Cap
- Material: High-grade composite plastic / polymer
- Colour: Iconic VAG Blue
- Mounting Type: Threaded Screw Connection
- Thread Type: External Thread with an integrated elastomeric sealing ring
- Opening Pressure [bar]: 1.4 - 1.5 (Calibrated to VAG factory cooling loop parameters)
Vehicle Compatibility
This classic blue external-thread pressure cap profile is precision-engineered to service the cooling reservoirs of highly popular front-wheel-drive (FWD) and commercial Volkswagen Audi Group (VAG) platforms stretching from the late 1980s through the late 2000s:
| Car Model / Platform | Compatible Engine Layouts & Codes | Engine Displacement Range | Year of Manufacture |
|---|---|---|---|
| VW Golf Mk2 (19E, 1G1) / Golf Mk3 (1H1) / Golf Mk4 Cabriolet | 1.4 / 1.6 / 1.8 / 2.0 / 1.9 D / 1.9 TD / 1.9 TDI (Classic platforms from standard carburetted lines to early TDIs) |
1272 - 1984 cc | 1988 - 2002 |
| VW Transporter T4 Van / Bus / Platform (70X, 7D) | 1.9 TD / 2.0 / 2.4 D / 2.5 / 2.5 TDI commercial configurations | 1896 - 2461 cc | 1990 - 2003 |
| VW Polo Mk3 (6N1, 6N2) / Polo 86C Coupe / Caddy Mk2 Van | 1.0 / 1.3 / 1.4 / 1.6 / 1.9 SDI / 1.9 TDI variants | 999 - 1896 cc | 1981 - 2002 |
| SEAT Ibiza Mk2 & Mk3 (6K1, 6L1) / Cordoba / Arosa (6H) | 1.0 / 1.4 / 1.4 16V / 1.6 / 1.9 TDI supermini variants | 999 - 1896 cc | 1993 - 2009 |
| VW Passat B3 & B4 (3A2, 35I, 3A5) / Corrado (53I) | 1.6 / 1.8 / 2.0 / 1.9 TD / 2.8 VR6 longitudinal & transverse loops | 1595 - 2792 cc | 1988 - 1997 |
| SEAT Alhambra Mk1 (7M8, 7M9, 7M7) | 1.8 T 20V / 2.0 Petrol & 1.9 TDI MPV engine bays | 1781 - 1984 cc | 1996 - 2010 |
⚠️ Safety, Seal Check & System Bleeding Warning: **NEVER attempt to unscrew the expansion tank cap while the engine is hot or running.** The cooling system is highly pressurized at operating temperature; opening the cap prematurely will induce instantaneous flashing of the coolant into steam, causing explosive boiling that can inflict severe facial and skin burns. Always allow the engine to cool down completely for at least one hour before servicing. When installing the new cap, inspect the internal sealing lip of the plastic reservoir tank for cracks or deformation, as minor imperfections will cause pressure leaks even with a new cap. After replacement, run the engine to operating temperature with your cabin heater set to high to ensure any trapped air bubbles bleed out of the cooling jacket automatically.
Original Equipment Manufacturer (OEM) Reference Numbers
This replacement pressure expansion cap corresponds directly with, or acts as a factory-correct swap for, the following original factory catalogue codes and premium aftermarket entries:
- VAG (VW / AUDI / SEAT / SKODA / PORSCHE): 1H0121321C, 1H0 121 321C, 357121321C, 357 121 321C, 357121321A, 357 121 321A, 1H0121321A, 1H0 121 321A, 357121321, 357 121 321, 1H0121321B, 1H0 121 321B
- RIDEX (Interchange Reference): 56V0004
- FEBI BILSTEIN (Interchange Reference): 02269, 2269, 105933
- GATES (Interchange Reference): RC228
- MEYLE (Interchange Reference): 100 238 0002, 1002380002
- TOPRAN (Interchange Reference): 103 451, 103451