{"product_id":"vw-coolant-expansion-tank-cap-103643","title":"TOPRAN 103 643 Expansion tank cap VW","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003eTOPRAN Expansion tank cap (103 643)\u003c\/strong\u003e is an original-equipment-quality replacement pressure-control valve seal designed for the engine cooling matrix. Positioned directly onto the coolant expansion tank reservoir, this cap regulates the internal thermal expansion of the engine's coolant. By holding a calibrated atmospheric layout pressure, it raises the boiling point of the water-glycol fluid mix to protect the engine against overheating during prolonged operation. In the event of extreme thermal spikes, its integrated mechanical safety spring valve vents excessive gas layout pressure safely away from the engine bay.\u003c\/p\u003e\n\n\u003ch3\u003eProduct Specifications\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer:\u003c\/strong\u003e TOPRAN\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eItem Number:\u003c\/strong\u003e 103 643\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEAN Number:\u003c\/strong\u003e 1213230000019\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eProduct Condition:\u003c\/strong\u003e New\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eColour:\u003c\/strong\u003e Blue \u003cem\u003e(Modern technical upgrade over legacy black versions)\u003c\/em\u003e\n\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e High-grade structural polyamide plastic\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMounting Type:\u003c\/strong\u003e Threaded Screw Connection\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThread Type:\u003c\/strong\u003e Internal Thread\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOpening Pressure Rating:\u003c\/strong\u003e 1.2 to 1.3 bar\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSupplementary Information:\u003c\/strong\u003e Equipped pre-installed with an integrated rubber sealing O-ring gasket\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eVehicle Compatibility\u003c\/h3\u003e\n\u003cp\u003eThis universal M45-threaded blue relief cap accommodates an expansive lineage of classic and modern-classic Volkswagen Group (VAG) platforms stretching across the late 1970s up to the early 2000s:\u003c\/p\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\n    \u003ctr style=\"background-color: #f2f2f2;\"\u003e\n      \u003cth\u003eCar Model\u003c\/th\u003e\n      \u003cth\u003eCompatible Engines \/ Variants\u003c\/th\u003e\n      \u003cth\u003eEngine Power (hp \/ kW)\u003c\/th\u003e\n      \u003cth\u003eYear of Manufacture\u003c\/th\u003e\n    \u003c\/tr\u003e\n  \u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eVW Golf II (19E, 1G1) \/ Jetta II (19E)\u003c\/td\u003e\n      \u003ctd\u003e1.0 \/ 1.3 \/ 1.6 \/ 1.6 D \/ 1.6 TD \/ 1.8 \/ 1.8 GTI \/ 1.8 GTI 16V\u003c\/td\u003e\n      \u003ctd\u003e45 - 139 hp \/ 33 - 102 kW\u003c\/td\u003e\n      \u003ctd\u003e1983 - 1992\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eAudi 80 (B2, B3, B4) \/ 100 (C3, C4)\u003c\/td\u003e\n      \u003ctd\u003e1.6 \/ 1.8 \/ 1.9 TD \/ 1.9 TDI \/ 2.0 \/ 2.3 \/ 2.6 \/ 2.8 V6\u003c\/td\u003e\n      \u003ctd\u003e70 - 174 hp \/ 51 - 128 kW\u003c\/td\u003e\n      \u003ctd\u003e1978 - 1996\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eAudi A4 B5 (8D2, 8D5) \/ A6 C4 (4A2, 4A5)\u003c\/td\u003e\n      \u003ctd\u003e1.6 \/ 1.8 \/ 1.8 T \/ 1.9 TDI \/ 2.4 \/ 2.6 \/ 2.8\u003c\/td\u003e\n      \u003ctd\u003e90 - 193 hp \/ 66 - 142 kW\u003c\/td\u003e\n      \u003ctd\u003e1994 - 2001\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eAudi A8 (4D2, 4D8)\u003c\/td\u003e\n      \u003ctd\u003e2.8 V6 \/ 2.8 V6 quattro (Early configurations)\u003c\/td\u003e\n      \u003ctd\u003e163 - 193 hp \/ 120 - 142 kW\u003c\/td\u003e\n      \u003ctd\u003e1994 - 2002\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eVW Golf I (17) \/ Polo (86C) \/ LT 35\u003c\/td\u003e\n      \u003ctd\u003e1.1 \/ 1.3 \/ 1.5 \/ 1.6 GTI \/ 2.4 D \/ 2.4 TD\u003c\/td\u003e\n      \u003ctd\u003e40 - 110 hp \/ 29 - 81 kW\u003c\/td\u003e\n      \u003ctd\u003e1974 - 1996\u003c\/td\u003e\n    \u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cblockquote\u003e⚠️ \u003cstrong\u003eCritical Technical Evolution Note:\u003c\/strong\u003e Early classic VAG models originally shipped from the factory with a **black expansion tank cap** rated at a lower relief pressure. This **blue structural cap** is the official factory supersede update designed to replace those obsolete black components. It features a superior, modernized relief valve mechanism that prevents early coolant vaporization and splitting failure profiles common on aging round expansion spheres. Always ensure your expansion tank neck matches the screw-type internal thread style.\u003c\/blockquote\u003e\n\n\u003ch3\u003eOriginal Equipment Manufacturer (OEM) Reference Numbers\u003c\/h3\u003e\n\u003cp\u003eThis premium expansion reservoir cap serves as a direct cross-reference for the following catalog original production part codes:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eVAG (VW \/ AUDI \/ SEAT \/ SKODA):\u003c\/strong\u003e 443 121 321, 443121321, 171 121 321, 171121321, 171 121 321B, 171121321B, 171 121 321D, 171121321D, 171 121 321F, 171121321F\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"topran","offers":[{"title":"Default Title","offer_id":57537990787455,"sku":"103643","price":4.0,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1005\/7252\/9023\/files\/thumb_b47364c6-917f-4204-8ac5-020e6a41134c.jpg?v=1778859435","url":"https:\/\/klassik357.eu\/products\/vw-coolant-expansion-tank-cap-103643","provider":"Klassik357 - Classic and retro car parts","version":"1.0","type":"link"}