{"product_id":"acdelco-gm-original-equipment-rc85-15042975-15-p-s-i","title":"ACDelco GM Original Equipment RC85 (15042975) 15 P.S.I.","description":"\u003cp\u003e\u003cstrong\u003eACDelco RC85 (15042975) is a GM original equipment 15 PSI radiator cap engineered to seal the coolant system and maintain correct operating pressure for compatible GM vehicles.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWhen a cooling system doesn't hold pressure, engine temperatures and coolant boiling point can change, which may reduce system performance and increase risk of overheating. The ACDelco GM Original Equipment RC85 radiator cap is a direct-fit replacement designed to restore the original factory sealing, pressure relief and coolant recovery function found on many GM models. Built to OEM tolerances, this spring-loaded cap helps the cooling system operate as intended by controlling pressure and enabling coolant return from the expansion tank as the engine cools.\u003c\/p\u003e\n\n\u003ch3\u003eHow does this radiator cap maintain proper cooling system pressure?\u003c\/h3\u003e\n\u003cp\u003eThe RC85 uses a calibrated pressure spring and valve assembly to hold a 15 PSI threshold. While the engine warms, trapped air and expanding coolant increase pressure until the cap’s valve opens at the set rating, protecting hoses and radiator components from overpressure. As the engine cools, vacuum relief lets coolant return from the overflow reservoir to prevent air pockets.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e15 PSI spring-actuated pressure valve designed to match GM specifications\u003c\/li\u003e\n  \u003cli\u003eVacuum relief to allow coolant return and prevent tank collapse\u003c\/li\u003e\n  \u003cli\u003ePrecision sealing surface to minimize leaks and maintain system integrity\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWill the RC85 fit my GM vehicle and replace the original radiator cap?\u003c\/h3\u003e\n\u003cp\u003eThis ACDelco cap is an Original Equipment (OE) part manufactured to replace the factory component on compatible GM vehicles. It follows GM fitment guidelines and is intended as a direct replacement where RC85 or part number 15042975 is specified. Always confirm compatibility with your vehicle’s year, make and model before purchasing.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eOE part number 15042975 \/ RC85 for direct, vehicle-specific fit\u003c\/li\u003e\n  \u003cli\u003eDesigned to match factory sealing geometry and neck dimensions\u003c\/li\u003e\n  \u003cli\u003eRecommended by GM as a replacement for the original cap\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat are the practical benefits of using an OEM ACDelco radiator cap?\u003c\/h3\u003e\n\u003cp\u003eChoosing the ACDelco GM Original Equipment cap helps preserve the cooling system’s designed thermal performance by maintaining boiling point and minimizing air intrusion. Proper pressure control reduces strain on hoses, gaskets and the radiator, supporting longer component life and more consistent engine temperatures under everyday driving conditions.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eMaintains coolant boiling point for consistent thermal control\u003c\/li\u003e\n  \u003cli\u003ePrevents air pockets that can cause hot spots or reduced heater performance\u003c\/li\u003e\n  \u003cli\u003eHelps avoid premature wear on cooling system parts through correct pressure management\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow do I inspect and install the RC85 radiator cap safely?\u003c\/h3\u003e\n\u003cp\u003eAlways allow the engine to cool before removing the radiator cap. Inspect the cap’s seal, spring and valve for wear, corrosion or debris and replace if damaged. Installation requires a firm, even press and twist until the cap seats and locks, ensuring the pressure and vacuum functions operate correctly.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eOnly remove when the engine and coolant are cool to the touch\u003c\/li\u003e\n  \u003cli\u003eCheck the rubber seal and spring for cracks, rust or compression loss\u003c\/li\u003e\n  \u003cli\u003eSeat and twist firmly until the cap locks; verify no leaks at operating temperature\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: The ACDelco RC85 (15042975) 15 PSI radiator cap is aimed at owners and technicians maintaining GM cars, trucks and SUVs that require a factory-style replacement cap. It’s well suited for anyone restoring correct cooling system pressure and coolant recovery behavior on compatible GM models, and for service shops seeking an OE-grade component for reliable fit and performance.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Is this radiator cap compatible with my GM vehicle?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Check your vehicle’s OEM part number or compatibility list for RC85 \/ 15042975; it’s made to replace the factory cap on matching GM models.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can I remove the cap when the engine is hot?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: No — wait for the engine and coolant to cool to avoid scalding from pressurized hot coolant or steam.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"ACDelco","offers":[{"title":"Default Title","offer_id":48086846832798,"sku":"B000C9S78G","price":31.98,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/acdelco-rc85-front-view-cap.jpg?v=1785907735","url":"https:\/\/northtrailauto.ca\/products\/acdelco-gm-original-equipment-rc85-15042975-15-p-s-i","provider":"North Trail Auto","version":"1.0","type":"link"}