{"product_id":"astamotor-front-engine-coolant-reservoir-for-kenworth-peterbilt-603-5403-durable-direct-fit","title":"ASTAMOTOR Front Engine Coolant Reservoir for Kenworth \u0026 Peterbilt — 603-5403, Durable Direct-Fit","description":"\u003cp\u003e\u003cstrong\u003eASTAMOTOR's 603-5403 front engine coolant reservoir is a direct-fit replacement expansion tank engineered to restore your Kenworth or Peterbilt cooling system reliability.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eIf the original coolant recovery tank on your heavy-duty truck has cracked, warped, or started leaking, replacing it with a quality, compatible unit prevents coolant loss and helps maintain proper cooling system pressure. This ASTAMOTOR reservoir corresponds to OE reference numbers 603-5403, 6035403, N5346001 and T1673008 and is molded from durable plastic designed to resist expansion and cracking under heavy thermal cycles typical of diesel rigs.\u003c\/p\u003e\n\n\u003ch3\u003eWill this reservoir fit my truck model?\u003c\/h3\u003e\n\u003cp\u003eYes — this ASTAMOTOR reservoir is made to match the original dimensions and mounting points of the listed Kenworth and Peterbilt models. Always verify the OE part numbers or compare the old tank to ensure identical inlet\/outlet locations and bracket positions before purchase.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eDirect replacement for OE 603-5403 \/ 6035403 \/ N5346001 \/ T1673008\u003c\/li\u003e\n  \u003cli\u003eCompatible Kenworth: T600 (2008–2015), T660 (2008–2017), T800 (2008–2017), W900 (2008–2017)\u003c\/li\u003e\n  \u003cli\u003eCompatible Peterbilt: 348, 365, 367, 377, 382, 384, 385, 386, 388, 389 (various 2008–2018 model years)\u003c\/li\u003e\n  \u003cli\u003eCheck hose fitting positions and mounting tabs to confirm fit\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow durable is the ASTAMOTOR coolant recovery tank?\u003c\/h3\u003e\n\u003cp\u003eThe tank is manufactured from high-quality plastic formulated to withstand repeated heating and cooling cycles without excessive deformation. That resilience reduces the chance of cracks or leaks over years of service, which is particularly important for long-haul and heavy-load operation.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003ePremium plastic resists thermal expansion and cracking\u003c\/li\u003e\n  \u003cli\u003ePrecision-molded inlet\/outlet and mounting points for a secure fit\u003c\/li\u003e\n  \u003cli\u003eMaterial selected for long-term exposure to coolant and heat\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow easy is installation and what should I expect?\u003c\/h3\u003e\n\u003cp\u003eInstallation is straightforward because this is a direct replacement designed to use the same mounting points and hose connections as the factory tank. Typical replacement requires basic hand tools and can often be completed in minutes once the old tank is removed and hoses disconnected.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eDirect bolt-in replacement — no modification required\u003c\/li\u003e\n  \u003cli\u003eSwap hoses and fasteners from the original tank to the new unit\u003c\/li\u003e\n  \u003cli\u003eBleed and top up coolant per manufacturer procedure after install\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat function does the coolant expansion tank perform?\u003c\/h3\u003e\n\u003cp\u003eThe recovery tank captures expanding coolant when the engine warms and returns it to the system as the engine cools, helping maintain proper coolant level and pressure balance. A reliable reservoir prevents air pockets and reduces the risk of overheating due to coolant loss.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eBalances cooling system pressure during thermal cycles\u003c\/li\u003e\n  \u003cli\u003eStores and returns coolant to prevent air entry into the system\u003c\/li\u003e\n  \u003cli\u003eHelps maintain correct coolant level to support engine temperature control\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: Truck owners, fleet managers, and professional technicians who operate or maintain Kenworth T600\/T660\/T800\/W900 and multiple Peterbilt models (listed above) and need a dependable, OEM-matching coolant recovery tank. Choose this ASTAMOTOR unit when you want a durable, direct-fit replacement that restores system integrity and reduces the chance of leaks or overheating due to a compromised reservoir.\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: Does this replace OE part 603-5403?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes — it directly replaces OE 603-5403, 6035403, N5346001 and T1673008.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can I install this myself?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes — it’s a bolt-in replacement using original hose and fasteners; basic tools are required.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"ASTAMOTOR","offers":[{"title":"Default Title","offer_id":67584902856889,"sku":"B0CRB59XB6","price":292.46,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0822\/3765\/3177\/files\/astamotor-front-view-coolant-reservoir.jpg?v=1790458393","url":"https:\/\/redleafauto.ca\/products\/astamotor-front-engine-coolant-reservoir-for-kenworth-peterbilt-603-5403-durable-direct-fit","provider":"Redleaf Auto","version":"1.0","type":"link"}