{"product_id":"yanmar-cooler-gasket-129693-44420-4jh-series","title":"Yanmar Cooler Gasket 129693-44420 — 4JH Series Marine Diesel Engine","description":"\u003ch2\u003eYanmar Cooler Gasket 129693-44420\u003c\/h2\u003e\u003cp\u003eThis genuine Yanmar OEM cooler gasket seals the heat exchanger or oil cooler assembly on 4JH series marine diesel engines. The cooler circuit operates under sustained heat and pressure cycling — conditions that quickly expose any compromise in gasket integrity. Using the correct OEM gasket ensures the right material composition, thickness, and cut profile to maintain a leak-free seal at the cooler mating surfaces.\u003c\/p\u003e\u003cp\u003eThis gasket is a standard replacement item during heat exchanger cleaning, raw water circuit service, or any time the cooler assembly is opened. Never reuse a previously compressed gasket — it will not re-seal reliably.\u003c\/p\u003e\u003ch3\u003ePart Details\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e 129693-44420\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Yanmar\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eType:\u003c\/strong\u003e Cooler \/ Heat Exchanger Gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSystem:\u003c\/strong\u003e Cooling System — Heat Exchanger \/ Oil Cooler\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM \/ Aftermarket:\u003c\/strong\u003e Genuine OEM\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine Family:\u003c\/strong\u003e Yanmar 4JH Series Marine Diesel\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eCompatible Applications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eYanmar 4JH series marine diesel engines\u003c\/li\u003e\n\u003cli\u003eVerify fitment using your engine model and serial number against the Yanmar parts diagram for your specific 4JH variant (4JH2, 4JH3, 4JH4, 4JHE, 4JH-TE, 4JH-HTE, 4JH-DTE)\u003c\/li\u003e\n\u003cli\u003eConsult your Yanmar service manual to confirm cooler position and gasket part number before ordering\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eService Interval\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eReplace any time the heat exchanger or cooler is disassembled — never reuse a previously installed gasket\u003c\/li\u003e\n\u003cli\u003eInspect for coolant or oil seepage at every scheduled service (250 hours or annually)\u003c\/li\u003e\n\u003cli\u003eReplace immediately if weeping or staining is observed at the cooler joint\u003c\/li\u003e\n\u003cli\u003eRecommended replacement during annual winterization or spring commissioning if the cooler has been opened\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eRelated Parts\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/yanmar-marine-engine-water-pump-gasket-129486-42050\"\u003eYanmar Water Pump Gasket 129486-42050\u003c\/a\u003e — OEM cooling system seal for 4JH series\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/yanmar-53\"\u003eYanmar Thermostat Gasket 129150-49811\u003c\/a\u003e — thermostat gasket for 4JH series engines\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/yanmar-oem-coolant-filler-cap-2ym-3ym-3jh-4jh-series-129673-44131\"\u003eYanmar OEM Coolant Filler Cap — 4JH Series 129673-44131\u003c\/a\u003e — cooling system service item\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/yan-121\"\u003eYanmar Genuine Coolant YG30R\u003c\/a\u003e — OEM antifreeze\/coolant for Yanmar marine diesels\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/yanmar-cooler-gasket-127881-18180\"\u003eYanmar Cooler Gasket 127881-18180\u003c\/a\u003e — cooler gasket for other Yanmar engine families\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eTechnical FAQ\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eQ: Can I reuse this gasket if the cooler was only briefly opened?\u003c\/strong\u003e\u003cbr\u003eA: No. Cooler gaskets compress and conform on first installation. Even brief disassembly breaks the seal. Always fit a new gasket on reassembly.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eQ: Should I use sealant with this gasket?\u003c\/strong\u003e\u003cbr\u003eA: Yanmar OEM gaskets are generally installed dry. Do not add RTV or thread sealant unless your Yanmar service manual specifically calls for it at this joint.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eQ: What causes cooler gaskets to fail prematurely?\u003c\/strong\u003e\u003cbr\u003eA: The most common causes are improper torque sequence, reuse of old gaskets, contaminated or corroded mating surfaces, and coolant system overpressure from a failing pressure cap.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eQ: How do I confirm this is the correct gasket for my engine?\u003c\/strong\u003e\u003cbr\u003eA: Cross-reference your engine model and serial number with the Yanmar parts diagram for your specific 4JH variant. Serial number determines which sub-variant and parts revision applies.\u003c\/p\u003e\u003ch3\u003eParts Desk Insights\u003c\/h3\u003e\u003cp\u003eThis gasket is most commonly needed during heat exchanger cleaning — a service that should happen every 1–2 years on a saltwater-cooled engine to clear scale and debris from the raw water side. When you pull the heat exchanger end caps or disassemble the cooler stack, this gasket needs to come out with it. The most common mistake is trying to reuse the old gasket or skipping the gasket entirely and using RTV — neither holds up under the pressure and temperature cycling of a marine diesel cooling circuit. If you're doing a full cooling system service, order the thermostat gasket and water pump gasket at the same time so you're not making a second trip for parts mid-job.\u003c\/p\u003e","brand":"YAN","offers":[{"title":"Default Title","offer_id":43564307841060,"sku":"129693-44420","price":18.26,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0743\/5799\/7604\/files\/129693-44420.png?v=1771182690","url":"https:\/\/marisolmarine.com\/products\/yanmar-cooler-gasket-129693-44420-4jh-series","provider":"Marisol Marine Company","version":"1.0","type":"link"}