{"product_id":"arco-wp003-volvo-penta-indmar-ford-351-replacement-water-pump","title":"ARCO WP003 Volvo Penta \/ Indmar Ford 351 Replacement Water Pump | Replaces 3860703 \/ Sierra 18-3587-1","description":"\u003ch2\u003eARCO WP003 Volvo Penta \/ Indmar Ford 351 Replacement Water Pump\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003ePart Number:\u003c\/strong\u003e WP003 (ARCO)  |  \u003cstrong\u003eBrand:\u003c\/strong\u003e ARCO Marine  |  \u003cstrong\u003eUPC:\u003c\/strong\u003e 693006030111\u003c\/p\u003e\n\u003cp\u003eARCO \u003cstrong\u003eWP003\u003c\/strong\u003e is a complete premium replacement raw-water pump for compatible Volvo Penta, Indmar Ford 351, and most GM-based marine engine applications originally equipped with Volvo Penta pump \u003cstrong\u003e3860703\u003c\/strong\u003e. It restores the raw-water flow needed to keep the engine cooling system operating correctly when the original pump is leaking, worn, or no longer circulating water effectively. Every ARCO pump is factory-tested before packaging.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eImportant:\u003c\/strong\u003e WP003 is an ARCO aftermarket replacement pump — not a genuine Volvo Penta OEM assembly. Confirm fitment by the original pump number, not by engine displacement alone. Do not confuse WP003 with the \u003ca href=\"\/products\/11110180683812\"\u003eARCO WP002\u003c\/a\u003e, which replaces Volvo Penta pump references 841640 \/ 856952 \/ 857451 for the Indmar Ford 302 family.\u003c\/p\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e WP003\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e ARCO Marine\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Complete Raw-Water Pump Assembly\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSystem:\u003c\/strong\u003e Raw-water (seawater) engine cooling circuit\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 1,960 g \/ approx. 4.3 lb\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 693006030111\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eCompatible Applications\u003c\/h2\u003e\n\u003cp\u003eFitment is confirmed by the original pump number — not engine displacement or brand alone. Volvo Penta and marinized Ford \/ GM engines of the same family can use different pump configurations depending on year, serial range, and cooling-system arrangement.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eIndmar \u003cstrong\u003eFord 351\u003c\/strong\u003e marine engine applications\u003c\/li\u003e\n\u003cli\u003eMost GM-based marine engine applications using pump \u003cstrong\u003e3860703\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eVolvo Penta installations originally equipped with pump \u003cstrong\u003e3860703\u003c\/strong\u003e, including documented engine models:\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003e430 \/ 430A \/ 430B\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003e431A \/ 431B\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003e432A\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003e434A\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003e500B \/ 501B\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003e570 \/ 570A\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003e572A\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003e740A \/ 740B \/ BB740A\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eExact fitment should be verified by engine model, serial number, and existing pump reference number. Related Volvo Penta pump references \u003cstrong\u003e857451, 856952, and 856513\u003c\/strong\u003e are sometimes associated with the same crankshaft-driven pump family but are not confirmed as direct drop-in replacements for WP003 without verifying the pump number.\u003c\/p\u003e\n\n\u003ch2\u003eFitment Notice\u003c\/h2\u003e\n\u003cp\u003eBefore ordering, confirm the original pump or engine parts diagram references one of the following:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eARCO \u003cstrong\u003eWP003\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eVolvo Penta \u003cstrong\u003e3860703\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eSierra \u003cstrong\u003e18-3587-1\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eDo not confuse WP003 with the \u003ca href=\"\/products\/11110180683812\"\u003eARCO WP002\u003c\/a\u003e (Indmar Ford 302 \/ Volvo Penta 841640 \/ 856952 \/ 857451) — they are not interchangeable.\u003c\/p\u003e\n\n\u003ch2\u003eWhen to Replace the Pump\u003c\/h2\u003e\n\u003cp\u003eReplace the complete pump when any of the following are observed:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eCooling-water discharge is weak or absent at the exhaust\u003c\/li\u003e\n\u003cli\u003eEngine temperature rises despite correct coolant level\u003c\/li\u003e\n\u003cli\u003eWater leaks from the pump shaft seal or housing\u003c\/li\u003e\n\u003cli\u003eShaft or bearing play is present or the bearing is noisy\u003c\/li\u003e\n\u003cli\u003ePump housing is cracked or heavily corroded\u003c\/li\u003e\n\u003cli\u003ePump shaft binds or resists rotation\u003c\/li\u003e\n\u003cli\u003eRepeated impeller failures point to internal housing wear\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDisconnect the battery and allow the engine to cool completely before beginning service\u003c\/li\u003e\n\u003cli\u003eDrain the cooling system below the pump level\u003c\/li\u003e\n\u003cli\u003eRecord original belt routing and pulley position before removal\u003c\/li\u003e\n\u003cli\u003eInspect the drive belt, pulley, mounting hardware, and hose connections — replace worn items at the same service\u003c\/li\u003e\n\u003cli\u003eClean the mounting surface thoroughly before fitting the new pump\u003c\/li\u003e\n\u003cli\u003eInstall the correct gasket or sealing components per the engine service procedure\u003c\/li\u003e\n\u003cli\u003eTighten mounting bolts evenly to the specified torque\u003c\/li\u003e\n\u003cli\u003eConfirm pulley alignment with all belt-driven accessories before tensioning the belt\u003c\/li\u003e\n\u003cli\u003eIf the previous impeller lost blade material, inspect all downstream passages — hoses, oil cooler, heat exchanger — before starting the engine\u003c\/li\u003e\n\u003cli\u003eRefill the system with the specified coolant mixture; bleed trapped air per the engine manufacturer’s procedure\u003c\/li\u003e\n\u003cli\u003eRun the engine and verify strong raw-water discharge, no leaks, and stable operating temperature\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eCross-Reference Part Numbers\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eARCO:\u003c\/strong\u003e WP003\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVolvo Penta:\u003c\/strong\u003e 3860703\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSierra:\u003c\/strong\u003e 18-3587-1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 693006030111\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eRelated Products\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/8131492708388\"\u003eVolvo Penta Impeller Kit 3588475 — OEM Raw Water Pump Service Kit\u003c\/a\u003e — genuine OEM impeller service kit for related Volvo Penta raw-water pumps\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/8131485040676\"\u003eVolvo Penta D6 Raw Water Pump Impeller Kit 22994993\u003c\/a\u003e — related OEM impeller kit\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/8131496607780\"\u003eVolvo Penta Raw Water Pump Impeller Puller Screw 3843949\u003c\/a\u003e — impeller removal tool for Volvo Penta raw-water pumps\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/11110180683812\"\u003eARCO WP002 Volvo Penta \/ Indmar Ford 302 Replacement Water Pump\u003c\/a\u003e — WP003 sibling for Ford 302 \/ Volvo Penta 857451 applications\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eParts Desk Insights\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eBest use case:\u003c\/strong\u003e WP003 is the correct replacement when the raw-water pump on an Indmar Ford 351, a compatible GM-based marine engine, or a Volvo Penta 430–740-series installation is worn out and the original pump cross-references \u003cstrong\u003e3860703\u003c\/strong\u003e or Sierra \u003cstrong\u003e18-3587-1\u003c\/strong\u003e. It’s a complete factory-tested assembly — not a rebuilt unit — so you start fresh with no accumulated wear.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCommon issues:\u003c\/strong\u003e The most frequent ordering mistake is confusing WP003 with the \u003ca href=\"\/products\/11110180683812\"\u003eWP002\u003c\/a\u003e. Both are ARCO Volvo Penta \/ Indmar pumps and they look similar, but WP002 is the Ford 302 version and WP003 is the Ford 351 \/ GM version — they are not interchangeable. Always confirm against Volvo Penta \u003cstrong\u003e3860703\u003c\/strong\u003e before ordering. On repowered boats or engines that have had previous pump replacements, the installed pump may not match the original engine spec — check the pump tag or existing pump number directly rather than relying on the engine plate.\u003c\/p\u003e","brand":"LNS","offers":[{"title":"Default Title","offer_id":51156140589092,"sku":"57-WP003","price":727.19,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0743\/5799\/7604\/files\/47de1bfa-e8c5-4421-aea6-cbcf8ec79370.png?v=1785206451","url":"https:\/\/marisolmarine.com\/products\/arco-wp003-volvo-penta-indmar-ford-351-replacement-water-pump","provider":"Marisol Marine Company","version":"1.0","type":"link"}