{"product_id":"arco-wp004-mercruiser-v8-raw-water-pump-46-72774a32","title":"ARCO WP004 MerCruiser V8 Raw-Water Pump | V-Belt Two-Piece | Replaces 46-72774A32 \/ Sierra 18-3600","description":"\u003ch2\u003eARCO WP004 MerCruiser V8 Replacement Raw-Water Pump\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003ePart Number:\u003c\/strong\u003e WP004 (ARCO)  |  \u003cstrong\u003eBrand:\u003c\/strong\u003e ARCO Marine  |  \u003cstrong\u003eUPC:\u003c\/strong\u003e 693006030173\u003c\/p\u003e\n\u003cp\u003eARCO \u003cstrong\u003eWP004\u003c\/strong\u003e is a complete premium replacement raw-water pump for selected MerCruiser V8 marine engines equipped with a \u003cstrong\u003eV-belt drive and two-piece seawater pump configuration\u003c\/strong\u003e. It restores raw-water circulation through the engine cooling system when the original pump assembly is worn, leaking, or no longer moving water effectively. Every ARCO pump is factory-tested before packaging.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eImportant:\u003c\/strong\u003e WP004 is an ARCO aftermarket replacement pump — not a genuine Mercury \/ Quicksilver OEM assembly. Fitment is specific to the \u003cstrong\u003eV-belt, two-piece pump configuration\u003c\/strong\u003e. MerCruiser V8 engines with serpentine-belt drives or one-piece pump assemblies use a different pump. Confirm by the original pump number and accessory-drive layout before ordering.\u003c\/p\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e WP004\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\u003eDrive Type:\u003c\/strong\u003e V-belt\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePump Configuration:\u003c\/strong\u003e Two-piece seawater pump\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 3,370 g \/ approx. 7.4 lb\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 693006030173\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eCompatible Applications\u003c\/h2\u003e\n\u003cp\u003eFitment is confirmed by the existing pump number and accessory-drive configuration — not by engine displacement or model year alone. Confirmed for:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eMerCruiser V8 marine engines with \u003cstrong\u003eV-belt accessory drive\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eEngines equipped with the \u003cstrong\u003etwo-piece raw-water pump assembly\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eInstallations where the existing pump cross-references one of the following original part numbers:\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e46-72774A32\u003c\/strong\u003e \/ \u003cstrong\u003e72774A32\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e72774A11\u003c\/strong\u003e \/ \u003cstrong\u003e46-72774A11\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e73823A7\u003c\/strong\u003e \/ \u003cstrong\u003e46-73823A7\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e59112A2\u003c\/strong\u003e \/ \u003cstrong\u003e46-59112A2\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e46-63450A2\u003c\/strong\u003e (additional catalog reference)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eDo not order by engine displacement alone. Later MerCruiser V8 engines with serpentine-belt drives and one-piece pump assemblies require a different pump. Confirm the belt arrangement and pump configuration from the engine serial number parts diagram before ordering.\u003c\/p\u003e\n\n\u003ch2\u003eFitment Notice\u003c\/h2\u003e\n\u003cp\u003eBefore ordering, verify all of the following for your installation:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eApplication is a \u003cstrong\u003eMerCruiser V8\u003c\/strong\u003e engine\u003c\/li\u003e\n\u003cli\u003eAccessory drive uses a \u003cstrong\u003eV-belt\u003c\/strong\u003e (not serpentine)\u003c\/li\u003e\n\u003cli\u003ePump is the \u003cstrong\u003etwo-piece seawater pump configuration\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eExisting pump number matches one of the cross-references above\u003c\/li\u003e\n\u003cli\u003eHose sizes, port arrangement, and mounting hardware are compatible\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhen to Replace the Pump\u003c\/h2\u003e\n\u003cp\u003eReplace the complete pump assembly when any of the following are observed:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eRaw-water flow remains weak after installing a new impeller\u003c\/li\u003e\n\u003cli\u003ePump housing is internally scored, corroded, or worn\u003c\/li\u003e\n\u003cli\u003ePump shaft develops play or the bearing becomes noisy\u003c\/li\u003e\n\u003cli\u003eWater leaks from the shaft seal or pump body\u003c\/li\u003e\n\u003cli\u003eBelt pulley is damaged, loose, or misaligned\u003c\/li\u003e\n\u003cli\u003eEngine temperature rises despite a clear raw-water intake and serviceable impeller\u003c\/li\u003e\n\u003cli\u003ePump assembly is physically damaged or seized\u003c\/li\u003e\n\u003cli\u003eRepeated impeller failures point to wear inside the pump housing\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eConfirm the engine serial number and original pump reference before beginning removal\u003c\/li\u003e\n\u003cli\u003eClose the raw-water intake seacock and disconnect the battery before working near the belt drive\u003c\/li\u003e\n\u003cli\u003eRecord original V-belt routing and pulley alignment before removal\u003c\/li\u003e\n\u003cli\u003eInspect the V-belt, cooling hoses, and clamps — replace worn items at the same service\u003c\/li\u003e\n\u003cli\u003eAlign the pump pulley carefully with the remaining engine accessories before tensioning the belt\u003c\/li\u003e\n\u003cli\u003eSet belt tension per the MerCruiser service procedure\u003c\/li\u003e\n\u003cli\u003ePrime the pump and restore the raw-water supply before starting the engine\u003c\/li\u003e\n\u003cli\u003eIf the previous impeller lost blade material, inspect downstream passages — hoses, coolers, thermostat housings — before startup\u003c\/li\u003e\n\u003cli\u003eRun the engine and verify strong raw-water discharge at the exhaust, correct temperature, and no leaks at the pump, hoses, or connections\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 WP004\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMerCruiser \/ Quicksilver:\u003c\/strong\u003e 46-72774A32, 72774A11 (46-72774A11), 73823A7 (46-73823A7), 59112A2 (46-59112A2), 46-63450A2\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSierra:\u003c\/strong\u003e 18-3600\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGLM:\u003c\/strong\u003e 12093\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 693006030173\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\/8131436019748\"\u003eMercury MerCruiser Water Pump Repair Kit 89984T5\u003c\/a\u003e — impeller and seal service kit for MerCruiser raw-water pumps\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/11110180651044\"\u003eARCO WP001 MerCruiser Brass Seawater Pump | Replaces 8M0139984 \/ 862914A13\u003c\/a\u003e — ARCO replacement for current-style MerCruiser seawater pump\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/11110180782116\"\u003eARCO IP001 Mercury \/ MerCruiser Seawater Pump Impeller | Replaces 47-8M0104229\u003c\/a\u003e — MerCruiser impeller replacement\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/11110178226212\"\u003eSierra 3160-1 MerCruiser Sea Water Pump — Brass\u003c\/a\u003e — alternative brass seawater pump for MerCruiser applications\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/8131443851300\"\u003eQuicksilver Water Pump Drive Pulley 8M0153706\u003c\/a\u003e — OEM MerCruiser seawater pump drive pulley\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/8131443621924\"\u003eMercury MerCruiser Seawater Pump Pulley — 8M0150724\u003c\/a\u003e — MerCruiser seawater pump pulley\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 WP004 is the correct choice when a MerCruiser V8 with the older V-belt, two-piece pump layout has a failed or leaking seawater pump and the original number cross-references the 72774A-series. It’s a complete factory-tested assembly, so you’re replacing everything — housing, shaft, seal, and impeller — rather than trying to salvage a worn housing with a new impeller. That matters on high-hour engines where the pump bore is often the real reason cooling performance has dropped despite repeated impeller replacements.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCommon issues:\u003c\/strong\u003e The most frequent ordering mistake is not confirming the belt arrangement first. MerCruiser V8 engines were produced with both V-belt and serpentine-belt accessory drives, and the two pump types are not interchangeable. Check the existing pump and belt before ordering. The second issue is selection by engine displacement alone — multiple pump assemblies were used across MerCruiser V8 production runs, so matching the original \u003cstrong\u003e72774A32 \/ 72774A11 \/ 73823A7 \/ 59112A2\u003c\/strong\u003e number from the pump casting or engine parts diagram is the only reliable fitment check.\u003c\/p\u003e","brand":"LNS","offers":[{"title":"Default Title","offer_id":51156140621860,"sku":"57-WP004","price":854.99,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0743\/5799\/7604\/files\/e8540d2f-6725-4f0b-9729-d74491678f85.png?v=1785206117","url":"https:\/\/marisolmarine.com\/products\/arco-wp004-mercruiser-v8-raw-water-pump-46-72774a32","provider":"Marisol Marine Company","version":"1.0","type":"link"}