{"product_id":"harley-x440-rear-brake-fluid-reservoir-hdh43550-aaz-310","title":"Harley-Davidson X440 \/ X440 OBDII Rear Brake Fluid Reservoir OEM | HDH43550AAZ310","description":"\u003cp\u003e\u003cstrong\u003eReplace a cracked, leaking, faded, or damaged rear brake fluid reservoir with this genuine OEM reservoir assembly for Harley-Davidson X440 series motorcycles.\u003c\/strong\u003e Part number \u003cstrong\u003eHDH43550-AAZ-310\u003c\/strong\u003e is listed in the genuine parts record as \u003cstrong\u003eRESERVOIR COMP RR\u003c\/strong\u003e. In buyer language, this is best understood as the \u003cstrong\u003erear brake fluid reservoir\u003c\/strong\u003e, \u003cstrong\u003erear brake oil bottle\u003c\/strong\u003e, or \u003cstrong\u003erear master cylinder reservoir\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003eThis is the small fluid reservoir used with the \u003cstrong\u003erear brake hydraulic system\u003c\/strong\u003e. If the original reservoir body is cracked, the plastic is damaged or discolored, fluid is leaking, or the reservoir is being replaced during brake system repair, this OEM part helps restore proper fit and fluid storage for the listed applications.\u003c\/p\u003e\n\n\u003cp\u003eThis listing is written to be easier for customers to understand. Instead of only using the factory term \u003cstrong\u003eRESERVOIR COMP RR\u003c\/strong\u003e, it also uses the common buyer names:\n\u003cstrong\u003erear brake fluid reservoir\u003c\/strong\u003e, \u003cstrong\u003erear brake oil bottle\u003c\/strong\u003e, and \u003cstrong\u003erear master cylinder reservoir\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003eThis part is confirmed for the following applications based on your genuine parts applicability screenshot:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\u003cstrong\u003eHarley-Davidson X440 (Sept 2023)\u003c\/strong\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003cstrong\u003eHarley-Davidson X440 OBDII (May 2025)\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eNot confirmed in the provided evidence:\u003c\/strong\u003e X440T, X440X, and Hero Mavrick 440. Please do not assume wider fitment unless your old part, VIN, or EPC reference confirms the same part number.\u003c\/p\u003e\n\n\u003cp\u003eThis listing is for \u003cstrong\u003eone rear brake fluid reservoir only\u003c\/strong\u003e. Do not assume it includes the master cylinder, hose, cap, bracket, rear caliper, or a complete rear brake assembly unless separately stated.\u003c\/p\u003e\n\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eGenuine OEM rear brake fluid reservoir\u003c\/li\u003e\n  \u003cli\u003ePart number: HDH43550-AAZ-310\u003c\/li\u003e\n  \u003cli\u003eFactory description: RESERVOIR COMP RR\u003c\/li\u003e\n  \u003cli\u003eBuyer language: rear brake fluid reservoir, rear brake oil bottle, rear master cylinder reservoir\u003c\/li\u003e\n  \u003cli\u003eConfirmed for X440 and X440 OBDII\u003c\/li\u003e\n  \u003cli\u003eUsed in the rear brake hydraulic system\u003c\/li\u003e\n  \u003cli\u003eUseful for replacing cracked, leaking, or damaged reservoir units\u003c\/li\u003e\n  \u003cli\u003eHelps maintain correct brake fluid storage and OEM-style fit\u003c\/li\u003e\n  \u003cli\u003eImportant distinction from master cylinder and full rear brake assembly\u003c\/li\u003e\n  \u003cli\u003eOEM-style fit for the listed applications\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\n    \u003ctr\u003e\n      \u003cth\u003eMake\u003c\/th\u003e\n      \u003cth\u003eModel \/ Variant\u003c\/th\u003e\n      \u003cth\u003ePlatform\u003c\/th\u003e\n      \u003cth\u003eYears (Approx.)\u003c\/th\u003e\n      \u003cth\u003eFitment Status\u003c\/th\u003e\n      \u003cth\u003eNotes\u003c\/th\u003e\n    \u003c\/tr\u003e\n  \u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eHarley-Davidson\u003c\/td\u003e\n      \u003ctd\u003eX440\u003c\/td\u003e\n      \u003ctd\u003eHarley X440\u003c\/td\u003e\n      \u003ctd\u003eSept 2023\u003c\/td\u003e\n      \u003ctd\u003eConfirmed\u003c\/td\u003e\n      \u003ctd\u003eShown in applicable models list for HDH43550-AAZ-310.\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eHarley-Davidson\u003c\/td\u003e\n      \u003ctd\u003eX440 OBDII\u003c\/td\u003e\n      \u003ctd\u003eHarley X440\u003c\/td\u003e\n      \u003ctd\u003eMay 2025\u003c\/td\u003e\n      \u003ctd\u003eConfirmed\u003c\/td\u003e\n      \u003ctd\u003eShown in applicable models list for HDH43550-AAZ-310.\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eHarley-Davidson\u003c\/td\u003e\n      \u003ctd\u003eX440T\u003c\/td\u003e\n      \u003ctd\u003eHarley X440 T\u003c\/td\u003e\n      \u003ctd\u003e\u003c\/td\u003e\n      \u003ctd\u003eVerify by VIN \/ EPC \/ old part match\u003c\/td\u003e\n      \u003ctd\u003eNot confirmed in the provided applicability list.\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eHarley-Davidson\u003c\/td\u003e\n      \u003ctd\u003eX440X\u003c\/td\u003e\n      \u003ctd\u003eHarley X440 family\u003c\/td\u003e\n      \u003ctd\u003e\u003c\/td\u003e\n      \u003ctd\u003eVerify by VIN \/ EPC \/ old part match\u003c\/td\u003e\n      \u003ctd\u003eNot confirmed in the provided applicability list.\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eHero\u003c\/td\u003e\n      \u003ctd\u003eMavrick 440\u003c\/td\u003e\n      \u003ctd\u003eHero 440 platform\u003c\/td\u003e\n      \u003ctd\u003e\u003c\/td\u003e\n      \u003ctd\u003eVerify by VIN \/ EPC \/ old part match\u003c\/td\u003e\n      \u003ctd\u003eNot confirmed in the provided applicability list.\u003c\/td\u003e\n    \u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eWhat's in the Box\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e1 x HDH43550-AAZ-310 – Rear Brake Fluid Reservoir (RESERVOIR COMP RR)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eInstallation \u0026amp; Maintenance Notes\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eThis listing is for \u003cstrong\u003eone rear brake fluid reservoir only\u003c\/strong\u003e.\u003c\/li\u003e\n  \u003cli\u003ePlease match your old part number, shape, and hose connection before ordering.\u003c\/li\u003e\n  \u003cli\u003eDo not assume this includes the rear master cylinder or cap unless separately stated.\u003c\/li\u003e\n  \u003cli\u003eInspect hose condition, mounting area, and brake fluid level\/system condition during replacement.\u003c\/li\u003e\n  \u003cli\u003eBrake work should be done carefully and correctly. If unsure, use a qualified mechanic.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eBefore You Order\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eImportant:\u003c\/strong\u003e This is the OEM part identified as \u003cstrong\u003eRESERVOIR COMP RR\u003c\/strong\u003e, presented in buyer language as the \u003cstrong\u003erear brake fluid reservoir\u003c\/strong\u003e. It is not the complete rear master cylinder and not the rear caliper.\u003c\/p\u003e\n\n\u003cp\u003eFor \u003cstrong\u003eX440T\u003c\/strong\u003e, \u003cstrong\u003eX440X\u003c\/strong\u003e, or \u003cstrong\u003eHero Mavrick 440\u003c\/strong\u003e, fitment is not confirmed in the provided applicability record. Please verify by \u003cstrong\u003eVIN \/ EPC \/ old part match\u003c\/strong\u003e before ordering.\u003c\/p\u003e\n\n\u003ch3\u003eWhy Buy From Under The Hood\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eBuyer-friendly naming for technical OEM brake parts\u003c\/li\u003e\n  \u003cli\u003eClear explanation of what the reservoir actually is\u003c\/li\u003e\n  \u003cli\u003eHelpful distinction between reservoir, master cylinder, and full brake assembly\u003c\/li\u003e\n  \u003cli\u003eUseful for owners and workshops ordering exact brake hydraulic parts\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFAQs\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003e1. What is HDH43550-AAZ-310?\u003c\/strong\u003e\u003cbr\u003e\nIt is the OEM part listed as \u003cstrong\u003eRESERVOIR COMP RR\u003c\/strong\u003e, best understood in buyer language as the \u003cstrong\u003erear brake fluid reservoir\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003e2. Which bikes is this confirmed for?\u003c\/strong\u003e\u003cbr\u003e\nThis part is confirmed for \u003cstrong\u003eHarley-Davidson X440\u003c\/strong\u003e and \u003cstrong\u003eHarley-Davidson X440 OBDII\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003e3. Is this the complete rear master cylinder?\u003c\/strong\u003e\u003cbr\u003e\nNo. This listing is for the \u003cstrong\u003erear brake fluid reservoir\u003c\/strong\u003e only, not automatically the full rear master cylinder assembly.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003e4. Will it fit X440T?\u003c\/strong\u003e\u003cbr\u003e\nPlease verify by \u003cstrong\u003eVIN \/ EPC \/ old part match\u003c\/strong\u003e before ordering. X440T is not confirmed in the provided applicability list.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003e5. Will it fit Hero Mavrick 440?\u003c\/strong\u003e\u003cbr\u003e\nPlease verify before ordering. Mavrick 440 is not confirmed in the provided applicability list.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003e6. When should this part be replaced?\u003c\/strong\u003e\u003cbr\u003e\nReplace it when the reservoir is cracked, leaking, damaged, discolored, or no longer serviceable during brake repair.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003e7. What should be checked before ordering?\u003c\/strong\u003e\u003cbr\u003e\nPlease confirm the exact bike variant, old part match, and whether you need only the reservoir or a larger rear brake repair assembly.\u003c\/p\u003e","brand":"Harley-Davidson","offers":[{"title":"Default Title","offer_id":51201378451751,"sku":"HDH43550-AAZ-310","price":61.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0878\/7447\/0183\/files\/967201DE-D12F-47B4-B85E-CFE460BE774F.jpg?v=1774517641","url":"https:\/\/underthehood.co.in\/products\/harley-x440-rear-brake-fluid-reservoir-hdh43550-aaz-310","provider":"UNDER THE HOOD","version":"1.0","type":"link"}