Fuel Injector Line Passthrough Seals for Detroit Diesel DD15 – Replace A4720780180 A4720780480 – Cup Seals for Freightliner Cascadia, Western Star, Mack & Volvo Heavy Duty Trucks

High-Performance Fuel Injector Line Passthrough Seals for Detroit Diesel DD15 EnginesMaintain the integrity of your heavy-duty engine's fuel system with these precision-engineered Injector Line Passthrough Seals (Cup Seals). Designed specifically for the demanding environment of the Detroit Diesel DD15 platform, these seals prevent costly fuel leaks that can lead to severe engine damage.⚠️ CRITICAL APPLICATION INFORMATIONThis seal kit is engineered ONLY for Detroit Diesel DD15 engines. It replaces factory parts showing signs of wear, hardening, or leakage around the injector line entry points.✅ COMPATIBLE PART NUMBERS:A4720780180A4720780480(Supersedes older variations; verify with VIN if unsure)✅ COMPATIBLE ENGINES:Detroit Diesel DD15 (All Model Years)✅ COMPATIBLE TRUCK MODELS:Freightliner: Cascadia, Coronado, Business Class M2Western Star: 4700, 4900, 5700, 6900Mack Trucks: Granite, Pinnacle, TerraPro (Equipped with DD15)Volvo Trucks: VNL, VNX, VHD (Equipped with DD15)Common Symptoms of Failed SealsFuel dilution in engine oil (oil level rises, smells like diesel)Hard starting or rough idle due to pressure lossExcessive black or white smoke from exhaustVisible fuel weeping around injector lines at the cylinder headDiagnostic codes related to fuel rail pressure or injector circuit leaksProduct SpecificationsMaterial: High-Density Fluoroelastomer (FKM/Viton-style)Temperature Range: Rated for extreme under-hood diesel engine temperaturesChemical Resistance: Superior resistance to Ultra-Low Sulfur Diesel (ULSD) and biodiesel blendsDesign: Precision-molded cup shape for perfect line seatingFitment: Direct OEM replacement (No modifications required)Key FeaturesPrevent Engine Damage: Stops fuel from washing down cylinder walls or contaminating the oil pan, protecting bearings and extending oil change intervals.Superior Material Science: Unlike standard nitrile rubber, our FKM compound resists hardening and cracking caused by heat cycles and modern diesel fuels.Perfect Seal: Engineered to exact OEM tolerances to ensure a leak-free connection between the fuel line and the cylinder head passthrough.Fleet Reliable: Trusted quality for owner-operators and large fleets requiring minimal downtime and maximum reliability.Installation RecommendationsSafety: Depressurize the fuel system completely before removing lines. Work in a well-ventilated area.Cleanliness: Thoroughly clean the passthrough bore and fuel line ends. Any debris will compromise the new seal.Replacement: Remove old cups carefully without scratching the metal seating surface. Lubricate new seals lightly with clean diesel or assembly lube before installation.Torque: Reinstall fuel lines and torque to manufacturer specifications. Do not overtighten.Leak Check: Prime the system and check for leaks before returning the truck to service.Package Contents1 x Set of Fuel Injector Line Passthrough Seals (Quantity per pack as specified: typically 1 set per injector line repair)Note: For a full engine service, multiple packs may be required (one per injector line).Quality AssuranceManufactured to meet or exceed OEM specifications for the Detroit Diesel DD15 platform. Proper installation of these seals is critical for engine longevity and emissions compliance.

• 【🔧 REPLACES OEM NUMBERS】 Direct replacement for A4720780180 and A4720780480. Fits Detroit Diesel DD15 injector line passthrough ports. Solves leaks causing fuel dilution in engine oil. Verify part number before ordering.
• 【🚛 BROAD COMPATIBILITY】 Designed for Detroit DD15 engines found in Freightliner Cascadia, Western Star (4700/4900/5700), Mack (Granite/Pinnacle), and Volvo (VNL/VNX) heavy-duty trucks. Essential for fleet maintenance.
• 【🛑 STOP FUEL LEAKS】 Critical seal prevents high-pressure fuel from leaking into the cylinder head or oil pan. Fixes symptoms like hard starting, excessive smoke, rising oil level, and fuel smell in crankcase.
• 【🌡️ HIGH-TEMP DURABILITY】 Made from advanced fluoroelastomer (FKM) material. Resists extreme heat, diesel fuel corrosion, and pressure spikes better than standard rubber, ensuring long-term sealing integrity.
• 【📦 INSTALLATION READY】 Package includes 1 Set of Passthrough Seals (Cups). Direct fit requires no modification. Recommended to replace during injector service or when leak codes appear. Professional install advised.