{"product_id":"air-spring-bag-for-volvo-trucks-20505399-replacement-durable-fit","title":"Air Spring Bag for Volvo Trucks 20505399 Replacement - Durable Fit","description":"\u003cp\u003eIn this review of the Air Spring Bag that fits Volvo models including 20505399 and W01-358-8829, the bottom line is practical: this part is aimed at mechanics, fleet operators, and owner-operators who need a robust, direct replacement for air suspension systems. The reviewer found the product delivers durable construction and accurate fitment for specified Volvo part numbers, making it a sensible option where longevity and leak resistance matter. Verify Year\/Make\/Model before purchasing to ensure correct application.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Designed to fit multiple Volvo part numbers including 3934699, 8079902, 20733034, 20413888 and 20505399, which helps simplify parts sourcing for several truck models.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDimensions:\u003c\/strong\u003e The top plate width of 9in, piston width of 10in, extended height 20in and compressed height 6.1in give clear physical specs for installers to confirm fit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial Quality:\u003c\/strong\u003e Constructed from 4.5-5.00mm high density rubber, the bag aims to exceed OEM thickness and resist premature wear in heavy service.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReinforced Hardware:\u003c\/strong\u003e Uses 4140 grade steel studs claimed to be 25% stronger, which contributes to secure mounting and reduced risk of stud failure under load.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLeak Testing:\u003c\/strong\u003e Each spring bag is tested for maximum leakage, providing reassurance about air retention and real-world durability.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSupport:\u003c\/strong\u003e The seller offers after-sales service for questions, which helps with fitment or warranty concerns after purchase.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eWho It's For\u003c\/h2\u003e\u003cp\u003eThis air spring bag is best for professional installers, fleet maintenance teams and owner-operators who have Volvo trucks matching the listed part numbers and need a straightforward replacement part with robust construction. The explicit dimensions and reinforced studs make it suited for heavier duty use where longevity is a priority.\u003c\/p\u003e\u003cp\u003eThose who should look elsewhere include owners of trucks that do not match the listed part numbers or vehicles with altered suspension geometry; also buyers seeking a plug-and-play system with additional mounting accessories should confirm what hardware is included before purchasing.\u003c\/p\u003e\u003ch2\u003ePros \u0026amp; Cons\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003ePros\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eStands up to heavy use thanks to thick high density rubber that exceeds OEM requirements.\u003c\/li\u003e\n\u003cli\u003eClear dimensional specs and wide compatibility across several Volvo part numbers simplify selection and fit checks.\u003c\/li\u003e\n\u003cli\u003eReinforced 4140 steel studs and leak testing improve reliability and reduce downtime risk.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCons\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\u003cli\u003eLimited to the listed Volvo part numbers, so it is not universal and requires careful verification of Year\/Make\/Model before purchase.\u003c\/li\u003e\u003c\/ul\u003e\u003ch2\u003eSpecifications\u003c\/h2\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003eApplicable Models\u003c\/td\u003e\n\u003ctd\u003eVolvo 3934699, 8079902, 20733034, 20413888, 20505399\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAlternate Fit Numbers\u003c\/td\u003e\n\u003ctd\u003eW01-358-8829, SP558829-KP, AS8829\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTop Plate Width\u003c\/td\u003e\n\u003ctd\u003e9in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePiston Width\u003c\/td\u003e\n\u003ctd\u003e10in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eExtended Height\u003c\/td\u003e\n\u003ctd\u003e20in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompressed Height\u003c\/td\u003e\n\u003ctd\u003e6.1in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e14.2 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch2\u003eOur Verdict\u003c\/h2\u003e\u003cp\u003eFor operators who need a direct-replacement air spring for the specified Volvo part numbers, this bag represents solid value because of its thicker rubber construction, reinforced studs and leak-tested manufacturing. It is a practical, durable choice for routine suspension repairs when fitment is confirmed.\u003c\/p\u003e\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eWill this fit my Volvo truck?\u003c\/strong\u003e\u003cbr\u003eIt will fit if your truck uses one of the listed part numbers such as 20505399 or W01-358-8829; always verify Year\/Make\/Model before ordering.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs hardware included for installation?\u003c\/strong\u003e\u003cbr\u003eThe listing specifies reinforced studs but does not detail additional mounting hardware; check your kit contents or contact the seller for confirmation.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat indicates build quality?\u003c\/strong\u003e\u003cbr\u003eThe use of 4.5-5.00mm high density rubber, 4140 grade steel studs and leak testing are the key indicators of the stated durability and quality.\u003c\/p\u003e","brand":"STILEALUS","offers":[{"title":"Default Title","offer_id":48149475393755,"sku":"B0F384445M","price":75.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0724\/1043\/1707\/files\/61ucmCHIv1L._AC_SL1500.jpg?v=1768851084","url":"https:\/\/gearmusthave.com\/products\/air-spring-bag-for-volvo-trucks-20505399-replacement-durable-fit","provider":"GearMustHave","version":"1.0","type":"link"}