--- product_id: 110463112 title: "Class A Customs 40 Gallon RV Waste Black Water Holding Tank WT-4000" brand: "classacustoms" price: "$2080.47" currency: USD in_stock: true reviews_count: 8 category: "Class Acustoms" url: https://www.desertcart.us/products/110463112-class-a-customs-40-gallon-rv-waste-black-water-holding store_origin: US region: United States of America --- # 3” ABS Female Outlet 40 Gallon Capacity Made in USA MDPE Resin Class A Customs 40 Gallon RV Waste Black Water Holding Tank WT-4000 **Brand:** classacustoms **Price:** $2080.47 **Availability:** ✅ In Stock ## Summary > 🚐 Own the road with confidence—your ultimate RV waste solution awaits! ## Quick Answers - **What is this?** Class A Customs 40 Gallon RV Waste Black Water Holding Tank WT-4000 by classacustoms - **How much does it cost?** $2080.47 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/110463112-class-a-customs-40-gallon-rv-waste-black-water-holding) ## Best For - classacustoms enthusiasts ## Why This Product - Trusted classacustoms brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Lightweight Yet Rugged:** Easy to handle and install, but engineered to withstand the weight and rigors of full use—secure mounting recommended. - • **Integrated 3” ABS Outlet:** Factory-installed outlet streamlines your plumbing setup—just add your vent and dump valve for a custom fit. - • **Massive 40-Gallon Capacity:** Perfectly sized for extended RV trips or tiny house setups—never worry about frequent dumps again. - • **Premium USA-Made MDPE Resin:** Durable, seamless one-piece construction ensures no leaks or bursts—built tough for the road warriors. - • **Customizable Inlet & Vent Placement:** Design your system your way—tank comes ready for your personalized inlet and vent installation. ## Overview The Class A Customs 40 Gallon RV Waste Black Water Holding Tank WT-4000 is a robust, seamless, and lightweight tank made in the USA from high-quality Medium Density Polyethylene resin. Designed exclusively for waste and gray water, it features a fixed 3” ABS female outlet and customizable inlet and vent placements, making it ideal for RVs, campers, trailers, motorhomes, and tiny houses. Its durable construction ensures leak-free performance, while its large capacity supports extended travel or off-grid living. Note: fittings, valves, and mounting hardware are sold separately. ## Description RV Waste Water Holding Tank MADE IN THE USA by Class A Customs using Medium Density Polyethylene (MDPE) Resin TANK NOT FOR FRESH OR DRINKING WATER USE – WASTE/GRAY WATER USE ONLY -SEAMLESS One-piece construction, no seams to burst COLOR Black OEM PART No retail box - no install instructions Have a certified technician install all parts to prevent product damage and personal injury PREPARATION Tanks are made in a warehouse clean each tank prior to use to remove any debris, scuffs or marking from the manufacturing process INSTALLED OUTLET 3” ABS Female Pipe - outlet can not be moved DO NOT over-tighten fittings damage will occur Dump valves do not hook directly to the 3" ABS fitting, from the outlet run PVC or ABS piping, dump valve is added to the piping. INLET & VENT INSTALLATION Class A Customs Black Water Tanks only come with the outlet the end user will determine where the inlet and vent will need to be placed and install, hardware NOT included. TANK MUST BE VENTED allowing air in and out when in use. *DO NOT PRESSURIZE TANK* DO NOT over-tighten fittings damage will occur. MOUNTING & BRACING be sure to secure tank to prevent movement and be sure to secure due to weight when loaded DO NOT place weight on tank. ## Features - 40 Gallon RV Waste Water Holding Tank MADE IN THE USA by Class A Customs using Medium Density Polyethylene (MDPE) Resin TANK NOT FOR FRESH OR DRINKING WATER USE – WASTE/GRAY WATER USE ONLY – Used in RV’s Campers, Trailers, Motorhomes and Tiny Houses - INSTALLED OUTLET 3” ABS Female Pipe - outlet can not be moved DO NOT over-tighten fittings damage will occur Dump valves do not hook directly to the 3" ABS fitting, from the outlet run PVC or ABS piping (not included), dump valve (not included) is added to the piping. - INLET & VENT INSTALLATION Class A Customs Black Water Tanks only come with the outlet the end user will determine where the inlet and vent will need to be placed and install, hardware NOT included. TANK MUST BE VENTED allowing air in and out when in use. *DO NOT PRESSURIZE TANK* DO NOT over-tighten fittings damage will occur. - NOT INCLUDED Inlet and Vent Fittings / Additional Fittings / Hardware / Mounting Hardware / Dump Valve / Piping NOT INCLUDED ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B07NLLQDC1 | | Best Sellers Rank | #354,147 in Automotive ( See Top 100 in Automotive ) #34 in RV Black Water Tanks | | Brand | classAcustoms | | Brand Name | classAcustoms | | Capacity | 40 Gallons | | Color | Black | | Customer Reviews | 4.4 out of 5 stars 202 Reviews | | Item Dimensions L x W x H | 56.5"L x 24.5"W x 9"H | | Item Weight | 0.01 Ounces | | Manufacturer | Class A Customs | | Manufacturer Part Number | WT-4000 | | Material | Polyethylene (PE), Polyvinyl Chloride (PVC), Resin | | Material Type | Polyethylene (PE), Polyvinyl Chloride (PVC), Resin | | Product Dimensions | 56.5"L x 24.5"W x 9"H | | Shape | Rectangular | ## Product Details - **Brand:** classAcustoms - **Capacity:** 40 Gallons - **Color:** Black - **Material:** Polyethylene (PE), Polyvinyl Chloride (PVC), Resin - **Product Dimensions:** 56.5"L x 24.5"W x 9"H ## Images ![Class A Customs 40 Gallon RV Waste Black Water Holding Tank WT-4000 - Image 1](https://m.media-amazon.com/images/I/71NMcwKZRaL.jpg) ![Class A Customs 40 Gallon RV Waste Black Water Holding Tank WT-4000 - Image 2](https://m.media-amazon.com/images/I/71IdWHquJIS.jpg) ![Class A Customs 40 Gallon RV Waste Black Water Holding Tank WT-4000 - Image 3](https://m.media-amazon.com/images/I/512a8EyZKnS.jpg) ![Class A Customs 40 Gallon RV Waste Black Water Holding Tank WT-4000 - Image 4](https://m.media-amazon.com/images/I/71woS1w0UYL.jpg) ![Class A Customs 40 Gallon RV Waste Black Water Holding Tank WT-4000 - Image 5](https://m.media-amazon.com/images/I/711a3fh6A9L.jpg) ## Questions & Answers **Q: This tank showes an imput hole in the top. How big is it I couldn't find anything in the discription?** A: The top is a mold mark in the tank. In order to fill the tank you will need to use a hole saw bit and drill a hole into the tank where needed for your unit. Then place a plastic grommet to snug the pipe in, we also sell the grommets in 3" and 1 1/2". Thank you, Class A Customs Elkhart, Indiana **Q: What's the deal with the hose clamp on the outlet pipe** A: The hose clamp is used for holding the outlet pipe in place in addition to adhesive. **Q: Can this be used as an additional storing tank for waste? I still have the one on my camper but I want to add this one due to not having a septic yet.** A: I don't see why not..? It's up to you how you use it. But I replaced my tank and works great! **Q: what is the width of the bottom part of the tank? where can I find more details dimensions before ordering it?** A: Please be sure to view the CAD drawing on this tank, you will need to scroll through the photos to view it. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Review *by F***D on June 6, 2024* ### ⭐⭐⭐⭐⭐ Review *by T***T on December 19, 2025* ### ⭐⭐⭐⭐ Review *by A***R on September 15, 2020* ## Frequently Bought Together - Class A Customs 40 Gallon RV Waste Black Water Holding Tank WT-4000 - Valterra T50 3" Hub x 3" Bay with Cap Valve Assembly,Black - C.ROTO MOLDG Custom Roto-Molding 93 RV Tank Grommet --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.us/products/110463112-class-a-customs-40-gallon-rv-waste-black-water-holding](https://www.desertcart.us/products/110463112-class-a-customs-40-gallon-rv-waste-black-water-holding) --- *Product available on Desertcart United States of America* *Store origin: US* *Last updated: 2026-05-09*