40 Gallon Waste Water Tank

WT-4000 | WASTE TANK 40 Gallon Water Holding Tank | WT-4000

Your Price: $159.95

Questions about this item? Ask here.

Part Number: WT-4000

Availability: In Stock. 166

Free Shipping - View Shipping Method Tab Below

Quantity	Price
5 - 9	$157.50
10 - 24	$154.95
25+	$150.95

Quantity

Description
Questions & Answers
Preparation & Installation
Warranty
Shipping Method

Waste Water Tank Used for Human Waste or Gray Water - DO NOT use for fresh or drinking water

Non-pressurized Tank all tanks we carry must be vented (allow air in/out during use), Plumbing Example

Waste Or Gray Water Use great for rvs, food vendors, tiny houses, overlanding and extra waste water storage

Seamless One-piece seamless construction, no seams to burst Average tank thickness: .219 or 7/32" thick (just under 1/4")

Resistant Stain, Corrosion and Rust Resistant

Color Black in color so tank is easily identified as a waste tank

Made With Recycled Medium Density Polyethylene (MDPE) Resin - glues do not stick to this material and easily cleaned. - Because product is recycled and intended for waste use it is not tested for safety of drinking or gardening water supply.

Installed Outlet Options

3” ABS Female Pipe - outlet can not be moved

Inlet & Vent
Class A Customs Waste Water Tanks only come with the outlet the end user will determine where the inlet and vent will need to be placed and install.

Overall Measurements - See Photos

56.5” x 24.5” x 9”

Q: How is the tank generally secured to the bottom of the trailer?

Asked by: Richard - 3/16/2023

A: Some of the Class A Customs Waste Water Tanks are built with a "lip" on the tank. Tanks can be hung by this lip, it is recommended to make a shelf to slide the tank lip into. You will need to brace the tank on all sides to prevent movement of the tank.

Brackets or Strap Systems
Due to the variety of installations we do not carry brackets or bracing systems. Do Not hang by ratchet strap, this is too thin and will not adequately support tank.

https://www.classacustoms.com/Bracing-and-Supporting-Water-Tanks_b_50.html

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Answer provided by: Administrator (5/31/2023)

Q: Do you ship to Australia

Asked by: Will - 8/2/2023

A: Shipping Methods
Class A Customs currently ships FedEx and USPS mail.
Our only shipping location is in Elkhart, Indiana.
Free Shipping ships to the 48 Contiguous U.S. only.
Calculated Shipping ships anywhere within the U.S.
Water Tanks Free Shipping tanks ship FedEx Ground or Home Delivery depending on your address type.

Shipping Outside of the US
Class A Customs currently only ships within the US, we do not have any distributors.
Class A Customs does not / will not provide tax information, border or customs paperwork.

You can find more information on our Ordering and Returns Page located in the top menu.

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Answer provided by: Customer Service (9/26/2023)

Q: Will this tank fit 2012 American Coach Tradition?

Asked by: Steve Rhoads - 9/18/2023

A: Unfortunately, we do not have a list of vehicles, uses or projects people have done with our tanks.
Please compare the specs of the tank with your application and determine if tank will fit your needs. Check with online groups that have your same vehicle to see where they have found tanks.

If you are trying to replace a tank that you do not see available on our Water Tank List an online search may help you find the tank you are needing.

Look at current tank to see part #
Vehicle make and model #
Vehicle paperwork listing tank information

*You may not be able to find the same tank, especially in older units.
*You may not be able to purchase from the tank manufacturer unless you are a builder/dealer.

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Answer provided by: Customer Service (9/26/2023)

Q: What are the under carriage mounting options for this tank.

Asked by: Gary - 3/31/2025

A: Class A Customs "J" Mounting Brackets can NOT be used with tank.

You can find more information on Bracing and Supporting Water Tanks on our Blog Post: https://www.classacustoms.com/Bracing-and-Supporting-Water-Tanks_b_50.html

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Answer provided by: Customer Service (4/1/2025)

Q: Do these tanks come with a tank-sprayer option?

Asked by: Shell - 7/1/2025

A: This tank does not come with the tank sprayer option installed.

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Answer provided by: Customer Service (7/9/2025)

Q: Do these tanks come with a cap? I recently purchased one and it did not come with one.

Asked by: Evelin Martinez - 8/27/2025

A: The tank comes with the outlet, the tank does not have any inlets installed, customer will do this.

You can find more information on this on the Preparation & Installation Tab on the product page.

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Answer provided by: Customer Service (9/4/2025)

Q: Just would to make sure on measurements

Asked by: Jaime Cortez - 1/2/2026

A: Please click the first photo on this item listing, it will enlarge and has measurements. Thank you.

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Answer provided by: Administrator (1/5/2026)

Questions about this item? Ask here.

Installed Outlet Options

3” ABS Female Pipe - outlet can not be moved

1.5" ABS Female Pipe - outlet can not be moved - Due to the smaller outlet this tank is for dirty water from shower, handwashing, dish-washing - DO NOT use for human waste

Connecting Pipe & Dump Valve

From the ABS outlet that is installed in the tank run PVC Pipe or ABS Pipe to the outside of the trailer, a dump valve is added to the piping.

Pipe is connected to the ABS installed fitting in the tank with glue. You do not need to tighten the clamp that is on the ABS Fitting, this is used when the ABS fitting is installed into the tank and does not help secure your piping, over-tightening this clamp will damage ABS fitting and tank

Dump Valves

Dump Valves do not hook directly to the ABS fittings, the ABS Outlets are female fittings and the dump valves are also female fittings, you will need a pipe to fit inside of the outlet and dump valve in order to make the connection.

We do not sell glues, example only Oatey 4-fl oz Green PVC/Abs Transition Cement

Inlet & Vent Installation

Class A Customs Waste Water Tanks only come with the ABS outlet installed, the end user will determine where the inlet and vent will need to be placed and install.

Grommets are not food safe so can only be used for Gray or Waste Water use they are available in sizes 1.5" and 3", no adhesives are needed for use.

Uniseal Fittings are food safe and can be used for Fresh, Gray, or Waste Water use, they are available in size .5" to 3", no adhesives are needed for use.

Use correct size hole saw bit in order to drill a hole in the tank, smooth tank edges, and place Grommet or Uniseal in hole. Piping is then placed into fitting with no glues or adhesives necessary.

Mounting & Bracing

Some of the Class A Customs Waste Water Tanks are built with a "lip" on the tank. Tanks can be hung by this lip, it is recommended to make a shelf to slide the tank lip into.

You will need to brace the tank on all sides to prevent movement of the tank.

Brackets or Strap Systems Due to the variety of installations we do not carry brackets or bracing systems. Do Not hang by ratchet strap, this is too thin and will not adequately support tank.

Water Tank Monitor System

RV Monitor Panels allow you to monitor the amount of fluid in your water and waste tanks along with the battery power level. Typically only one monitor panel (2 tank or 3 tank) is needed per vehicle/unit and 4 Probes per tank.

To check fluid levels, press and hold the button designated for the tank and read the level indicators on the panel. Sometimes, residue on the sides of a tank, or water with a low mineral content will give a false reading.

Check the levels occasionally when you are sure of a tank’s contents and compare it to the reading on the monitor panel.

Installation Help Step-by-Step

4 Probes per tank needed

3/8" drill bit needed Measure and mark installation points before drilling. After drilling be sure to remove any burs from hole. Do not over-tighten probes.

Tank harnesses included with monitor panel. Customer will need to provide the extra wiring to run from the tank harness to the monitor panel. View wiring diagram for wire gauges ( 20 AWG / 14 AWG)

RV Waste Tank Removal and Installation Video

Manufacturer Warranty
Class A Customs, LLC Manufacturer Warranty covers manufacturer defect on manufacturer installed fittings and tank workmanship.

Inspect tank and all fittings before beginning installation, there is a 14 (fourteen) day time period to report any damages once you items are received. Cross-thread and thread damage is not covered once you have installed a connecting fitting into the tank fitting.

Warranty does not cover tank or fitting damage resulting from tank or fittings plumbing being jarred, moved, cracked, cross-threaded, damaged threads from use, and/or fitting punched from tank. Such damage is due to plumbing being moved and/or tank being jarred causing unavoidable damage beyond manufacturer control or responsibility.

Warranty does not cover tank or fitting damage due to customer improperly venting tank.

Warranty does not cover damage to tank from weight being on tank or tank being compressed by outside forces, example, tank being buried underground causing collapse; tank being compressed under boat.

Warranty does not cover damage to tank or fittings due to weather related incidents, example, tank freezing or being in excess heat/sun expose.

Using Class A Customs, LLC Fresh/Gray Water Holding Tank for any purpose other than fresh or gray water storage will void any/all warranty.

Using Class A Customs, LLC Black/Gray Waste Water Holding Tank for any purpose other than black (human waste) or gray water storage will void any/all warranty.

Using any Class A Customs, LLC water tanks for fuel, chemical or other storage voids warranty.

30 Day Return Policy
Some items are nonreturnable and include but not limited to:
All Fuel Pumps
Electrical Items
All Water Pumps

Customer will need to return all merchandise in new, unused condition and packing materials if available.
To return item customer will need to pay return shipping. Packages refused or return to sender will not be delivered back and no credit/refund will be issued.
Original Shipping is non-refundable, 20% Restock fee will be charged for all orders.

Returns c/o Class A Customs
1130 County Road 6 West
Elkhart, IN 46514
Phone: 574-206-0101

Include a copy of original purchase receipt and write order number on each box
Save the tracking numbers for your records, we are unable to search for a package online without tracking numbers.

Return Process
This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes to return the correct item. We'll notify you via e-mail of your refund once we've received and processed the returned item.