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Toilet Leaks, Seals, and Repairs

Your RV toilet offers a place of privacy when the only other option is a campground bathroom or a tree. But what happens when your toilet springs a leak? Not only could you be faced with time-consuming and costly water damage to your RV, but you could slowly (or quickly, depending on the leak) be losing the water in your tank. Let's take a close look at toilet leaks, seals, and repairs.

How an RV Toilet Works

An RV toilet does not work the same as a residential toilet. A residential toilet has a water reservoir in the back that refills the bowl as it’s flushed down into the plumbing. An RV toilet has water that comes into it from a water line as you flush, and drops the waste and water into the black tank of the RV. There is a ball in the bottom of the RV toilet that has a seal on it that holds the water in the toilet and everything else in the black tank between uses. The flusher on the toilet will usually have dual purpose. Pushing it down will flush it, and pushing it up will add more water. Because there is a water line coming in and a seal that holds the water in the toilet, there’s the possibility of leaks from both areas. If you experience a leak, you first need to find the source and cause of the leak.

Determining the Cause of the Leak

Determining the cause of a leak is the first step to repairing it. It could be coming from a few different places, so you need to evaluate what the toilet is doing when it leaks and where the leak is going. First, figure out where the water is when it leaks.

Bowl is Absent of Water After Sitting

After using the toilet, if there is water in the bowl, and then it’s gone (after it has been sitting for a while), this means that it's leaking down into the black tank. While this isn’t an urgent issue, it could lead to some odors in your RV. The gasket under the flap in the bottom of the toilet is the cause of the leak and will need to be replaced.

Water is on the Floor

If the water is pooling on the floor, it’s coming from the water inlet. If it’s puddling on the floor while sitting, it most likely is a problem with the inlet fitting in the back of the toilet. If your toilet is leaking during the flushing process, then you have a problem somewhere in the flushing mechanism inside the toilet.


Now that you have determined the source of the leak, it’s time to get it fixed. Be sure to check your owner’s manual before you begin just to ensure the recommended method of repair. RV toilets can vary greatly, so always refer to your manual before doing any work.

Replacing the Gasket

If your gasket is leaking, you will need to replace it. No matter what brand of toilet you have, you will have to remove the toilet to get to it. First, make sure you turn the water off to the toilet or you’re going to get a little wet. You should also wear some protective gloves since you’re going to be dealing with the sewage system. Once you have the toilet out, you will see that what remains is the seal assembly. After referring to the RV's manual, pop the seal and its housing off. Go ahead and clean up the area while it's exposed as this is the only chance you may have to clean it. Replace the seal following the directions on the package for the replacement, as it may be a little different from the original one that was on the toilet. Reassemble the toilet and test it to make sure that it holds water. Once you have your new gasket in, there are some things you can do to prevent future leaks. Always make sure there is water in the bowl, as this will avoid the gasket drying out and cracking, which is the main reason for its demise. Another way you can keep it conditioned is by applying petroleum jelly to it. Put a thick coating of it on there after replacement and then every so often moving forward to keep it moisturized.

Replacing the Valve

If the problem is coming from the valve, you will need to remove the toilet just like with the gasket repair above, so make sure you turn off the water to the toilet. Once you remove the toilet, take it outside where you have plenty of room and light to inspect it. In the back of the toilet, you should be able to see the entire mechanism that flushes it. Look for wet spots to ensure you have the right replacement part. Repair kits for pretty much any toilet are available online. The Internet is also a great source for videos and tutorials that will walk you through the repair process one step at a time.

If you find that your RV's toilet is cracked, it's time to replace it. However, if the problem lies elsewhere, you can fix it in just a few steps and with just a few supplies. Don't let the "Ewww!" factor dissuade you from trying to repair a toilet problem on your own. Snap on some gloves, maybe wear some safety goggles, and show that toilet who's in charge. However, if the problem appears to be too big to tackle on your own or you'd just rather not get your hands dirty, then take your RV to a service center where they can get it working again in no time. You'll be back to enjoying all the fun camping activities you were looking forward to or making some delicious campfire panini sandwiches to refuel for the next day.

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