2010 Keystone Montana 3400 5th Wheel, Drip -- Leak underneath

[CinnamonC]

Recently purchased a 2010 Keystone Montana 3400 which is currently parked in my yard in Bradenton, FL, with all systems hooked up. Today I noticed a small "drip" underneath the camper aft of the wheels away from where any of the tanks should be and opposite the drivers side. It is a constant drip and hard to determine where it is coming from but it appears that a small amount of water is pooling and causing the drip. Anybody have any ideas what's causing it and where it's coming from without taking the black covering off the bottom? The camper appears to be in good to excellent condition and has been well maintained. Ideas please!

[chuckster57]

Welcome to the forum

Your trailer is probably old enough that the coroplast ( black liner on the bottom) is held in by screws. You need to remove a few and then look inside. You may have to move and remove more in a different spot to locate the source of the drip.

[flybouy]

Have you checked inside the camper for a leaking waterline to a sink or the toilet? I would inspect inside the cabinets first, then start inspecting underneath. I use an endoscope that connects to my phone & tablet to look inside tight areas.

[CinnamonC]

Yes. I've checked everywhere inside and all seems to be nice and dry around all water lines. Thanks for your reply.

[Mikendebbie]

The fresh water tank could be in the rear. Look for a drain sticking out below the coroplast.

[RV Vacation]

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Your refrigerator in that area by chance? Have an ice maker? Have defrost feature?

Do you have access to the back of or under your refrigerator?

Good luck.

[JRTJH]

If I understand your original post, the drip is toward the rear of the trailer, aft of the wheels, on the passenger side of the trailer?????

If your floorplan that I found is accurate, your refrigerator is in the driver's side slide, the sink sits in an "island/peninsula" in the center of the trailer, over the axles ???

I'd first try to determine whether there is a fresh water leak from the plumbing supply lines. The easiest way to do that is to disconnect the city water hose, turn on the water pump and pressurize the system. The pump should run, then shut off. If there is an active leak in either the cold or hot water, with a "steady drip" (as you described) the pump should "burp" or "cycle on for a second then turn back off". It will do that repeatedly as the drip will cause a drop in water pressure and the pump will cycle to re-pressurize the water lines.

It may take half an hour, maybe an hour for the pump to cycle, it will depend entirely on how rapid the leak drops the pressure.

If, after a couple hours, the pump has not cycled, then I'd rule out the pressurized water system as the source of your leak and focus on either the gray tank and its plumbing or the refrigerator and the drain line that should be "routed out through the lower vent panel in the trailer sidewall"....

That drain line, if it is the original, is very likely to be brittle and possibly damaged. Its intended purpose is to drain the condensation that drips off the fins in the upper back wall of the refrigerator section. The white tray under those fins has a drain port on the left side (as you're looking into the refrigerator). On the back side of the refrigerator, hidden behind the pipes and the gas chimney, that corrugated hose connects that drain and is routed out through the vent panel. If that hose is crushed or broken, all that condensation is dripping onto the floor where the refrigerator is mounted, possibly running "downhill to the lowest part of the trailer" and then dripping onto the ground where you noticed the active drip.

I'd suspect either a split pipe in the pressurized plumbing or that drain hose on the refrigerator.

After you verify those, let us know and we can suggest the next steps....

[CinnamonC]

Thanks for your good information. I’ll get it checked out tomorrow with your suggestions and will update.

[dutchmensport]

JRTJH's suggestion is spot on to disconnect from shore water and fill your fresh water tank, then turn your water pump on and wait to see if it cycles on and off.

It takes only about 3 ounces (or less) of water dripping to turn the water pump on and off because there are no pressure tanks in RV's (unless one is added after market). So a very small drip will eventually cause the water pump to turn on. If the water pump does not turn on at all, that's right.... you have no leaks in the water pipe system anywhere. The water drip is coming from somewhere else.

You can eliminate the water pipes very easy this way, cost nothing but a little time and patients.

I agree with the refrigerator theory and the condensation drain line failure idea too.