Water Leaking from Underbely after Black Tank Flush GD 297rsts

**LetsGo1965** · 11-01-2023, 07:13 PM

We are fairly new to owning a travel trailer and we have a 2023 GD 297rsts. This weekend we were packing up to go home from a trip and we flushed our black tank. Once we hooked the trailer to the truck and took the trailer off the leveling blocks we noticed clear water pouring out from underbelly of trailer, where the grey and black pull handle lines enter the underbelly. Does anyone know the cause of this water accumulation? Thanks in advance......

**Probe1957** · 11-01-2023, 08:36 PM

You certainly need to figure this one out. Does your water pump come on for no apparent reason?

**LetsGo1965** · 11-01-2023, 09:00 PM

No, the water pump does not come on. The trailer came to us "new" with mislabeled pull levers (black was grey, grey was black, etc) and miscalibrated sensors on the tanks. We recently took it in to the dealer to get all that straightened out, and this was our first trip since that work was done. I'm wondering if they didn't screw something back in correctly or some sort of seal is broken. It is still under warranty, so guess we'll be taking it back to dealership.

**Hoopy Frood** · 11-01-2023, 09:24 PM

One possibility is the vacuum breaker on the black tank flush has failed and allowed water to run inside the trailer. Did you happen to notice if there was a solid strong flow of water while the black tank flush was running? The vacuum breaker is usually plastic and is a known failure point, and not just on Grand Design trailers.

**Probe1957** · 11-01-2023, 09:25 PM

We just traded for a 297RSTS. Picking it for a shake out camp on Tuesday.

**NB Canada** · 11-02-2023, 03:00 AM

It could be from anywhere

I would try to duplicate the situation at home and see what you find

Dropping the covering underneath isn’t that hard and will likely show the issue

From most posts on here it could be months before your dealer looks at it. Maybe your dealer is different

Good luck

**FT4NOW** · 11-02-2023, 03:31 AM

I'm curious how the dealer calibrated the tank sensors. They are essentially probes that get installed in the tank by drilling a hole in the tank and then placing the sensor in each hole. If they relocated the sensors, they would have had to fill the hole with something, if not done properly or didn't cure enough before use, it could be a leak point. As far as I know, there is no calibration of the sensor unless it was incorrectly wired from the factory.

**reubenray** · 11-02-2023, 04:36 AM

Originally Posted by Hoopy Frood

One possibility is the vacuum breaker on the black tank flush has failed and allowed water to run inside the trailer. Did you happen to notice if there was a solid strong flow of water while the black tank flush was running? The vacuum breaker is usually plastic and is a known failure point, and not just on Grand Design trailers.

This happened on my soon to be traded in Forest River Vibe. I noticed water the first time below the vanity sink. The second time it was dripping from the bottom. I replaced this with a 90 degree brass elbow.

**Scott'n'Wendy** · 11-02-2023, 04:40 AM

Originally Posted by FT4NOW

I'm curious how the dealer calibrated the tank sensors. They are essentially probes that get installed in the tank by drilling a hole in the tank and then placing the sensor in each hole. If they relocated the sensors, they would have had to fill the hole with something, if not done properly or didn't cure enough before use, it could be a leak point. As far as I know, there is no calibration of the sensor unless it was incorrectly wired from the factory.

My guess is it was the full sensor was in the 3/4 spot...or something like that.

To the OP, if the dealer was just working on the tanks, it would be very likely they caused the problem.

**BoredWeasel** · 11-02-2023, 07:40 AM

Originally Posted by FT4NOW

I'm curious how the dealer calibrated the tank sensors. They are essentially probes that get installed in the tank by drilling a hole in the tank and then placing the sensor in each hole. If they relocated the sensors, they would have had to fill the hole with something, if not done properly or didn't cure enough before use, it could be a leak point. As far as I know, there is no calibration of the sensor unless it was incorrectly wired from the factory.

LOL I was thinking the same thing. There is nothing to calibrate, unless they took a wand down the commode and sprayed all the paper off the walls of the black tank.