Bathroom faucet

[Frank64]

I have an issue with my hot water bathroom sink faucet in my 2019 3791RD. I have noticed a minimal amount of water in my storage space below(not in cabinet). I can inspect this area for a couple of days with no sign of any water. I have run a bead of silicone caulking around the faucet itself. Once in awhile I will get a small puddle about the size of 2 tablespoons of water. Then not see any evidence for a while. I have seen a few drops of water on the hot water (red) line
in the storage space. I have checked up under the sink nothing.
I thought about dismantling the hot water faucet and replacing the gasket
The picture I included has a small looking set screw.
I am looking for suggestions from the forum for troubleshooting ideas and input has to the proper tool I need to remove set screw
Thanks
FranK64

[mlh]

My suggestion is if you are having any problem with it take it out and throw it away and get a good one.
Lynwood

[Frank64]

That’s what my wife said

[DQDick]

Unless you can trace it back to the faucet it'self check the backflow preventer which is usually under that same sink. It's a black thing that has water coming to it and then going back under the cabinet. They are known to leak and it will only happen when you flush the black tank.

[Frank64]

Hey DQDick
This could be the culprit. I emptied my tank this morning.
I will empty my tank tomorrow and see what happens will keep you posted
Is the back flow preventer designed to be removed or is it glued in place

[Texan]

These faucets can be replaced with a residential faucet such as Delta or Moen from Home Depot or Lowes. I replaced mine several years ago.

[Frank64]

Thanks for the info

[DQDick]

Originally Posted by Frank64

Hey DQDick
This could be the culprit. I emptied my tank this morning.
I will empty my tank tomorrow and see what happens will keep you posted
Is the back flow preventer designed to be removed or is it glued in place

They can be replaced. We've always removed ours and used shark bites to connect the two tubes. We then use an external backflow preventer intended for use with a garden hose on the outside of our rig.

[Frank64]

Good advice will keep this in mind (shark bites)
Will keep u posted

[RMcNeal]

I had the same thing on our 2019 3791RD. Turns out the water was coming from the vacuum breaker/backflow preventer under the sink for the black tank flush. These plastic things are apparently notorious for leaking, so I removed it and just use shark bites to join the two pipes. The drips of water I was seeing usually ended up in the basement passthrough directly under the vanity where the drain pipe comes through the floor.
Sorry, Dick beat me to it. Same as what he said.

[Camp CA]

Same thing happened after winter camping in Lake Tahoe on year..............faucet froze up and after thawing they leaked. Ended up replacing all the faucets.

[twindman]

I had a leak too and fixed it without totally removing the backflow thing. On mine, the backflow valve could come apart (don't remember if it screwed or how). It had a small plastic marble in it that would prevent flow one direction. I just took the marble out and it is fixed.

[Frank64]

Hey DQDick
You were right it was the back flow preventer. I removed it and installed shark bite.
No more issues

Appreciate everyone’s input

[Rsmarlow82]

I’ve read with keen interest this discussion. As I read it, owners have experienced water Leaks in the storage area directly below where the water lines go to the bathroom sink. I have the same problem, and thought the PEX fitting(s)were peaking and getting ready to replace, but now rethinking that move.
1: what are shark bites ?
2: what is purpose of the back flow lines for the black tank , and are they necessary ?
3: I installed a check valve on the line used for flushing the black tank

Thank you for your responses

[3791RD]

My money is that it's the vacuum breaker... I have replaced mine twice... even carry a spare

[RMcNeal]

Originally Posted by Rsmarlow82

I’ve read with keen interest this discussion. As I read it, owners have experienced water Leaks in the storage area directly below where the water lines go to the bathroom sink. I have the same problem, and thought the PEX fitting(s)were peaking and getting ready to replace, but now rethinking that move.
1: what are shark bites ?
2: what is purpose of the back flow lines for the black tank , and are they necessary ?
3: I installed a check valve on the line used for flushing the black tank

Thank you for your responses

Shark bites are push on fittings for Pex and various other pipe and tubing.
The back flow preventer stops black tank waste from being introduced into the water supply. Very unlikely, but just a precaution.
A check valve will serve the same purpose as above if installed correctly. Is it a check valve or backflow preventer.

[Moondragon]

Don't forget that Montana usually forgets to finish the plumbing when they build them. My 2006 Mountaineer bathroom sinks leaked like crazy into the storage compartment until I went under the sink and actually tightened both supply lines. On my 2020 MHC, the island sink drain lines were kind of in the right place, just not connected to each other.

[Frank64]

I agree Moondragon. I found a couple of fittings, sink drains that were not completely snugged up

There are plenty of things to do with your camper always something to work on

[BuilderBob]

I agree with Linwood and DQDICK. the back flow valve has been a real problem on all brands. On the Montana's it under the bath sink.

[whutfles]

The backflo preventer will leak a small amount of water if you leave the backflush connected to the water supply and just turn off the outside faucet. As the water pressure decreases in the backflo line inside the RV, a small amount of water will seep past the valve. Disconnecting your hose from the source and allowing the water do train back out of the hose will prevent this.