City water leaks behind flange

[xben]

Hi,

I just replaced a broken city water fitting. While doing a leak test, I noticed there is a little leak behind the flange (between the flamge and the RV wall) when I disconnect the hose from the RV at first (before disconnecting the end from the tap). Otherwise, if the hose is disconnected from the tap first, there is no leak at the RV end. It looks like the pressure needs to be released before disconnecting the hose from the RV to avoid that leak. I tried with 2 fittings and it does the same behavior. Is that normal?

Thanks!

[Argosy]

Doesn't the hose leak at the tap end when you loosen it first? The pressurized water is going to escape wherever it can.

[xben]

Yes it does, but a small amount also leaks behind the flange. I can see it clearly as it is still hanging (not fixed to the RV yet). If the pressure is released from the tap end, no leak.

[Persistent]

RV city water connector should not leak before or when disconnected. Vacuum break connector may.

Post a picture for better advice.

[xben]

See the attached image.. It is a bit dark but we can see a lot of water dripping at the bottom of the flange. After a deeper analysis, it seems the water is passing through the flange by the swivel connector, even if there is an o-ring. It is probably not tight enough but I can't figure out how to make it more tight.

[Old-Biscuit]

That is a lot of weight hanging on the hose side connection

If you can not get it tight enough now (not installed) you will never get it tight enough when you attach it to side of RV

I have a 90* brass elbow with shutoff valve connected to my city water inlet
It STAYS in place....so I tightened it using pliers
When using hose I connect it to the end

[xben]

It only leaks when I disconnect the hose from the inlet. I disassembled it and without the flange, I clearly see the water goes between the check valve and the swivel nut. There is no washer there, so I suspect that when disconnecting the hose, the accumulated pressure wants to escape where it can, and this is one of the available spots.

[Old-Biscuit]

Buy another one........

Water leaking inside RV possibly between sidewall WILL destroy it

[hohenwald48]

You can just replace the whole thing for less than $20.

Sent from my SM-S127DL using iRV2 - RV Forum mobile app

[Argosy]

The check valve is cross threaded into the swivel nut.

[xben]

There is no thread between the check valve and the swivel nut.

Anyway, I replaced both parts by 2 new brass ones... Which also leaked following the same pattern. Replaced them again, leaked again... I did a demonstration to the store with 2 new ones (i.e. 7th & 8th parts) that also leaked. They were speechless. I'm pretty sure this is a design flaw, so you better check yours. Remember they only leaked following a specific sequence.

[Argosy]

There is thread on the check valve and it is cross threaded. Most likely it also needs a cone washer to seal.

[xben]

This is not where it leaks, go back to top and read carefully

[MrMark52]

Sounds to me like there is a vacuum breaker in those parts - and vacuum breakers will dump water, either when first pressurized and, when there is a higher pressure on the downstream side than the upstream side (it’s the whole intent of a vacuum breaker! - to prevent water backing up into the potable water source system).

Not an easy solution as the vacuum breaker really needs to be there, or somewhere where water hooks to the coach (some parks might not let you connect, or force you to disconnect if there is no means to prevent contamination of their water system from your coach in the event of a water system failure).

Best solution I can think of is to open a sink faucet IN the coach before turning off the water supply TO the coach - that allows the coach pressure to bleed down as system pressure bleeds off and the vacuum breaker won’t open to dump water.

Or, find pieces/parts to eliminate the vacuum breaker and use a vacuum breaker on the outside of the coach where the hose connects.