question about sewer flush on my 5er

[lspencer001]

we have a 1998 carrie lite. this is our first time having a sewer flush system on any camper we have owned. I tried to use it a few times but when you hook the water up to it and open the drain valve nothing comes out and when you disconnect the hose there is a lot of back pressure that sprays when you unscrew the hose. I traced the line and it doesn't go straight to the tank. it from the outside connection it goes up under the bathroom sink and into some valve or something, not sure if it is a check valve or like a burp valve or something, then it goes back down into the tank. I unscrewed the line coming out of the valve and it was dry as a bone so I know that no water is getting past. is it worth looking into it more or should i just leave it the way it is now. that valve is a big brass 90* valve that has a silver cap on it and has what looks like a water regulator coming out of it that connects to the line going to the tank. sorry for a long post.

[Skip426]

The back flow , check valve, seems to be common to all, black tank flush systems. It's to keep an overfull tank from backing up to the water bay.
At least , it's not leaking under the counter, that's how they usually fail.
You can price one out and decide if you want to repair the system.

Edit: I see " jesilvas " has post the correct name , of the part , I knew I'd get something wrong.

[jesilvas]

Originally Posted by lspencer001

we have a 1998 carrie lite. this is our first time having a sewer flush system on any camper we have owned. I tried to use it a few times but when you hook the water up to it and open the drain valve nothing comes out and when you disconnect the hose there is a lot of back pressure that sprays when you unscrew the hose. I traced the line and it doesn't go straight to the tank. it from the outside connection it goes up under the bathroom sink and into some valve or something, not sure if it is a check valve or like a burp valve or something, then it goes back down into the tank. I unscrewed the line coming out of the valve and it was dry as a bone so I know that no water is getting past. is it worth looking into it more or should i just leave it the way it is now. that valve is a big brass 90* valve that has a silver cap on it and has what looks like a water regulator coming out of it that connects to the line going to the tank. sorry for a long post.

The valve under the tank is a vacuum breaker. Common problem. Replace the vacuum breaker and the cone seals and you'll be good I bet.

[mel s]

Originally Posted by lspencer001

we have a 1998 carrie lite. this is our first time having a sewer flush system on any camper we have owned. I tried to use it a few times but when you hook the water up to it and open the drain valve nothing comes out and when you disconnect the hose there is a lot of back pressure that sprays when you unscrew the hose. I traced the line and it doesn't go straight to the tank. it from the outside connection it goes up under the bathroom sink and into some valve or something, not sure if it is a check valve or like a burp valve or something, then it goes back down into the tank. I unscrewed the line coming out of the valve and it was dry as a bone so I know that no water is getting past. is it worth looking into it more or should i just leave it the way it is now. that valve is a big brass 90* valve that has a silver cap on it and has what looks like a water regulator coming out of it that connects to the line going to the tank. sorry for a long post.

lspencer001
Does the device under the sink look like this? :
https://www.google.com/search?q=vacu...52%3B250%3B292

If so it is a "vacuum breaker" to prevent the contamination of the incoming fresh water supply.
I suspect that that vacuum breaker is malfunctioning.

Any big box store plumbing department will/should have a replacement.

Mel
'96 Safari

[jesilvas]

A vacuum breaker is to break the vacuum, and allow and water in the lines to drain out and be replaced by air, so that the lines do not freeze.

[wa8yxm]

First, the most common "Flusher" systems are nothing more than a spray nozzle.. Holding the hose over the toilet while holding the flush valve open is just as good.

The "Back pressure" is simply the vacuum breaker draining back on it's intake line. Nothing to worry about, only fresh water here, no waste.

[lspencer001]

ok thanks all. I think that I have fixed it. the line comes up under the sink and goes to the vacuum breaker and then goes straight to a check valve. I took the check valve off and it was clogged with pine needles (there was no screen on the outside). I checked the breaker and the plug seemed to move freely and the check valve is now working like it should. I put it all back together and turned the hose on and the breaker and the check valve were humming and when I opened the toilet I could hear water running. fingers crossed it is fixed.

[mel s]

Originally Posted by jesilvas

A vacuum breaker is to break the vacuum, and allow and water in the lines to drain out and be replaced by air, so that the lines do not freeze.

I agree they allow the water in the lines to drain out.
However, the reason that vacuum breakers are required by most/all? plumbing codes is because they prevent the siphoning of contaminates into the fresh water supply, (thereby preventing contamination of the water supply)
Mel

[jesilvas]

Originally Posted by mel stuplich

I agree they allow the water in the lines to drain out.
The reason that vacuum breakers are required by most/all? plumbing codes is because they prevent the siphoning of contaminates into the fresh water supply, (thereby preventing contamination of the water supply)
Mel

But that's also why there is a completely separate flush line, to prevent that risk altogether.