Water system Leak

[Dilly]

Hey guys,

I finally made it down to Austin TX from MN with my 1982 Avion 34v to continue my restoration in warmer weather. What a drive that was with shit brakes! Not moving again until i get the my brakes (truck and trailer) dialed in. I'll be making another post to get your thoughts on that. Anywho, I've got the new pump working and all the leaks in the pressure side taken care of, now it looks like I may have a leak in the drainage side. I ran the fresh water tank dry to flush out the nasty old water and I noticed a leak coming from the belly pan right above the axles. The grey water tank was my first suspect, but according to the manual, the gray and black tanks are aft, under the bathroom. Why would I be leaking at the axles on the driver side? Does anyone have a more detailed diagram of how the tanks and drainage system are laid out?

[KYAvion]

I don’t have a detailed diagram, but hopefully someone with your trailer can tell you exactly where your tanks are.

I assume the same leak occurs when running off city water?

[Dilly]

I don't believe so. The pressure side of the system couldn't be leaking because my pump shuts off like it should when the system is holding pressure(no leaks). Because of that, I feel like it has to be drainage. But with the tanks being at the rear it doesn't make much sense. One thought I have is that the grey tank is full and overflowing through the drainage pipe to the kitchen sink and is somehow leaking from there.

[KYAvion]

What I meant to ask is whether you notice the leak when connected to city water and running water down the drains.

So based on what you’ve said it sounds like your supply lines are all in tact, so as you said it’s likely a drain line somewhere or a crack in your grey tank. What happens if your grey tank valve is left open when running water down the drains? Does it still leak?

[silverloaf]

I don't believe so. The pressure side of the system couldn't be leaking because my pump shuts off like it should when the system is holding pressure(no leaks). Because of that, I feel like it has to be drainage. But with the tanks being at the rear it doesn't make much sense. One thought I have is that the grey tank is full and overflowing through the drainage pipe to the kitchen sink and is somehow leaking from there.

How is your trailer configured? Where's the bathroom located?

[Dilly]

Its a rear bath.

I was not connected to city water when I noticed the leak and unfortunately I am not in a location where I can drain the grey water tank.

[KYAvion]

Did the leak begin to occur once the grey tank approached full?

If the leak was in one of the drains leading to the grey tank, wouldn’t the tank now be empty?

[Dilly]

I believe that the tank was approaching full or was full when the leak started. I don't trust the tank level monitors at this point because I have not had a chance to really use the water system and verify that they are accurate. I am assuming that they don't work because everything so far has been broken. The monitors currently read: tank 1=1/4 tank 2=F fresh=E. That is actually right about where I think they should be now(assuming 1=black 2=grey), so maybe they do work.

I am assuming that the grey water tank is the low point of the system, so there was a leak in a sink drain leading to the grey tank, the tank would not leak unless overflowing. Maybe I wrong and the drain meets the tank at a lower point? Thats the problem, I don't have a diagram so its hard to diagnose. Im going to keep messing with it and I'll report back.

Can I drain my grey tank into the black tank? Is there a valve for this or maybe I can cap the dump spout and open grey and black dump valve until they equalize. Then I can see if the monitors work and I will know that the grey tank is at least half empty. Its is such a pain that I am not able to dump the tanks right now.

[KYAvion]

As I just reread my last post, I realized it didn’t make sense. Sorry.

The grey tank should be the low point. Yes, you could equalize your grey and black tank, but I don’t think there’s a good reason to do that.

Assuming your grey tank was full before the leak started to occur, it seems logical that the drain line leading to the tank backed up and began leaking somewhere. Ordinarily the tub will fill up when the grey tank gets too full, but in your case it came out somewhere else instead. Another possibility is someone drilled an overflow drain on your grey tank.

I think your freshwater tank holds 65 gallons and your grey water 30 gallons. Something to consider is that had the full 65 gallons of freshwater not been drained into the grey tank, you may not have ever noticed a leak.

[Dilly]

Hopefully you are right and this is a non-issue. I pulled some of the belly pan and was able to see that my tank configuration is different than stated in the manual. I can see that the tub drain is running forward towards the axles. Here is a photo of an 88 34xb with the floors ripped out showing the tanks, I believe this is how mine are laid out which explains why the leak is coming from the axles. I also do have plastic tanks which to me, seem less likely to be leaking than steel tanks. Now to figure out how and where to dump 35gals of disgusting grey water without moving the trailer! I really think that transferring some to the blank tank will help my cause, that way I can at least see if it still leaks when I send drain water to it.