Gray water tank-345 motorhome.

[Connie Smith]

Does anyone know how to drop and inspect a gray water holding tank on a 1989, 345 motor home? I need help.

[swebster]

Carefully! Before you drop it....what is the problem?

[Connie Smith]

There is a leak coming from somewhere "on top" of my gray water tank. I can't see it, and can't insert anything into the top area to determine where it's coming from. In fact, I can't even "imagine" how the tank connects to the internal drain system. I need to drop the tank to inspect it. I have attempted to do this. Was able to remove the side and front tank supports. There are no supports for the rear, unless it relies on the dump valve and related pipes, which I doubt. I can't make it go forward or back or down. I'm thinking that perhaps, I may have to remove the dump valve and related pipes in order to slide the tank rearward. I hate to do this, because that involves a seperate project to re do the dumping system.There must be some coupling system on top of the tank that relies on some directional pressure to keep it tight. I've tried to get some guidance from the Airstream folks, no results. I've also gone hunting for a repair manual. Same result. Any insight would be appreciated. Ben Smith.

[87MH]

Originally Posted by Connie Smith

....... I may have to remove the dump valve and related pipes in order to slide the tank rearward. I hate to do this, because that involves a seperate project to re do the dumping system....

Ben:

RE the dump valve removal -

In order to actually drop the grey water tank I think the dump valve will have to be removed....this is not quite as bad as it sounds.

The Thetford valves "split" for removal - the bodies are together by about 8 screws - remove the screws and the downstream portion of the valve comes off - the tank portion stays attached to the tank.

Rebuild kits containing seals and slide valves are available for rebuilding the valve when you go back together with it, but it is almost as cheap to buy a new valve and strip the new valve for parts as it is to purchase a complete kit.

Does the tank leak when full, or just when fluid is draining into it?

[Connie Smith]

Disassembling the dump valve sounds good! I thought of that, but was reluctant to proceed until I got some reinforcement. You just did that. Thanks much! As to how much and when it leaks - - for certain, it doesn't leak with just a low amount of water, say, about a fourth. But, from about halfway or more, I notice it dripping after I've driven. I think it probably "sloshes" up to some exit point, then find it's way out. I did one test while stationary at a camp site, put a substantial amount into the tank, maybe three-fourths, and didn't see a leak. It really sounds like the upper-most fitting is not "fitting" properly. I wish I knew how it was connected to the interior drain pipes. Any advice I've tried to solicit from "authorized" service people results in practically no useful information and a declaration that they'd have to "take a look at it." Thanks again. Ben.

[balrgn]

I don't know if this will help, attached is a photo of my valve piping. I needed to remove it to do some floor repair. I did a rebuild by removing the parts from a new valve. Everything disassembled with no problem. If you remove the piping you may want to use a heat gun (or hair dryer) to soften the caulking. Good luck

[74Argosy24MH]

Originally Posted by Connie Smith

I wish I knew how it was connected to the interior drain pipes.

This is the top of the gray tank in my 74 Argosy. The vents and drain pipes slip into the flanges and are clamped with hose clamps.

John

[Connie Smith]

Hey, swebmaster, 87MH, balrgn and 74argosy. I want to thank you guys for taking the time to respond in my "hour of need". You provided some encouragement and some useful tips. It's nice to know I'm not out there alone - - at the mercy of the "real problem solvers". I'm going to go back at it over the week end. I will let you know how it comes out. Thanks again. Ben.

[87MH]

Ben:

Just looked up the (dis)assembly in the owners manual.

After emptying both tanks,

First, Remove all the bolts connecting BOTH of the valves to BOTH of the tanks - remove manifold as an assembly.

Second, Loosen hose clamp on inboard drain line adapter - *

* - Can't help you on this one - the drawing shows the "Inboard drain line adapter" as at the top, almost to the rear (but on the inboard side), at a 45 degree angle angled to the curb side.

Third, Support tank and loosen the three bolts on the inboard support bracket.

Fourth, Lower inboard side of tank just enough to allow the hose clamp to be loosened on the outboard drain line adapter. This connection is ON TOP of the tank, toward the drivers side, just behind the Gate Valve.

Fifth, Pull tank toward the center of the vehicle to free it from outboard support bracket.

Sounds simple enough!

[balrgn]

Originally Posted by Connie Smith

Hey, swebmaster, 87MH, balrgn and 74argosy. I want to thank you guys for taking the time to respond in my "hour of need". You provided some encouragement and some useful tips. It's nice to know I'm not out there alone - - at the mercy of the "real problem solvers". I'm going to go back at it over the week end. I will let you know how it comes out. Thanks again. Ben.

If you'd like to see what I ran into on my '75 feel free to visit my webpage.

http://home.comcast.net/~balrgn/Airs...oject_2004.htm

[87MH]

Originally Posted by Connie Smith

......It's nice to know I'm not out there alone - - at the mercy of the "real problem solvers". I'm going to go back at it over the week end. I will let you know how it comes out.....

Ben -

I put a bit more thought to your "leak" last night, and could not get Steven's question (swebster "...Before you drop it....what is the problem?") out of my head. (I think Steven had some pretty good insight here.)

There is a plethora of possibilities for water leakage in this area.

First and foremost - the water heater. The water heater is located under the rear dinette seat - the manifold is the standard AS grey plastic, and has been known to fail - (I repaired mine with new PEX after a Tee cracked). The WH manifold on the inside of the coach actually has a drain valve that apparently drains right on top of the grey water tank (on mine, the valve certainly looks as if it is factory installed) this valve, like the other potable water drain valves is pull to open, push to close. This WH drain valve is not documented in the owners manual. Besides the WH manifold, other WH leaks could be: leaking tank, leaking burner tube, leaking "pop off" (pressure relief) valve, or even the engine water circulation system in the WH.

Other sources of leaks manifesting themselves in the area of the grey water tank are the lav washbowl, plumbing, and drain system (the wash bowl actually drains into the Black Water tank), the fridge, leaking fridge vent, leaking fan vent, AC seal to roof, the pan of the AC itself (the AC condensate from the rear AC drains between the drive axle and the tag - but if the line is plugged the water could well follow the exterior of the hose and find a way to exit the floor anywhere in this area). Perhaps even rain water is puddling in the AC pan and when you pull out on the road it "sloshes" and eventually ends up on top of the grey tank.

I guess what I'm saying is that the water could really be coming from just about anyplace.

I might suggest that prior to actually pulling the GW tank you give it a really good operational test - like filling the thing all of the way up - even to the point of water backing up into the shower - I would hate to have to pull the tank (AND the nasty Black Water Valve) if your GW tank is not the source of the leak - you might even want to drive the thing around the block with the tank full just to be sure (be careful you do not throw water out of the shower pan).

I know first hand that the potable water lines on the unit could leak sometimes (excess pressure, vibration), and be tight as a drum at other times (if you can't find the leak, you can't fix it).

Also suspect are any place that rain water could leak, puddle, and finally make an exit when the coach is in motion.

Please post here on the Forum your results - whatever you try first - as most likely at least some of us will experience your same problem sooner or later.

[Connie Smith]

"WOW" , Dennis! Looks like you covered a lot. I'm going to take your tip about assuring myself that it is actually coming from the gray water tank before I try again to drop it. I'm going to put some food coloring in the tank and then fill it with water as you suggested. I'll let you guys know how things turn out. Thanks again. Ben Smith.

[ALANSD]

On my 280 a shower leak at the back of the valve came out about 3 feet away. Like what Dennis was saying the leaks will travel to the easiest exit.

[Connie Smith]

I thought I’d submit an update on my gray water tank problem. With a lot of effort and a lot of advice, I finally got the tank off. 74Argosy24MH was right - - two hose clamps had to be accessed. Then, after I got one side off, the tank it wouldn’t drop enough to allow access to the other side because the tag axel was in the way. Access to the clamps was a real problem, especially for the one on the roadside. Had to cut a new hole in the floor for that one. The information I got from 87MH was invaluable. The tip from "balrgn" about using a hair dryer, worked well. After I got the tank off, I couldn’t find the leak right away, and began to think that the leak could be elsewhere, which were possibilities raised by 87MH and ALANSO. Finally though, the leak showed itself. It was a small crack about 7 inches long, just above the roadside support area. In fact, someone had obviously attempted to repair it by smearing on “some stuff” (probably the guy who owned it before me, so he could sell it). Now, I’m shopping for a new tank to determine if attempts to repair this one would be justified when compared to the price of a new one. I’ll let you know later how this turns out, if you’re interested. Again, thanks to all of you for your help, and also thanks to one of the customer service guys (Randy McNeely) at Airstream. Ben Smith.