Thetford toilet leak

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Thetford toilet leak

Postby dfuehrer » Mon Oct 01, 2007 4:37 pm

Hello everyone,

I have a Thetford Aqua-magic IV toilet in my 1990 Shasta. At least that is what I THINK I have. I got no manuals when I purchased mine RV. I found the PDF manual on-line at their web site, and downloaded it. It looks like my toilet. Anyway, the water supply to the toilet leaks.

It appears that it has for some time now, as there is a DPO repair, consisting of a thin piece of plywood at the rear portion of where the thing bolts to the floor. Now it is slightly taller (about 1/4" at the rear) and moves when you sit on it! This sets up more problems. The water supply line is only so long, with no give to it. So the rest of the DPO's fix was to add in a double threaded plastic piece of pipe to increase the length, and thus make everything bolt up, right?

WELL... with the thing tending to want to move, it was only a matter of time until trouble would follow. Where the supply line goes into the tiolet, on the bottom, in back, it began leaking there when the onboard pump would reach pressure. I haven't ever been brave enough to hook up to city water pressure.

I thought I had repaired the problem, by installing a length of 18" flexable hose between the stool and the supply line. Wrong!

The last time out, the pressure blew the line out of the bottom of where it is supposed to attach to the toilet! For the life of me, I cannot see how it ever held any pressure to begin with! there seems to be no way for this assembly to bolt to the toilet itself. It just slipped right out. Only the ridgid supply line was holding it in place to begin with, and my repair allowed it to blow out under pressure.

So my long winded question here is a simple one... Can this toilet be repaired, or should I start looking for a new replacement? I know that I should also look at the condition of the floor beneath my carpet around the base of the stool as well!

Thanks in advance for your wisdom,

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Joined: Fri Jul 20, 2007 3:20 am

Postby Marty in TN » Mon Oct 01, 2007 5:04 pm

Don: I've been riding the same type horse you have with seepage, drips and actually having the feed hose blow off the commode valve while hooked to city water. Now that caused a mess to be sure.

Here's what I learned and by the way, I had to make an extension for hook-up because I put a three inch riser under the commode.

First off, make certain that the threads on the commode valve have not been stripped, even a little bit. Secondly, don't use commercial connectors like getting from Home Depot or Lowels. Got to a RV supply place and get a RV water connector. Commercial connectors don't give you as many threads as the RV type and secondly with the commercial connectors, everything has to lined up perfectly to preven leak/seepage.
Clamps? Having to use a clamp to lock a water pipe onto the connector, pre-warm the water pipe with a hair dryer to soften it up a bit. Makes it easier to get a good solid clamp to prevent seepage or leakage at that area.

As for the control valve, unless the threads have been stripped, I don't believe you'd have to replace it unless it's been damaged or is leaking in an area you couldn't repair. Commode its self, not unless it's been cracked or broken. I would pull it and check to flooring underneath and repair if necessary.

I think I have my problem resolved but then again, with water and the fact that I hate any type of plumbing, who knows.

Marty in TN
Posts: 348
Joined: Sun Sep 04, 2005 7:22 pm

Thanks for the reply!

Postby dfuehrer » Mon Oct 01, 2007 5:20 pm

The "Home Depot" supply extension I added isn't where it blows appart. The entire water valve assembly pushes out unter pressure.

Where it all goes sour for me, is the fact that there doesn't seem to be any type of fastner that keeps the water valve in place, except for the ridgidity of the water supply line itself! So I am not sure if I need to replace simply the valve, or the entire stool! Should the valve just blow appart like that?

From what I can see, the valve assembly runs around $45.00, a replacement stool starts at around $200.00.
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A pic of what I am talking about...

Postby dfuehrer » Mon Oct 01, 2007 5:51 pm

Can I attach a PDF sketch here, to show what I am talking about?
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Joined: Fri Jul 20, 2007 3:20 am

Postby Thomas Thibodeau » Tue Oct 02, 2007 1:27 am

The valve should be held in place by 2 screws, mine was when I replaced it this year.

Your screws could have rusted out if someone replaced them with the wrong ones or the plastic they screw in could be damaged.
It is a simple repair and the replacment valve is a little bit different.

Mine was seeping from the vacuum breaker.

All fitting should only be hand tight
Thomas Thibodeau
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Joined: Sun Sep 04, 2005 2:14 pm
Location: Hants Co. Nova Scotia

Postby Russ Chastain » Thu Oct 04, 2007 7:17 pm

You can try hosting the pdf file on another URL and then linking to it from one of your posts.
- Russ
Russ Chastain
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Joined: Tue Sep 06, 2005 1:33 am
Location: Florida, USA

Aqua Magic Iv

Postby thewiz » Fri Oct 05, 2007 2:51 pm

Don I had to pull my toilet because I couldn't get behind it to work on the valve.
When I got it out I discovered so much oxidation from slow leaking over time that I couldn't even remove parts to repair it.
I ended up taking a chain saw to it and put the parts into the garbage.
I went to this site and purchased a new toilet so now it sits higher, a plus for the wife. And, brand new so it probably will outlast us.
I sprayed silicone on the operating stuff before the install.
The prices are not very high and for something like a toilet that is sorta personal, this might be the way to go.
Here is the link. ... YAodxEJEXg
John in sunny Clyde, Ca.
Posts: 499
Joined: Mon Sep 05, 2005 4:18 pm
Location: Clyde, Ca. USA

Postby Carl » Fri Oct 05, 2007 4:31 pm

John, you are definately better off getting a new potty. Mine sprung a leak while I was on the road. I went to a local RV dealer in Jackson Michigan and purchased the rebuilt kit..$75.00. Then pulled the toilet, repaired it and it still will not hold water as it should. Should have gone the few extra bucks and bought a new one like you did. Oh well, hind sight is always better than fore sight. How did you find the floor under the toilet? Carl
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Joined: Thu Sep 08, 2005 3:59 pm
Location: Orlando Florida

Well, I did it.

Postby dfuehrer » Sat Oct 06, 2007 8:17 pm

I purchased a replacement water valve kit from a local RV dealership. It is kind of a dirty job, but I think it will be worth the effort.

Once I had the stool off, I saw just how mucked up the inside was! My pressure washer took care of that. I was careful not to damage any of the mechanism inside, just clean the gunk out.

I was glad that the kit came with a new bottom seal, as mine was in poor shape from movement. As it turned out, the old valve is OK. Just a poor design. The piece that the supply line attaches to is heald in place with a sort of internal plastic clip. The replacement valve is of a better design, and won't come appart under pressure.

Sure, a new toilet would have been a bit easier, but you can't beat the $28.00 I paid for the kit. Even on eBay, a used RV toilet is going for much more than that!

Thank you everyone, for the advice given here. It was very much appreciated, and helped me in figuring out what to do.


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Postby thewiz » Sun Oct 07, 2007 3:41 pm

The floor around mine was still OK, I was lucky.
I had the toilet off for about a week with a plastic bag in the opening.
Luckily we had just dumped so I used my flashlight to look inside.
The tank was very clean to my amazement.
The new higher toilet is sure a winner as it is easier to sit and get up. Of course we are older so any help is appreciated.......................
I didn't know people sold their old toilets on Ebay. What an interesting concept. Do they post the mileage? Barely used? low mileage?
Only used by a little old grandmother on weekends?
John in sunny Clyde, Ca.
Posts: 499
Joined: Mon Sep 05, 2005 4:18 pm
Location: Clyde, Ca. USA

Postby dfuehrer » Mon Oct 08, 2007 9:43 pm

Well there is one that states that it has never seen a pair of buns...

Seriously, after seeing how much gunk was inside of mine, I wouldn't want to buy someone elses dirt!

Next time, I will go with a new one!
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Joined: Fri Jul 20, 2007 3:20 am

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