Leaking tank

[Montana4two]

I know this has probably been covered before. We have a leak either from our galley tank or from a fitting on the tank. What is the best way to start checking to see if it is the tank that has a crack somewhere or just a fitting. Taking down the under-belly seems a huge job. We are full-time in our 2006 3400RL and leaving for Arizona in 4 weeks.
If we leave the tank open continuously draining into the portable blue boy there is no problem, but of course can't continue like this. As soon as it gets about half full the puddle starts

[bncinwv]

Unfortunately, the only way to know for sure is to drop the underbelly. I would think one of the inspection cameras might work, if it had a light source or infrared. A small hole could be cut in the underbelly and repaired with gorilla tape if that route is preferable. Of course when you identify the leak, odds are you will have to drop the underbelly for the repairs. My gut feeling is that if it is leaking when half full, it is most likely a cracked tank.
Bingo

[Montana4two]

Is this an issue with Montana's ? I see so e people have had multiple tank failures?

[Montana4two]

Is there a fix by repairing the tank or is it a replacement that is needed?

[bncinwv]

If the tank is cracked, replacement is usually the best option. There have been mixed results when trying to patch the tanks since they are constructed of a material that is not easy to repair. The tank failures are not necessarily a Montana only event, these same tanks are used on many rigs.
Bingo

[richfaa]

The underbelly on the 06 3400 is in sections and not hard to drop. We had ours down several times with 5 tank failures. Since you mention it leaks when 1/2 full you most likely have a split in a seam although all of ours failed at the inlet. If it is a split and you can see it you can repair it. Since you did not mention a Black tank smell you can count that out. The galley tank will also smell but not as bad as the black tank, the galley tank on the 3400 is right above the axles and not easy to get to and that section of the under belly is difficult to drop. If it is the galley tank the smell is unmistakable.

You might try to drop one side of that underbelly section and see if you can see the leak. That worked on the leaking galley tank of our 13 3402. Then if you can see it cut a hole in the underbelly in the area of the leak and do a repair. Leaking tanks are more common than we would like.

[Ozz]

The panel by the passenger side wheel needs to be dropped if it is the Galley tank. You can get the plastic tank repair kit on Amazon for around $30.00 if I remember correctly.
I made the repair, but.. you need to cut the drain line pretty close to the tank, install a rubber repair coupling with the 2 hose clamps, then further down the drain line cut it again, install another coupling, or the repaired crack will crack again. It needs the flex-relief.






Slide-show on it:
http://tinyurl.com/OzzHoldingTankRepairs

[Montana4two]

Thank you, very good info. Will show to DH

[Ozz]

Here is the info on the repair kit, you will have to turn your computer sideways

[racquetballfreq]

Ozz,

I have almost exactly the same crack as you show in your slideshow. Mine is on the galley tank. I have a couple of questions for you:
1. You mentioned installing (2) rubber clamp couplings to relieve the stress on the tank, but my valve, (that you access from between the tires), is right after the tank connection. How did accomplish this?
2. From your experience with using the "plasti-mend, did you find that it was different then just regular ABS glue?

Thanks

[jcurtis934]

From ordering the kit to repair my galley tank on my 3800, it isn't plain abs glue. And the last time I went to buy abs glue for making my temporary drain hookup, there wasn't any at at home depot...just a new green colored formula. The stuff in the repair kit is black and really softens the tank and builds up in thick layers. I had to drop my tank as I had the top side seam open up from overfilling as well as a split on the bottom. Tank over the axles...good luck with that if it isn't in plain sight and obvious. On the crack in the bottom of my tank...looked like a pin hole until I scuffed up the area with the green 3m pad...then it showed up as over an inch wide as water tried to seep out. Repair in place would mean drilling a small hole to allow all the tank water to drain out...then cover with the fiberglass window screen mesh that is laid into a bit of the black repair chemical, then immediately covered with more of the chemical to form a single wet layer. After a bit of time, this is followed up with additional layers of chemical only. Since I had to drop my tank, I filled it with water from a hose as it sat on the grass behind the rv and could see that my seam separation was at least a foot long...I repaired the seam ALL the way around. Since your tank is over the axles, if you have to remove it...there will be square tubing holding it in place that needs to be taken out as well as cutting the exit pipe free of the rest of the piping after the valve connection AND cutting the inlet pipe in the sink cabinet about 2 inches above the floor where it disappears into the 3 inch thick subfloor. Naturally, all pipes would be cut free first, then supports removed. It is kind of fun to lay on your back under the rv to do all this. Sort of.... john

[Ozz]

quote:Originally posted by racquetballfreq

Ozz,

I have almost exactly the same crack as you show in your slideshow. Mine is on the galley tank. I have a couple of questions for you:
1. You mentioned installing (2) rubber clamp couplings to relieve the stress on the tank, but my valve, (that you access from between the tires), is right after the tank connection. How did accomplish this?
2. From your experience with using the "plasti-mend, did you find that it was different then just regular ABS glue?

Thanks

Flexing might not be a problem concerning leverage of a long drain run for you. John's post explained the repair kit well.

[racquetballfreq]

John,

Thanks, yeah, I just love laying my back and having various chemicals drip down my arms onto my face.

I will definitely give this a try with the tank in place as Ozz's photos show...just take it slow and make sure I catch on of the crack.

[racquetballfreq]

.....Thanks Ozz!

[Ozz]

You bet, good luck with it. When I repair.. or try to repair something, I figure.. it's already broke, so ???

[mazboy]

the best way this time of year in canada is to take it to a dealer and have them fix it.

[jcurtis934]

One isn't going to be doing this in the winter unless it is inside a heated building...per manufacturer...works best 50 to 80 F range. I didn't find that high 90's and high humidity was hard to work chemical in...just tended to get thicker faster as you spread it. As ozz says, it's broke anyway. If you can't fix it, it's still broke and good education. Ozz would probably agree that this stuff is like snot. If you clean the area to be repaired and follow directions, it will work. What you aren't going to do is use the tank soon after completing the repair. And I would advise taping that sink faucet with blue painters tape so that someone doesn't have a brain fart and try to use the sink. In a way, I am happy to have had the chance to pull down part of the under belly to see what was done at the factory. Expect lots of sawdust, dropped screws, hydraulic fitting caps, wires not secured in place, and anything else that is used in the build process. If you find that the tank has to come out, it isn't that big of a deal. Just have to put together some pvc parts to hook up the sink outlet pipe to the pvc drain pipe by using flexible boot fittings on each end. These same boots will be used to reconnect the tank inlet and outlet pipes when the tank goes back in. John