Replace/repair grey holding tank

[fonsecaangelm]

Hi there! We have a leak in our grey holding tank, and already patched it with ABS, but either it didn't work, or we didn't find/patch all the cracks. So....we will be opening the bottom back up and checking again, but, we are thinking we might want to replace it.

Does anyone have any tips on
1) where to find the replacement part # (is there a registry of part numbers for our year/model?)
2) once I find the part, has anyone found an owner's schematic of how components are mounted?
3) what to watch our for? who's done this???

Thanks for any information

 

[WeBeFulltime-MOC]

Would be very helpful to know the year and model of your Monty. Many members add a signature with the information included.

 

[fonsecaangelm]

thank you! I just added our signature, but just in case!! 2005 Montana 3400RL.

yes! We bought it last summer, and in the fall discovered that the underbody vinyl (?) was dripping water. so we opened that up and discovered that the grey water tank was leaking. We found it was cracked under the drain hole... so for several weeks and searched videos/etc on how to fix it. We tried multiple things, but we THOUGHT the one that held was the black ABS cement. so after watching it for a while with no leaking we buttoned the underbody back up.

Lo and behold....3 weeks later, it was leaking again. I suspect there was another crack we didn't originally patch (but could be wrong, we will be opening it back up next week...hubby had knee surgery and has trouble climbing under there). If we find a crack higher up (we think it is, which is why it started leaking after getting fuller?) then we are thinking stop messing with it and just put a new one in. Of course ordering the correct part is as big a hassle as removing the tank!

any help is appreciated.
amf

 

[shovelhead86]

Go online and find a product named Plasti-mend. It works. After repairing support everything better.

 

[jcurtis934]

Okay, have done my black tank as well as my galley grey. The repair should have been done with plastimend and with the tank out. The failure mode on my galley tank was on one of the ribs on the bottom that got worse with more grey water in it as these tanks expand quite a bit with stuff in them. I also had a major leak at the top lip where the tank top is bonded to the lower molded part of the tank. Haven't had any issues since repair. Black tank failure was my fault, leak around top seam. Tanks are only held in place by two rails under the side seams at the top. One of the rails is removeable. Remove wiring to tank, make sure as much liquid I'd out of tank, cut inlet on top of tank leaving enough pipe for a rubber no hub coupling to put back together, cut tank output from rest of output plumbing...again leaving enough room for a rubber coupling to put back together, remove the removeable metal tube under one side of the tank, and lower it out. With tank totally empty and no or little liquid in tank one can use plastimend kit to repair the issue. Tanks have a raised molded in number on them that tells size and pipes configuration of any tank. New tanks don't come with any fittings as far as I am aware of.

 

[fonsecaangelm]

We had everything winterized last year and want to resolve this before using again this year. Hopefully it's as dry as it's going to get....been 7 months! BUT....if we are removing the tank anyway...why not replace with a new one? (other than cost, obviously. Just seems that the time will be worth it if we don't patch it correctly, don't want to work on it all summer).

thoughts? Know where to find part #s and order?
thanks in advance!!!

 

[bobbecky]

We had a grey tank leak a couple years ago which was located in one of the ribs on the bottom. I used a Plastimend kit that has the piece of screen material. Once the repair was complete, I installed extra braces across the frame and used blocking to support both the black and grey tanks. Once the blocks were in place, I removed the braces and reinstalled the coroplast and then reinstalled the braces. I haven't done the galley tank, but we don't let it get that full before draining.

 

[Wheelhouse]

Okay, have done my black tank as well as my galley grey. The repair should have been done with plastimend and with the tank out. The failure mode on my galley tank was on one of the ribs on the bottom that got worse with more grey water in it as these tanks expand quite a bit with stuff in them. I also had a major leak at the top lip where the tank top is bonded to the lower molded part of the tank. Haven't had any issues since repair. Black tank failure was my fault, leak around top seam. Tanks are only held in place by two rails under the side seams at the top. One of the rails is removeable. Remove wiring to tank, make sure as much liquid I'd out of tank, cut inlet on top of tank leaving enough pipe for a rubber no hub coupling to put back together, cut tank output from rest of output plumbing...again leaving enough room for a rubber coupling to put back together, remove the removeable metal tube under one side of the tank, and lower it out. With tank totally empty and no or little liquid in tank one can use plastimend kit to repair the issue. Tanks have a raised molded in number on them that tells size and pipes configuration of any tank. New tanks don't come with any fittings as far as I am aware of.

I have tried the Plasti-mend and abs- cement and finally said put in a new tank. I just blew the black water so figured replace both.
The plastic-mend crack just continued after mending.

 

[jcurtis934]

Who knows why your repair didn't work. Moisture in the tank really hurts the process, which is why my tanks were taken out and stood on end to drain out, then sit in the Florida sun to evaporate stuff inside. I used sandpaper to rough up my bottom split, then allied a layer of the plastimend and embedded the fiberglass screening into it, then followed that up with two more layers of plastimend. Still holding. On the top seam, I sandpaper ed the outside of the lips, forced plastimend into the seam, followed by the above sequence all the way around and things are still holding nicely. Guess you had the bad luck day on yours. Oh well, new tanks to give you long service hopefully.

 

[DQDick]

Replacement tanks can be found at Trekwood.com

 

[Rondo]

Whether you patch the tank or replace it put some support under them. I've heard of metal strapping with foam or rubber between the strapping and the tank or do like rohrmann did and put wooden supports under the tanks. They will hold approximately 40 gallons plus of water and that equals about 340 lbs. of weight pushing down on the bottom or sides of that tank, so some extra support is needed.

 

[richfaa]

With the extended warranty it is a phone call and about 500.00 to replace the tank at a dealer 50.00 of which is on us.

 

[bigred715]

That is where a extended warranty is worth the price when you don't have a place for the do-it-yourself person. Our galley tank leaked and our dealer replaced the tank under warranty. All we had to pay was the shipping of the tank. He also added more support under tank and added venting from the tank all under the replacement cost.

 

[mlh]

If I had to remove the tank I would replace it and add much more support to it. Leaking tanks are a fairly common problem.
Lynwood