Forum Discussion

mabynack's avatar
mabynack
Explorer II
Dec 15, 2015

Gray water tank leak

My FW has been sitting for over a year, so I decided to take it out for a shakedown and see what needs to be repaired. I made it through the whole week and when I started packing to go home the gray water tank sprung a pretty good leak. It was a big let down. The underside of the unit is sealed, so I can't see exactly where the leak is. If it's like everything else, it will be expensive.
  • I called the repair facility and they confirmed that the Gray water tank had split. The new tank is around 200 and another 400 for installation. The new awning fabric is 600 with labor.
  • mabynack wrote:
    TomHaycraft wrote:
    Earlier this Fall my front gray started leaking. Without the time or place to do the work myself, it went to the shop. Crack was 2/3s the way up one of the corners. After removal of the underbelly and during the leak test, they could see the cracks grow in size, the more full the tank got. In the end? $1,600 and I was camping again ... until a tire blew and now back in shop for repairs and major overhaul of suspension and addition of 3" subframe.


    I suspect that's my problem, too. The fuller the tank got, the worse the leak. The last day I did a load of dishes and washed all the pots and pans. It wasn't until after that the leak got really bad. There's an overflow for the gray water one the outside of the RV. It never had any water coming out.

    I need to get a new awning and a couple of the plumbing vent caps need to be replaced. It may be an expensive trip.


    Don't think just because the leak gets worse when full its an issue with vent or a crack located up high.

    Mine was leaking the same way, the higher the level the more it leaked, when I made a cut in the underbelly to see what was going on I found the leak at the union of the tank and 3" drain on the bottom. When I looked at the crack I could not even see it when empty but as I put more water in the tank the crack got larger and it started to leak.

    Ron W.
  • If it is the gray tank, there are plastic welders that can possibly fix it cheaper than buying a new tank.

    You will need to remove the under belly and pull out all the insulation and replace with new dry insulation, after leak is fixed.
  • mabynack wrote:
    My FW has been sitting for over a year, so I decided to take it out for a shakedown and see what needs to be repaired. I made it through the whole week and when I started packing to go home the gray water tank sprung a pretty good leak. It was a big let down. The underside of the unit is sealed, so I can't see exactly where the leak is. If it's like everything else, it will be expensive.

    No telling what is leaking. You have to take off the underbelly to make sure ( a lot of screws). If the leak is only a fitting you are lucky.
    Our sad problem . . . . we were pulling the 5th wheel when we heard a scraping sound. We had a leak from the outside shower, and it flooded the underside. The underbelly gave way, and the insulation was dragging on the road. Long story short. . . . the water soaked and ruined the insulation, and rotted the passway floor. A RV guy came to our site and fixed everything . . . . . $3000 worth. The insurance company paid for the repair. I hate water . . . If you ever see a sign of a water leak, fix it now.
    ken
  • TomHaycraft wrote:
    Earlier this Fall my front gray started leaking. Without the time or place to do the work myself, it went to the shop. Crack was 2/3s the way up one of the corners. After removal of the underbelly and during the leak test, they could see the cracks grow in size, the more full the tank got. In the end? $1,600 and I was camping again ... until a tire blew and now back in shop for repairs and major overhaul of suspension and addition of 3" subframe.


    I suspect that's my problem, too. The fuller the tank got, the worse the leak. The last day I did a load of dishes and washed all the pots and pans. It wasn't until after that the leak got really bad. There's an overflow for the gray water one the outside of the RV. It never had any water coming out.

    I need to get a new awning and a couple of the plumbing vent caps need to be replaced. It may be an expensive trip.
  • Earlier this Fall my front gray started leaking. Without the time or place to do the work myself, it went to the shop. Crack was 2/3s the way up one of the corners. After removal of the underbelly and during the leak test, they could see the cracks grow in size, the more full the tank got. In the end? $1,600 and I was camping again ... until a tire blew and now back in shop for repairs and major overhaul of suspension and addition of 3" subframe.
  • Mine started to leak also awhile back. I took a chance and cut a three sided box cutout in the Coroplast where I thought the 3" drain exits the tank and sure enough that's where the leak was. That exit junction is the most likely spot for a crack because the drain pipe flexes a bit when driving.

    Took some ABS tank repair stuff and fixed myself.

    Some Gorilla tape fixed the Coroplast cutout as good as new.

    Ron W.
  • Why do you think grey tank.........did you overfill it?

    Could be an easy fix...could be a PITA fix but not expensive....could be a big repair/replacement

    W/O opening underbelly it's all speculation.

    Good Luck!
  • Are you sure it's a leaking tank? Dripping down from a sealed underbelly, it could be coming from anywhere...leaking plumbing, etc.

    Good luck with it.