Had a leak somewhere down low on my freshwater tank and I was not looking forward to the whole process of removing and repairing it. But after talking to the dealer about the cost of having them do it I decided to just dive into it myself.
1st I’d like to thank GMFL for his advice.
I discovered that the tanks are installed while the frame is upside down during the build process. What this means is that the only connections you can access prior to dropping the tank are the fill and vent connections at the fill station on the side of the trailer. Once the tank is dropped you have about 4” to get something in to cut the suction line and pressure drain line (both pex piping). The pressure drain line had a screw on fitting but the nut is on the inside of the belly pan. Of course you are doing this with minimal height to work with under the trailer. I wound up jacking the trailer all the way down to get at the bolts on the aft side of the tank, then jacked the trailer all the way up and worked from the front for everything else. Every inch of room you can get really helps when working under the trailer. Once the lines were cut I was able to get the pan and tank to drop and slide it out from under the trailer. Fortunately there was enough slack in the cable for the tank sensor to drag the tank out from under the trailer to see how to disconnect it. I had the catcomm sensor so it is just like unplugging you phone from the wall.
Now that the tank was out I could see that the spin weld fitting for the tank drain had cracked. My options were:
1). Buy a new tank ($220 + $90 shipping)
2). Replace the broken fitting ($1.50 for the fitting + $150 for the bit to spin weld the fitting on)
3). Cut off the fitting flush with the tank, plug the hole, and install a bulkhead fitting ($10)
4). Cut off the fitting flush with the tank and use a heat gun to try and “weld” it back into place
5). Buy polyethylene welding strips to repair the crack.
Unlike GMFL, I tend to take the frugal approach (no offense intended Ronnie) so I started with option 4. Much to my surprise it looked like it was going to work. Much to my chagrin, I noticed another crack on the suction line fitting in the same place as the other cracked fitting. I also realized that my initial “weld” wasn’t very stout because I bumped the fitting and water started seeping out again. So it was on to option 5. I cleaned up and smoothed out the remnants of my initial weld job on the drain line fitting and plugged the hole using poly welding rods with a heat gun. Then I welded the crack on the suction line fitting. I got the hole plugged tight on the 1st try but it took 3 times to get the crack completely sealed.
I decided not to replace drain valve because with the valve open it still left about an 1” of water in the tank so I just modified the belly pan to make access to the bottom plug much easier.
Now that the tank is fixed comes the lovely task of getting everything back in place. Now remember, with the belly pan on you can’t get to any for the connections so I used a small line under either end of the tank that I attached to the axles to hold the tank up and in place so I could connect everything. Once that was done I didn’t want the tank to drop to the ground for fear of cracking the fitting I just repaired. The tricky part was installing the belly pan without allowing the tank to drop. Needless to say I got it done plus now there are a couple of lines in the belly pan and under the tank so that if it ever needs to be dropped again I can do so without having to drop both at the same time.
I finished up late so I held off filling the tank and checking for leaks until tomorrow. FINGERS CROSSED.