frisco_dave wrote:
Trailer is a KZ Coyote, 10 years old. I think over time, the bumpy roads have just done it in. The last trip we took, while the highway was paved, there were a lot of dips in the road, which I suspect pushed it over the edge.
Hi,
This may help.
The 10 years old does ring a bell for cracks, but there are reasons they crack. And the reason should be addressed along with the crack repair.
I'm not sure if you are the original owner of the camper or just bought it a few years ago. I have seen and repaired 3 campers for friends with similar cracks. While the piping setup is not identical to all 3 of them, they all had the same problem.
Look at your setup for this and see if this makes sense to your camper. The one pic of the crack does not show the whole setup of the tank mounting and the piping to the dump valves.
How is the 1 1/2" pipe run from the grey tank to the dump valve routed?
Your crack is on the bottom of the pipe. That points to the highest stress ends up concentrating on the bottom of the weakest joint. Right where it cracked. The tank and piping had to have stress at the bottom for it to crack there.
Do you ever tow with water filled in the tank at highway speeds? Naturally you drive in camp with full tanks to the dump station, but that is slow, not doing 50 - 55mph or faster on the highway/back roads over bumps.
What I found on the 3 I corrected, was age of the camper was in the 10 to 15 year mark. The pipe routing was very rigid between the exit of the tank to the dump valve. Often there was one or two elbows in the 1 1/2" drain piping and the 1 1/2" pipe was rigidly mounted. The actual grey tank hung from the bottom of the camper. The bottom of the tank had no supports under it as they hung from flanges on the top of the tank off the bottom of the camper.
As the tank fills, the bottom of the tank bellows outward and downward. That bellowing moves the outlet fitting of the tank in relation to the dump piping. There is no flex in the piping as it was mounted rigid. Something has to give and the weakest joint gets the stress. Over time that stress creates a crack and more movement just keeps ripping the pipe apart. If you tow at highway speeds with water in the tank, the issue is very aggravated and can happen quicker. Even in the campground, a full tank is breathing and the tank is bellowing. There is stress on the piping from the bellowing.
How I fixed all 3 of the campers. The crack was ground deep to allow for a ABS solvent weld repair for close to full pipe wall thickness with fiberglass screen mesh in-between 3 layers. 24 hour cure time between each layer. This repaired the cracks as the weak point was the joint to the tank, not out from the tank like yours.
Then, I cut the discharge pipe in 2 places, removed 1/8" of the saw joint at each cut and put 2, 1 1/2" Fernco coupling fittings in the discharge line. Each camper was slightly different routing to the dump valves, but the need was to allow the 1 1/2" pipe to flex in 2 directions when the tank stress would build. The rigid pipe hangers where changed to be pipe strap that would create a positive down stop, but yet allow the pipe to breath and flex at the 2 Ferncos.
In your case, creating the rubber joint at the crack is good if you can get the Fernco to seal and have the right sizes. If this will not work, then repair the crack as I noted above and install Fernco's down stream of the repair to get the stress off that location. Even if you have 1 Fernco at the crack joint, look to add a second down stream to allow the pipe to flex more when the tank bottom bellows out. To see the bellowing, look at the tank bottom empty. Then fill it full and look again. You will see it, the tank outlet fitting is moving during this bellowing.
I have pictures of all this if interested, just ask.
Hope this helps.
John
2005 Ford F350 Super Duty, 4x4; 6.8L V10 with 4.10 RA, 21,000 GCWR, 11,000 GVWR, upgraded 2 1/2" Towbeast Receiver. Hitched with a 1,700# Reese HP WD, HP Dual Cam to a 2004 Sunline Solaris T310R travel trailer.
