Hose Clamps On Holding Tank Drain?

[tireman9]

My dump lines were improperly installed by Coachmen when they assembled the RV. They decided to angle the shut-off valves down which makes the effort to open or close the valves higher than necessary. This placement also has resulted in the valve from the black tank being broken by road debris being thrown at the plastic valve by the rear tires.

Since I have to now do my second valve replacement, I want to try and re-locate the valve in a more horizontal position to make actuating easier and also to move the valve up away from the trajectory of road debris.

What I need to know and confirm before I complete the disassembley is what the hose clamps are clamping?

Is there a piece of large rubber hose that I can replace with new and relocate the hard ABS lines? The area near the clamp feels hard as if it is actually plastic and not rubber. If it was a piece of hose I would think it would need to be clamped around the tank exit and another clamp around the ABS pipe but there is only one clamp.

This shows the bad location of dump valves

You can see the mud flap I added in an attempt to protect the valve but it wasn't enough. You can see the broken handle but not the cracked valve body.

Here is the Black Tank Clamp.

I have started the valve removal

Here is Gray tank clamp

[BillAdams]

The input and output pipes that connect to the valve are not securely connected to anything. Just empty the tanks and then loosen the 4 screws that hold the drain valve in place and you will be able to rotate the drain handle 360 degrees barring the obvious obstructions. You should not have to touch anything else unless you need to full remove the valve to relocate it to a more desirable angle. Even then you will not be touching the hose clamp or anything else if I am seeing the pictures correctly and understand your end objective.

[desertdeals69]

You should have asked me at Redmond!! Just as BA said just loosen the four bolts and rotate the valve assy to the desired angle and tighten the bolts.

[huffypuff]

This should help you. http://rvtipoftheday.com/rv-repair/how-to-replace-an-rv-waste-dump-valve

[manholt]

Thank you, Ray.

My black valve has been getting harder to pull, so now I will replace it....I hope!

[wolfe10]

Replace, and/or grease with silicone grease (the clear stuff in the plumbing section at Home Depot, etc). It will keep them in good shape for more than a year.

[tireman9]

As cold weather hits Ohio the job of re-plumbing the dump valves and fixing the screw-ups in the lines as installed by Coachmen is going slower than hoped. But I am making progress. Have new replacement valves, new ABS pipe and appropriate rubber hose connectors. Am removing the old solvent joint on the black tank which is a slow job but Coachmen knew they would not have to cover the cost of repair under warranty so I understand why they did the half-a$$ job. They probably saved at least $1.50. Oh well that's the real quality seen from our RV assemblers.

I note in Nov FMCA mag on pg 22 "House Calls" a picture that looks similar to my tank exits. I see the hose clamp around the ABS pipe.

What purpose does a hose clamp serve on solid ABS pipe?

[hermanmullins]

Roger,

They put it there so folks would ask, "why a Clamp on ABS Pipe."

Now a word of caution even though you have drained the Holding Tank be sure and raise the coach so the outlet is up about level. You surely don't want any surprises.

Herman

[wolfe10]

Correct.

Anytime you are working on a gray/black tank, tilt the coach (levelers/2x6"/ etc) TOWARD the drain to drain, then the opposite way before working on the system.

Will save you a "bad bath".

[desertdeals69]

Herman and Brett, you are absolutely correct.

I had a customer come into my shop and told me that the tanks were empty and my tech found out the hard way they were not!

[tireman9]

Tanks are empty & flushed. so no surprises for me.

Gary Bunzer said "you’ll see that clamp (and sealant) whenever the holding tank is made out of HDPE; high-density polyethylene. You cannot cement, bond or weld dissimilar thermoplastics. The outlet of a PE tank is tapered a little and some factories could not understand that the tighter you tightened the clamp, the more it tried to squeeze the ABS pipe out of the hole. It was necessary to cut the ABS outlet pipe to just the right length so that it wouldn’t slip out and yet would not protrude too far into the outlet, trapping debris under the outer circumference of the pipe. It wasn’t necessarily a great design but when coupled in tandem to the other tank outlet via the whole termination assembly, it sufficed. Today you’ll mostly see spun-on or welded fittings to make the connection. "

I do see what appears to be a separate piece of pipe inside the neck of the tank. Apparently the tank is not ABS, (else why the clamp and inner pipe?) even though Coachmen tried to solvent glue an ABS pipe union onto the neck of the tank. They did not try and attach the inner tube to the ABS pipe or fittings. That may be why they also applied some type of sealant on the outside of the tank neck to pipe union joint. Really abysmal design, engineering and workmanship in my opinion.