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Sunday, September 5, 2010

Holding Tank Cable Pull Failure

I own an older Holiday Rambler motorhome and my black holding tank cable broke at the valve. The one I pull to dump the toilet holding tank. How do I repair this?
Larry, (Dayton, OH)

Larry, my alternate repair fix for those dreaded broken cable pull termination valves is to install a Drain Master electric holding tank gate valve and forego any propensity for repairing the mechanical cable or rod. Some old-school designs are simply best left to obscurity! Check out this website:

You’ll have to gain access to the existing valve anyway. And since you’re going to that extent, simply install the electric valve and forget about cables. Just push a button! Just remove the existing valve (sandwiched between two adapters at the tank outlet) and install the new electric valve. Make sure the valve body is oriented vertically; the more vertical, the better, even if it’s only slightly upwards. In fact, EVERY termination valve should be mounted in this manner to avoid waste and crud from entering the body cavity of the valve. This will eliminate the possibility of the residue drying out and putting a bind on the sliding gate portion. This is typically why termination valves fail in the first place. RV manufacturers simply should not mount termination valves horizontally or angled downwards, yet it is a very common occurrence. 

Next, route the wiring harness to a convenient location inside the plumbing bay or compartment. In fact it’s easily accomplished by most RV handypersons….if the cable broke while the valve was in the fully opened position, that is! If the holding tank is full, however, it presents a greater challenge. Perhaps the tank can be pumped out through the toilet by a local septic company, but this is difficult at best. Holding tanks can implode through the efforts of an unknowing honey bucket operator! Perhaps a local RV service shop can do the installation for you. 

Removing the broken valve can be a messy proposition if the tank contains waste. Some RV facilities have a dumping area that employs a huge funnel device whereby the valve can be removed and the contents allowed to flow into the funnel and into the sewer inlet. Pro RV shops will have their methods, but the important thing is getting the old valve off, flushing out the tank completely and installing the new Drain Master. By the way, for the optimum set-up, replace the gray tank valve at the same time.


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