Sewer Knife Valve Aggravation

[astrungis]

Ever have a really hard-to-pull black tank valve? Me too. No matter how much you try to grease the pull, it doesn't help. And then, it doesn't close all the way. Well, I tried to replace the blasted thing and it turned into a project from hell. I ended up re-assembling it and leave it the way it was! The issue is that the plumbing manufacturers at the plant assemble the sewer pipes in place leaving no room or tolerance for switching out pieces. I have no idea how the poor folks at the RV service places do their job - miracle workers! My intention was to put in an electric knife valve to avoid the manual pull. Just to get out the darn old piece was an effort in itself. Then to spread apart both 3" sewer pipes to fit the new one back in was impossible. There is no give! Uhgggg

[poloace]

I feel your pain. I have had 1 cable break, and one valve go bad.
I like the old manual valves that were located were they can be reached and replaced easily.

[rohrmann]

When we had a black tank valve fail a couple years ago, CW near Boise replaced all the broken parts, the valve and both flanges, and in doing so, they installed a common flexible rubber coupling between the elbow at the valve and the wye fitting downstream. I almost think that this could be a preventive thing to do to a new rig to allow a bit of movement to prevent plumbing and possibly tank damage.

[jcurtis934]

Bob has the proper answer. Just like a house, when any work needs to be done, it is cut and add flexible boots or replace everything downstream of what you are working on. John

[astrungis]

I never thought about that but will keep it in mind for the NEXT time!

[cw3jason]

I had to do this on my previous trailer. there was debris in the grey tank valve preventing it from closing all the way. getting it back in was very frustrating. I did find using a putty knife and or dry wall trowel helped keep the seals in place and allowed me to slide the valve back into position. I hope this trick helps someone save some time in the future.