Community Forums

jkmcbride54 · 05-18-2018, 10:01 PM

I can't get my gray water tank to empty and my black water valve is leaking. The only valve that is working properly is the one in the galley. I was wondering if this job should be accomplished by a RV repair shop or something that an owner can do without much trouble?
Since it would require dropping the sealed undercarriage should I replace all three valves or just the two bad ones?
Any thoughts or advise would be greatly appreciated.

Bob_C · 05-18-2018, 10:07 PM

A lot of techs would just cut a 3 sided door, with the 'hinge' facing forward to access the valves, then tape the coroplast back up

McRod · 05-19-2018, 03:19 AM

Its an easy DIY fix. But stinky.

Once you get under there you may notice your cable pulled out of its retainer, which prevent you from opening the valve.

If you replace the valve, its 4 screws that hold it in place. Should take about an hour to complete..

Im sure someone has made a Youtube video on it.

txcpl · 05-19-2018, 05:42 AM

I had to replace a black water tank valve last year on our 5'er. To start, I used the leveling system to tilt the RV to get as much out of the tanks and lines as possible. Then I tilted the RV using the leveling system the opposite way to keep any remaining liquid inside the tanks. I dropped the coroplast, along with some insulation, and set them aside. There was not enough room to use a regular saw, so I used a cable pvc saw to cut the ABS plastic pipe. Next I removed the 4 screws to remove the valve. Using this method, I left one connecting end of the offending valve on the ABS pipe and simply installed the new valve. I also used a file to de-burr the ABS where I cut it with the cable saw. I installed a rubber boot to connect the ABS pipe where I had sawn it apart. Next I replaced the insulation and coroplast. However, it was windy that day and I had to have help holding the insulation and coroplast in place while reinstalling it. I also used a couple of 1x2x8 pieces of wood to help hold the insulation in place.

I only encountered 3 drops of "stuff" while performing this task.

Be sure you have the correct waste water valve on hand before you begin this project. Contact your manufacturer prior to starting this project if you have any questions about the correct valve. I had to order a specific one for my RV. The rubber boot is available in the plumbing section of any hardware or big box store. The only time a 2nd person is helpful is the replacing of the insulation and coroplast.

Its not a hard job at all. I did mine in a morning. Get your materials and tools set out, turn on some tunes, and get to work.

Good luck.

bddadles · 05-19-2018, 06:51 AM

It is not hard to drop the belly pan. It just screws in place. If you can manage to only drop 3 sides it will be easier to put back up. It is not heavy. Plus that gives you much more room to work than cutting a hole.
I also don't understand why txcpl had to cut a pipe. As I remember the valves are only held in place by 4 bolts and the valve drops out. Put in the new one and rebolt.

I do agree that you want to drain the tanks first. If you have levelers that will help.

wingnut60 · 05-19-2018, 10:01 AM

If you have ever had to replace a drain valve that had to be realigned perfectly to get the sides to match up to the valve, then removing the valve to fix/replace is much easier for most locations where the valve is. Use of the rubber boot (should be listed as one of the greatest plumbing inventions ever!) to re-align the parts makes it simple.
While your valve(s) may be easily reachable, most are buried in the basement or underneath with all sorts of wires/ducts/piping in the way--that is how mine are. Will have to remember this method when next I have to fix the black tank valve...