Voltage Dump Valve Replacement

I assume your valves are hidden inside the belly and not visible. I would open it up and look to confirm the sizes. My rig is from a different manufacturer
than yours, but both valves on mine are 3". I recently replaced the pull cables on mine.

I have manual on our ATC. I find using the valve lubricant by Thetford makes a big difference on both valves. Also, no coffee grounds in the grey tank keep it working better as well.

nayther wrote:

Durb wrote:
Interesting in that I have electric dump valves and would prefer manual valves. I belong to a forum where all the trailers have electric valves and some have switched to manual. I hope they have improved their reliability since mine were installed.

Funny, was just thinking how I'd like electric too. The cables were routed poorly on mine (imagine that) and are hard to pull/push, just waiting for the day one fails. Speaking of that need to do some PM on these.

My valves were made by Wastemaster and are now thirteen years old. I spent numerous times laying on my back with a 1/8" hex key to operate them manually (not in the best conditions). I found the rocker switches were weak and kept too much voltage from the valves. I replaced the switches and offered up more voltage from a lithium battery. This, and consistent tank cleaning protocols have them working 100% of the time recently. They are nice when they work.

nayther wrote:

Durb wrote:
Interesting in that I have electric dump valves and would prefer manual valves. I belong to a forum where all the trailers have electric valves and some have switched to manual. I hope they have improved their reliability since mine were installed.

Funny, was just thinking how I'd like electric too. The cables were routed poorly on mine (imagine that) and are hard to pull/push, just waiting for the day one fails. Speaking of that need to do some PM on these.

Mine have become less reliable. I put on a Twist On valve when it was new just in case. It’s paid for itself many times over.

Durb wrote:
Interesting in that I have electric dump valves and would prefer manual valves. I belong to a forum where all the trailers have electric valves and some have switched to manual. I hope they have improved their reliability since mine were installed.

Funny, was just thinking how I'd like electric too. The cables were routed poorly on mine (imagine that) and are hard to pull/push, just waiting for the day one fails. Speaking of that need to do some PM on these.

Interesting in that I have electric dump valves and would prefer manual valves. I belong to a forum where all the trailers have electric valves and some have switched to manual. I hope they have improved their reliability since mine were installed.

rjr6150 wrote:
35 years Colorado Master Plumber. I can assure you the valves are 3” & 1.5”. Sad when individuals don’t know the correct answer they just throw something out there.

Ditto. LOL

Also worth noting, The valve sizes are an RV industry standard, they aren't specific to a Voltage, or different sizes on various other RV.

Well, I got under the trailer, removed the covering and located the 2 main dump valves. The 2 valves are the same size, that being 3" and about 18" apart. both dumping into the main 3" pipe. I also have a 1.5" pipe coming from a rear gray tank that is only used for the kitchen sink and that valve is working. RV tech will be replacing the current 3" valves with electrically operated 3" valves next week.

35 years Colorado Master Plumber. I can assure you the valves are 3” & 1.5”. Sad when individuals don’t know the correct answer they just throw something out there.

Try to buy 2" and 4".