Montana 3402 black water valve

[denniskuj]

I have a 2014 Montana 3402RL and am already having trouble with draining the black water tank. Sometimes it will drain completely and sometimes it seems like the valve won't close completely. Do you have to cut the underbelly of the RV to gain access to the black water valve? I can't believe Keystone would not install some type of access panel to work on these valves. Does anyone know how you access the valves without cutting a brand new RV apart?

[Ron]

A couple of times our black tank valve appeared to not want to shut all the way either, it appeared that there were some solids, paper in the way of the knife valve, I just ran the black tank flush a little longer working the valve open and closed and all worked fine afterwards...if the knife valve does not shut all the way when using the black tank all the water will drain out slowly and leave just the solids behind leaving a, well you no what....

[therink]

I have had the same problem a couple of times with my 13 five. I ended up cutting a hatch into the belly below the gray/black valves. Removed my black valve and found a baby wipe jammed into the valve seat. No amount of flushing would have removed it. This happened twice. Lesson learned, no baby wipes in the potty.
I now have a nice access hatch to service the valves in the future.

[denniskuj]

Thanks, I was hoping Keystone would have put in an access panel, seems like a logical thing to do. Anyway I guess I will be doing the same as you did. Thanks again.

[bobbecky]

Have had to access our black tank valve, and just lowered part of the coroplast from the side and back edges. No matter how you get to it, it is not the easiest thing to work on. Just make sure you have flushed the tank a long time, as it can be a messy experience. Your black tank should be on the curb side of your rig.

[therink]

X 2 on flushing the tank. I flushed mine like 10 times and still got a face full of poo water when I wrestled the valve loose.
On my rig, the black valve and front gray valve are centerline wwith the discharge pipe and are Tee'd together. I closed up my belly with a 18"x18" piece of coroplast that I got at a local sign shop. It is easy to remove in the future and is sealed well while in place.

[dmcgrew]

The best thing I ever did was attach a blade valve to the discharge on the trailer. I applied silicone sealant to keep it from coming loose while traveling. Now even if the black or grey water tank valves leak I dont get my shoes washed when I remove the cap from the discharge port.

I still learn if the valves are leaking because after I hook up the drain hose and before I open the trailer drain valves I open the blade valve and can hear if significant water comes out of the drain pipe. This has made draining tanks significantly cleaner for me and the dump station.

[therink]

The problem with modern day rv tanks is that they are very flat. The solids fall to the bottom, and they are the last to move out with the gush of water. I realized that there is also a 1/2 inch or so lip where the bottom of the tank is lower than the 3 inch drain valve flange. All that it takes is a for solid matter to be caught in the valve opening to jam the valve when you close it. In my case (twice) it was a cloth baby wipe stuck in the valve. I have not had a valve issue since I banned baby wipes from being used in the bathroom.

[Fishhawk]

X2 on the blade valves installation!!

I did the same thing and it was an easy and inexpensive solution

Originally Posted by dmcgrew

The best thing I ever did was attach a blade valve to the discharge on the trailer. I applied silicone sealant to keep it from coming loose while traveling. Now even if the black or grey water tank valves leak I dont get my shoes washed when I remove the cap from the discharge port.

I still learn if the valves are leaking because after I hook up the drain hose and before I open the trailer drain valves I open the blade valve and can hear if significant water comes out of the drain pipe. This has made draining tanks significantly cleaner for me and the dump station.