PDA

View Full Version : Black tank not draining fully



Rockin
05-24-2004, 12:08
If have drained my black tank three times now and never get it completely empty. I finally figured out to shut off the pump and open the toilet and shine a flashlight in. I should get at stick and dip it in to see how much is left but it is clearly not empty because I am seeing greyish water with small TP bits floating around and it seems quite liquid from the way flush water drips in it.

The trailer is new so I could pester the dealer but it gets really old hooking up to haul it to him and have him not be helpful.

Seems like I could go to the dump station, prop the far side of the trailer higher, drain and run the toilet until it is pretty much clear water in the tank. Then I can look for a restriction in the drain line...

This is a Charmac living quarters horse trailer. the black tank is width wise, about 2' wide and its length is about the same as the trailer. The drain end has a straight shot of ~4" pipe to the valve and that is it. It is a completely separate valve for gray and black water.


Any thoughts?

MTTwister
05-24-2004, 13:15
Rockin - Bandaid's -
1. Run the far side up on a "speedy-ramp" ( one of those Aluminum ramps for changing a trailer tire).
2. Re-plumb the gray water so a second drain option would be to flush the black water tank with the grey water ( major re-do on a new trailer.)
3. - You need some liquid in the black tank anyways - to dissolve the 'de-stinkum' you put in the holding tank at the start of a trip ( ie live with it?)

Always chaps my giblets when a guy has to redesign and improve on factory delivered products. If that tank runs the full width of the trailer, that's a pretty big tank - would need a good slope to the bottom to get it all to drain out seems to me.

Not the funnest job of getting home off a road trip, either. Would rather clean out the horse poop than drain my old travel trailer, have the valve not full close, get goobers all over the gloves, forget and pull one glove off by biting the finger tip and .... you get the picture.

Like I said, no help, and I bet the dealer isn't gonna help in re-designing the factory delivered tank set-up. Oh, new trailer = warranty issues on any mods. Hmmm - maybe the ramp.

tanker
05-24-2004, 17:36
A few suggestions. Always put about 3-4 gallons of water and pour in some chemical before your trip. Always flush using lots of water to help break up the solids. Sounds like you might have a clog at the outlet. Did someone use too much paper? The wrong kind of paper? You can buy tissue digester, and a chemical available at most RV centers, Campgrounds, and also at Walmart. There is also a wand you can buy or make, with a hose connector and ball valve on one end, and the other end is capped off, with a 1/4" hole drilled on one side. Use this to flush out the tank, from inside the toilet. You can also buy a remote flush kit. You drill a hole in the holding tank, so it will spray water directly into the outlet on the other side, this works well.
For now, I would add some chemical and the digester, and lots of water, about half full. Now add a bucket of ice cubes through the toilet, and drive it around for a few miles on a road to slosh everything around, then go to a dumpstation and dump. Most RV's are made with a slope towards the outlet dump valve.
Becareful opening both grey and black valves at the same time, you don't want any black in the grey tank.
Most problems occur when not enough water is used in the black tank. smile.gif

Tough Guy
05-24-2004, 17:41
It is also possible your vent is not working correctly, will it drain completely with the toilet flush valve open?? A similar problem happened to a camping buddies new trailer, he was using household toilet paper and plugged up the vent and it would not drain completely.

Cheers

Rockin
05-25-2004, 08:05
It doesn't make a difference if the toilet valve is open. We're using RV toilet paper. The first trip, the kids didn't take us serious when we said not to poo in the trailer and for the girls to not use pee paper. Hopefully it isn't plugged with paper.

As fast as this thing fills, I wonder if 3-4 gallons of water would fill it...

tanker
05-26-2004, 01:07
Rockin, "IT DOES MAKE A DIFFERENCE IF THE VALVE IS OPEN" :eek: Yes it does. Only leave the "GREY" valve open when connected to a FULL hook-up. The "BLACK" tank valve MUST remain CLOSED, until you are ready to empty the BLACK tank. This way the liquid and solids will mix, and flow out easier. If the black tank valve is left open, then only the liquid will flow out, leaving a pile of "P**P like a mountain at the base of the toilet. (been there and done that, many moons ago, using sticks and a coat hanger, not fun :mad: ) Hope this helps your sticky problem. ;)

Mudflap
05-26-2004, 03:50
LEAVE THE BLACK TANK CLOSED UNTIL YOU ARE READY TO DUMP!!! I would suggest filling the black tank about 3/4 full before dumping (with chemical). I would also suggest that you leave the grey tank closed as well. When you dump tanks dump the black water first, close the valve then dump the grey water it will flush the hose out. We have been pulling an RV for twenty years and never had a holding tank problem using this method. Good luck.

Rockin
05-26-2004, 07:52
Oops, didn't make myself clear. Someone suggested opening the TOILET VALVE while dumping to make sure the roof vent wasn't causing the problem. The last dump, I had the toilet valve open with water flowing in.

tanker
05-26-2004, 13:37
Ok on the toilet being open. As mentioned above let the black fill up near 3/4 if you can, then dump. You need more liquid than solids. Driving does mix things nicely. Scott tissue is also one of the best for RV use, as it disolves easy. The Camping facilities sell some high priced tissue, but Scott is right up there. ;)

letsgo
05-26-2004, 19:14
I have used a 3" clear plastic back flush adapter that attaches to the sewer hose from camping world for the last 2 years.
In that period I have never had a leaky sewer gate valve, all the sludge and toilet paper,paper towels, all get flushed out before leaving our camp site, also flushing the tank each time its 3/4 full there aren't any odours, grey water has never been a problem.

good luck

saywhat
05-29-2004, 08:41
My 1999 Holiday Rambler Alumascape fifthwheel camper had a blackwater holding tank problem since new,a problem not shared by the previous fifthwheel I had for 10 years.I would add 2 gallons of water and chemical to start out with,but soon would have blockage as to where you could not flush the toilet.Upon draining the tank only about 8 gallons would come out(40 gallon tank) but still could not flush toilet.The tank has a flushing hose but that did not help either.My camper usually is parked at one location for several weeks and tank only dumped when near full.Finally found out that the inlet from the toilet was located at the high end of tank with the tank drain located down slope at other end of tank.The solids would just pile up below the toilet inlet blocking off that end of tank to the extent that the vent pipe would plug up too.Got the tank cleaned out and did some measuring and found that it took 11 gallons of water added to tank when empty just to get the water level so there is water below the toilet inlet.Have been adding the 11 gallons and no problems.Could hardly believe that H-R could build something like that.The old Prowler only took a gallon and drained soo well.Sorry for the long post but do not count anything out.

Web
05-30-2004, 13:07
At one time I was having problems with my black tank drain.. After several experiments, my solution was to take a garden hose and stick down the toilet into the tank, with the water going full pressure. I kept twisting the hose so as to direct the water pressure all over the place inside the tank. When the tank was getting full I'd shut off the water and open and close the drain a bunch of times. All the stirring and the weight of a full tank, eventually caused all the blockages to let go. It probably took 4-5 procedures till the last big lump came out and then it was just clear water.

Hope this helps

GARY PAGE
06-29-2004, 19:04
Well I have a soultion if you live in the country like I do. The traps loose the water as you tow and the stink rises. When I get home I flush the takk with water 3 times and then install the green stuff and fill with a few gallons of water. Then even if the traps loose water in tow to the site is doesn't stink, Works for me. If you live in town they would have you aressted for flushing the tank in the yard!!!