My Grey Water Tank will not drain but trickle out and does not seem to empty

[Mainiac]

27 minutes ago, ScubaRx said:

You might try this if you suspect (or know) the vent pipe is blocked by dirt daubers. Make sure the back flow preventer valve is open. Remove the outside vent cover and stick a hose down it. Flush with a copious amount of water.

Three things: make sure the gray (and/or black) line is open to a drain. 

                        Have someone inside to make sure nothing is plugged and back filling.

                        If you hear a "whooshing" sound coming up the vent pipe, shut off the water quickly.

[Overland]

I think if you have a composting toilet, that trick won't work.  The vent for the toilet connects into the vent stack with a flexible tube, in a spot that would almost certainly get water into it if you were to back flush the vent.   So either the tube would get forced off by the water and you'd have to get into the vanity to reconnect it, or it could just send water into the toilet fan and kill it.  

[bhncb]

And if you don't have the composting toilet, be sure to keep an eye on the black tank level. Because of how the vent is plumbed, a significant percentage of water from the garden hose will end up in there. If it is daubers, hopefully the bulk of the nest will be accessible for hand removal out the top and not have to be flushed down into the drain system.

Edited October 2, 2020 by bhncb

[bhncb]

10 hours ago, SeaDawg said:

Here in Florida, plumbers often call them by a brand name, Studor valve.

 

Studor: Original and  gold standard of AAVs.

[Ray and Susan Huff]

14 hours ago, Mainiac said:

They do have scopes designed for a septic tank 'colonoscopy'. Some home inspectors have them, as well as folks that pump septic tanks. It would be a quick look as no more than 40', less if the flex pipe is removed (recommended). If all else fails it would be  an easy thing. A flashlight and mirror might do as well.

Where is access to the inside of the grey tank?

[Imelda]

Hi all. Continuing the topic of the slow draining grey water waste. It does seem that all the valves are working correctly so I tried the suggestion of tilting the trailer to the back so that it might drain better.  So I parked it on a 30% slope and that did the trick of complete and fast draining of the grey water. So now I know at the dump station I am going to have to raise the front of the trailer and maybe that passenger side a little too.  I may have to unhook the hitch from the truck to get it raised higher and may take more time at the dump station.  I may not be the most popular person at a busy dump station. 😀 Anyone have experience on high I should raise the front of the trailer and maybe what angle the trailer should slope from front to back?  I guess the bigger the slope the faster it will drain. 

 

Thanks all for the suggestions. This is really a very useful forum. 

[mossemi]

I admit that it’s nice to find the dump station empty and no one waiting, so don’t rush the process and make a mistake if someone is waiting behind you.  They'll get their turn.  And remember, if I am in your way while driving down the road causing you to flash your lights or beep your horn, I think to myself, if you had just left 5 minutes earlier, we wouldn’t have even met.

I do find it quite common that the driveway to the dump stations often slopes in the wrong direction and the front of the trailer is lower than the rear.  I sometimes raise the front of the trailer with the front jack while still attached.  And on occasion, I have used leveling ramps to raise the rear of the tow vehicle.

 

Mossey

[mossemi]

And speaking of scopes, I have used this for my drain pipes at home as well as inspections in the Ollie while searching for wiring pathways.  The only issue is the 23 feet length is sometimes a hassle dealing with.

Mossey

[Mainiac]

1 hour ago, Susan Huff said:

Where is access to the inside of the grey tank?

Through the discharge at the bumper, ie: the 25'. Also, depending on build maybe loosening a couple of clamps?

[Mike and Carol]

6 hours ago, Imelda said:

I may not be the most popular person at a busy dump station. 😀 Anyone have experience on high I should raise the front of the trailer and maybe what angle the trailer should slope from front to back?  I guess the bigger the slope the faster it will drain. 

Thanks all for the suggestions. This is really a very useful forum. 

Dump station etiquette generally says that you shouldn’t take any more time than necessary.  If I am using a dump station I ensure everything I need is accessible as soon as I get there.  If the dump station isn’t level I try to pull in so the front is high, not always possible.  If I need to, I put a tall block under the front jack and lift the front of the trailer and usually the back of the truck.  I have also had to unhitch and raise.  No big deal, if you socialize a little with your fellow campers in line nobody gets too excited about it.  I’ve even had offers of help.  I’ve noticed that RV’ers in general aren’t in too much of a hurry!

As far as how high to raise the front, I use the bubble level on the jack (which I adjust frequently after leveling with a level),  moving the bubble well out of the bullseye.  Mike

[John E Davies]

Well, IMHO you should find the actual problem and correct it, mine drains in a few minutes. The initial flow is a geyser. I would physically remove the grey valve and look it over intimately, there may be a blockage, like a big glob of hair. With it out you can check the tank itself. The grey tank vent operates through the bathroom when the travel valve is opened (there are three places air can enter: the main waste roof vent, the sink drain and the floor drain. If it is closed, the ONLY way air can enter is through the galley sink drain. If that is blocked by the metal strainer, and the travel valve is also closed, no air can get in the tank at all. Burp burp burp.....

Good luck.

John Davies

Spokane WA

Edited October 3, 2020 by John E Davies

[GraniteStaters]

We are relative newbies, only 80 nights the first year due to COVID-19, but one of the first things we do after setup as is scope out the dump stations.  We have airlift to increase the angle, but we still like to consider how we approach the dump station too as we like to take advantage of the natural incline.  We have only camped at campgrounds that have no waiting at the dump stations so we haven’t felt too much peer pressure, but it is good to know what others expectations are so as not to offend.  

[Ray and Susan Huff]

Sounds like a good practice, if dump station doesn't have an incline, is to drive the curb side tires of the trailer up on a leveling block and, if possible, raise the tongue.  This should cant the trailer to the rear street side corner and make draining quicker. 

Being aware of the trailer's tilt is something we will need to become aware of; our camper van had a macerator sewage pump so gravity was not necessary to drain the tanks.

[bhncb]

38 minutes ago, Susan Huff said:

This should cant the trailer to the rear street side corner and make draining quicker. 

Before raising the curb side, first drain the black tank because it benefits from being tilted in the opposite direction or street-side high.

[Mike and Carol]

8 hours ago, bhncb said:

Before raising the curb side, first drain the black tank because it benefits from being tilted in the opposite direction or street-side high.

I agree with this.  At a dump station just be aware of front to back, with the front higher.  If there aren’t folks waiting then you can fiddle with left to right, but I’ve found everything will drain fine if the front is a little higher than the back.  Mike

[bhncb]

26 minutes ago, Mike and Carol said:

everything will drain fine if the front is a little higher than the back

Yep. I never do any side to side fiddling as long as the site is reasonable. Many are pitched slightly toward the drain which works in your favor. Just scope the dump station out ahead of time and determine the side and direction that going to work best.

[Ray and Susan Huff]

On 10/9/2020 at 4:07 PM, Mike and Carol said:

I agree with this.  At a dump station just be aware of front to back, with the front higher.  If there aren’t folks waiting then you can fiddle with left to right, but I’ve found everything will drain fine if the front is a little higher than the back.  Mike

Would it help to have someone sit on the bed above the sewer drain?

[Mike and Carol]

1 minute ago, Susan Huff said:

Would it help to have someone sit on the bed above the sewer drain?

I don’t really think so, especially if I’ve raised the front with the front jack.  You’d need to be pretty big to change the attitude of the trailer.

Our dump routine is Carol is inside, I’m outside.  She is monitoring the black tank level as I am filling it with a hose connected to the black tank flush.  When we hit 80% to 85% she tells me and I open the valve.  We do this a couple of times, unless we are at a dump station and we don’t want to hold things up too long.  When our last black dump is done she shuts the valve under the dinette seat while I open the gray valve.  While the gray tank is draining I unhook the hose from the black flush.

I don’t think we need to over think this.  If the front of the trailer is a little higher than the back everything will be fine.  Mike

[Ray and Susan Huff]

24 minutes ago, Mike and Carol said:

I don’t really think so, especially if I’ve raised the front with the front jack.  You’d need to be pretty big to change the attitude of the trailer.

Our dump routine is Carol is inside, I’m outside.  She is monitoring the black tank level as I am filling it with a hose connected to the black tank flush.  When we hit 80% to 85% she tells me and I open the valve.  We do this a couple of times, unless we are at a dump station and we don’t want to hold things up too long.  When our last black dump is done she shuts the valve under the dinette seat while I open the gray valve.  While the gray tank is draining I unhook the hose from the black flush.

I don’t think we need to over think this.  If the front of the trailer is a little higher than the back everything will be fine.  Mike

What is the valve you are shutting under the dinette?  None of our RVs has had a valve to shut after draining the black tank and before draining the grey.  We just open the black to drain, then open the grey with the black valve open.  Do the tanks on the Oliver drain separately?

Maybe I should look in the University . . . . . there's probably a video, huh?

[Mike and Carol]

55 minutes ago, Susan Huff said:

What is the valve you are shutting under the dinette?  None of our RVs has had a valve to shut after draining the black tank and before draining the grey.  We just open the black to drain, then open the grey with the black valve open.  Do the tanks on the Oliver drain separately?

Maybe I should look in the University . . . . . there's probably a video, huh?

On some Olivers there is a valve under the back dinette seat that opens and closes the black flush line.  For years we used to just keep it open because there is a back flow on that line as well.  Once, when our black tank was pretty full and we had traveled most of the day to our next site, I took the cap off the black flush connection and a small amount of fluid came out.  I though it had an odd smell.  So, I don’t know if the backflow valve failed or something else happened, or if it was just my imagination.   After that, we just decided to keep it closed until we are putting water through the flush connection.  I don’t know if newer trailers have the same valve or not.  Mike

[Ray and Susan Huff]

2 hours ago, Mike and Carol said:

On some Olivers there is a valve under the back dinette seat that opens and closes the black flush line.  For years we used to just keep it open because there is a back flow on that line as well.  Once, when our black tank was pretty full and we had traveled most of the day to our next site, I took the cap off the black flush connection and a small amount of fluid came out.  I though it had an odd smell.  So, I don’t know if the backflow valve failed or something else happened, or if it was just my imagination.   After that, we just decided to keep it closed until we are putting water through the flush connection.  I don’t know if newer trailers have the same valve or not.  Mike

Thanks . . . . . . I'll ask about this when we pick up our Ollie.