Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
 

Go Back   Montana Owners Club - Keystone Montana 5th Wheel Forum > GENERAL DISCUSSIONS > General Discussions about our Montanas
Click Here to Login

Reply
 
Thread Tools Search this Thread Display Modes
 
Old 03-06-2007, 04:15 AM   #1
patodonn
Montana Master
 
Join Date: Jun 2003
Location: Full Timer
Posts: 918
M.O.C. #331
That pesky label - Black tank flush system

Well, you know that pesky placard next to the flush connector that days "Don't do it" unless the tank valve is open? Here is what could happen, and almost did to us.

Flushing the black tank, and, as always, with the black tank valve closed to refill via the fush system to get a good "second" flush. I always use 7 minutes from empty, which is always safely below "full" in our rig. Got distracted with something and it went 10+ min. Now, THAT is overfull!

Where did it go? Not really absolutely certain, but the toilet assembly and seal held and it didn't leak into the bathroom, (thank God). It appeared to start to fill up the black tank vent pipe. When I shut off the water in a panic and then opened the black tank valve, the pressure of the effluent was enough to crack my 3 yr old and somewhat brittle sewer hose in two places and leak significantly for about 1 min. It looked like I had several feet of water column pressure behind it at the start. Bit of a mess to clean up afterward, and needed a new hose, but, other than that, got away without damage to me, the surroundings, or the Monty (except the sewer hose)

I was REAL lucky! Tank is not leaking and nothing overflowed, but I can visualize black tank water pouring down from the roof of the Monty, or the tank rupturing from the pressure of a 10 foot column of liquid in the vent pipe.

Think I'll be a bit more attentive to the task at hand next time. Word to the wise....be REAL careful and attentive if you are going to use this flushing technique.

Best
 
patodonn is offline   Reply With Quote
Old 03-06-2007, 04:46 AM   #2
bncinwv
Montana Master
 
Join Date: Feb 2007
Location: Winfield
Posts: 7,327
M.O.C. #6846
Newby question - What is the recommended procedure for doing this?? Does the flush system actually spray some percentage of the tank walls or is it for backfilling? TT never had this option so it was buckets of hot water in the toilet to complement flushing. I did this with valves closed so can understand the practice of doing likewise with the flush system (also understand the dangers!!). Seeking opinions and experience as to different methodologies. I know everyone will have their own ways, as I probably will after experimenting, but still would appreciate input from the experienced!!
Bingo
__________________

Bingo and Cathy - Our adventures begin in the hills of WV. We are blessed by our 2014 3850FL Big Sky (previous 2011 3750FL and 2007 3400RL) that we pull with a 2007 Chevy Silverado Classic DRW CC dually.
bncinwv is offline   Reply With Quote
Old 03-06-2007, 05:18 AM   #3
Parrothead
Montana Master
 
Join Date: Aug 2004
Location: Fallon
Posts: 6,064
M.O.C. #1989
Send a message via MSN to Parrothead
Bingo
You can hear the spray when you are doing the black tank flush. We close the valve for about 3 or 4 minutes and then open it. Sometimes you have to do this several times before the water is clear. If you don't keep track of the minutes, when you can't hear the spray anymore, OPEN THE VALVE. This means it is full or almost full. Don't let anything interrupt you when doing this. If someone comes up to talk, shut off the water. We do this together so we can monitor each other.
Happy trails..................
Parrothead is offline   Reply With Quote
Old 03-06-2007, 05:31 AM   #4
bsmeaton
Montana Master
 
Join Date: Aug 2006
Location: Lone Tree
Posts: 5,615
M.O.C. #6109
Lucky man PJ! Almost RV Movie II!

At least now you know your toilet seal is tight. My luck, one of the kids would have been using the bathroom and would have got a big surprise when they went to flush .
bsmeaton is offline   Reply With Quote
Old 03-06-2007, 05:48 AM   #5
Crossthread
Montana Master
 
Join Date: Oct 2006
Location: Arroyo Grande
Posts: 504
M.O.C. #6460
Been there, done that, except when I noticed it, it as coming out the door. Had a call that a family member was having 3 stints put in, got really distracted. Luckily,it was the 3rd good rinsing of the black tank,still wasn't pleasant.Now I won't take my hand off the faucet without turning it off.In plumbing, I think that you get 1/2 lb.water pressure for each foot of elevation,so there wouldn't have been much static pressure.Also, I've been told not to use over 40 lb pressure on the flush system, it will cause the air-gap valve to stick.As to where the water went, it could have been a misleading reading due to the water circulating in the tank.
The question as to the procedure,the newer rv's have an airgap valve to prevent the water from siphoning into the water supply source.The older ones have it direct into the tank.It has holes,or ports in the end of it to direct spray around to hopefully rinse the tank. I drain the tank, flush 2 times,put in 1 gal.of water, put Unique rv digester in, leave it till the next time.Bill
Crossthread is offline   Reply With Quote
Old 03-06-2007, 06:30 AM   #6
rlrich
Seasoned Camper
 
Join Date: Feb 2006
Location: Carroll
Posts: 70
M.O.C. #5319
Been there - done that plus some. I was using my Flush King to refill and backflush. I hollered at the wife to look into the toilet and see how full it was getting. She hollered back that she couldn't open it (in retrospect I truly thank God for that). About that time I felt water sprinkling down the back of my neck. Ooops! It's a good way to clear any blockages that may be in the ventpipe. That was my explanation to the surrounding crowd anyway.
rlrich is offline   Reply With Quote
Old 03-06-2007, 06:58 AM   #7
Connorsmom
Montana Fan
 
Join Date: Dec 2006
Location: Owendale (Bad Axe)
Posts: 380
M.O.C. #6592
I'm really confused here. As I said on a previous thread...when I did my walk thru, the guy said NEVER use the black tank flush without having the valve open. He said too much pressure will cause all that good stuff to shoot right out the vent pipe. He told me a few horror stories of customers who didn't open the valve, and the nightmare that ensued. Isn't it awfully risky to do this??? Personally, if I need the tank THAT clean, I'll put a hose in the toilet and fill it with water and let it sit in there for a few hours, then drain it. Man, just the possibility of that happening makes me wanna hurl. Yikes.

Jan
Connorsmom is offline   Reply With Quote
Old 03-06-2007, 08:25 AM   #8
hazmic
Montana Master
 
Join Date: Nov 2005
Location: cedar rapids
Posts: 703
M.O.C. #4962
When performing this you must be ON THE BALL the whole time. Do not wonder off or get distracted at any time while doing this. If you do SHUT OFF THE WATER. I don't think you had that much pressure build up because it was venting to the outside as you had a bad or weak hose. If a few years old the sun rots or deteriorates them[sewer hose]. Big label should say Pay Attention!!!!!
hazmic is offline   Reply With Quote
Old 03-06-2007, 09:39 AM   #9
Parrothead
Montana Master
 
Join Date: Aug 2004
Location: Fallon
Posts: 6,064
M.O.C. #1989
Send a message via MSN to Parrothead
Jan
I think that tell you that so you won't run it so long it will fill up. Running it a couple of minutes is not going to fill it up. Like I said you can hear the spray. It doesn't seem to do much if the valve is open all the time.
Happy trails....................
Parrothead is offline   Reply With Quote
Old 03-06-2007, 11:37 AM   #10
rickety
Montana Master
 
Join Date: Oct 2005
Location: Caldwell
Posts: 825
M.O.C. #4855
Bingo, ditto what every one else has been saying. DON'T GET DISTRACTED!! Three or four minutes back flush on and EMPTY tank will not hurt anyting. My friend got distracted, and blew his black tank. Cracked it laterally across the bottom and it was really really nasty!!!!!!!
By the way, welcome aboard and enjoy the forum. You will learn so much here!!!!! I have!!!
rickety is offline   Reply With Quote
Old 03-06-2007, 11:38 AM   #11
Connorsmom
Montana Fan
 
Join Date: Dec 2006
Location: Owendale (Bad Axe)
Posts: 380
M.O.C. #6592
He didn't mention anything about filling it up. He said that when the valve is closed, it allows far too much pressure to build up. What he was telling me is that it's the pressure that pushes the "stuff" up causing it to spray out the vent, not the tank getting too full. I didn't see anything in my paperwork regarding this. Yea, I know big surprise there. The owners manual and paperwork given with these units is a joke. Anyway, I gotta research this issue and see what the recommendations are.

Jan
Connorsmom is offline   Reply With Quote
Old 03-06-2007, 12:10 PM   #12
kjtogo
Established Member
 
Join Date: Jan 2007
Location: Dumfries
Posts: 23
M.O.C. #6667
I used ours last weekend and just monitored the inside gauge and opened the valve when the gauge hit 2/3. I did take a few back flushes so to say until the water ran clear.
kjtogo is offline   Reply With Quote
Old 03-06-2007, 12:30 PM   #13
Parrothead
Montana Master
 
Join Date: Aug 2004
Location: Fallon
Posts: 6,064
M.O.C. #1989
Send a message via MSN to Parrothead
Jan
If that was true then when you have the valve closed all the time while parked and using it, stuff would be pushed up into the vent. Remember some of these techs have never camped in an RV or owned one. We hear all kinds of stories from them. We've been using our method for several years without a problem. Maybe none of us said, you empty the tank first before you use the black flush.
Happy trails...
Happy trails...
Parrothead is offline   Reply With Quote
Old 03-06-2007, 03:17 PM   #14
The Oldguard
Montana Master
 
The Oldguard's Avatar
 
Join Date: Dec 2004
Location: YUMA
Posts: 861
M.O.C. #2625
Jan,
Like the sign say’s “No Lifeguard On Duty”!! Swim at your own risk!
The Oldguard is offline   Reply With Quote
Old 03-06-2007, 04:05 PM   #15
Bluegill
Montana Fan
 
Join Date: Aug 2006
Location: Cypress
Posts: 333
M.O.C. #6121
Hey PJ, Thanks for thread about this.
I have been using the same technique to flush my black water tank. And so far I have not had that happen to me. BUT, it is always on my mind when I flush. When it was 17 degrees outside I would run inside for about 8 minutes (playing XBox 360) and then run back out to drain again.
Glad to here it all "came out" good in the end.
Bluegill is offline   Reply With Quote
Old 03-06-2007, 08:04 PM   #16
patodonn
Montana Master
 
Join Date: Jun 2003
Location: Full Timer
Posts: 918
M.O.C. #331
kjtogo:

Many of us have learned from sad experience that the gages are worse than useless. They may start out OK, but sooner, rather than later, they give incorrect readings. Not only do they not tell the correct story, they lie to you! If you rely on a gage reading for liquid levels in a tank, the only thing you know for sure is that it is probably wrong.

As a test, we have, several times, filled the black tank using the flush system, one person watching inside, one manning the outside faucet. After several trial runs we established that it takes 8+ minutes at 50 psi water pressure to fill the tank from empty using the tank flush system. We now use 6-7 min as a safe "fill time" for our second and third flushing rinse of the black tank. We do it at about once a week this way while "full timing". Lots of postings available via the Search function of the Forum which discuss all of this stuff.

Don't trust those gages!
patodonn is offline   Reply With Quote
Old 03-07-2007, 02:53 AM   #17
Bluegill
Montana Fan
 
Join Date: Aug 2006
Location: Cypress
Posts: 333
M.O.C. #6121
My gauges worked for a couple of months, now they all light up all the time ... full or empty.
so i empty once a week with two of us,,, or every two weeks with just me on board.
Bluegill is offline   Reply With Quote
Old 03-07-2007, 03:22 AM   #18
richfaa
Montana Master
 
Join Date: Jan 2005
Location: North Ridgeville
Posts: 20,229
M.O.C. #2839
He was wrong..The black tank IS vented via that pipe that sticks out of your roof. He was right in suggesting bad things CAN happen if you do not pay STRICT attention to what you are doing. It is better for them to say DON"T DO IT EVER.. If you did that nothing bad would ever happen. Of course you do not want it to over fill/. In a previous camper I was cleaing the black tank using dish wash fluid and wound up with tons of bubbles flowing down the side of the camper (How many of us have done that)??? I can tell just by the sound of the spray going into the tank how full it is..If the water gets over the spray nozzleyou will not be able to hear it at all.. Just be very careful do not be distracted.
richfaa is offline   Reply With Quote
Old 03-07-2007, 11:37 AM   #19
rickety
Montana Master
 
Join Date: Oct 2005
Location: Caldwell
Posts: 825
M.O.C. #4855
Just as a point of information. The flush spray head mounts 1 1/2 inches below the very top of the tank, on the shallow end. The end of the sprayer does NOT roatate, but had only four spray hole about 1/16 dia. arranged at wierd angles around the circumference of the nozzle. The tank is shallow at the passenger side and deep at the driver side. The guage sensors are mounted on the deep end and spaced evenly up the side with the full reading at about 1 inch from top, depending on which "old world craftsman" was working that day. How do I know? says you, replaced one for a friend says I. NOT fun!!!! nast smelly icky yucky and all the other words you can think of....
rickety is offline   Reply With Quote
Old 03-07-2007, 01:28 PM   #20
richfaa
Montana Master
 
Join Date: Jan 2005
Location: North Ridgeville
Posts: 20,229
M.O.C. #2839
Rick speaks with a straight tongue. I looked those tanks over on the rally factory tour looking for reasons that they leak, guages do not work, etc. His description is perfect.
richfaa is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Black Tank Flush System maximo General Discussions about our Montanas 15 01-27-2014 09:00 AM
Black Tank Flush System Update vibetech1 Montana Problems, Problem Solving & Technical Help 10 10-26-2013 10:53 AM
BLACK TANK FLUSH SYSTEM Larry-P General Discussions about our Montanas 5 09-18-2012 10:34 AM
Black Tank Flush drphelps General Discussions about our Montanas 7 10-27-2008 06:03 PM
Black Tank Flush DHenry Additions & Improvements 0 05-26-2004 03:52 AM

» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by Montana RV, Keystone RV Company or any of its affiliates. This is an independent, unofficial site.


All times are GMT -6. The time now is 02:35 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.