Free 7 Day Trial RV GPS App RV Trip Planner Campground Reviews RV Maintenance Free 7 Day Trial ×

Go Back   Keystone RV Forums > Keystone Fleet | Keystone RV Models > Travel Trailers
Click Here to Login

Thread Tools Display Modes
Old 08-21-2016, 09:21 PM   #1
Junior Member
Join Date: Sep 2015
Location: Pennsylvania
Posts: 21
Tank flush problem

I have a 2016 Cougar 28RBS. On our first trip out in April I tried to use the tank flush. Nothing happened. It seemed as if the water was just stopping. I checked the vacuum breaker and found it installed backwards. Plus it wasn't working anyway. I tried to blow through it but it was seized shut. Instead of taking a 3 hr drive to take it in to the shop I replaced the vacuum break with a pex elbow so it would go straight through. Tried to flush again this weekend. Nothing. It acts like there is another valve or something stopping water flow. When I first checked the vacuum break one side did have pressure so I figured that's where the problem was. So now either I have a blockage after the vacuum breaker or I'm missing something. Is it just a straight connection with no valves? I really hate to make that 3 hr drive and lose my camper for the next month while it waits it's turn.

Sent from my iPhone using Tapatalk
Newman252 is offline   Reply With Quote
Old 08-22-2016, 03:38 AM   #2
Senior Member
Join Date: Jul 2015
Location: New Hampshire
Posts: 423
I have the same issue. I assumed that the output was blocked so I left the tank full of water overnight...didn't help. I'm beginning to think that like another owner, I have a kink on the line.

2015 Ram 1500 Ecodiesel
2015 Cougar 26RBI
bill-e is offline   Reply With Quote
Old 08-22-2016, 05:37 AM   #3
malabarbob's Avatar
Join Date: Apr 2016
Location: Okeechobee, FL
Posts: 30

Same here on my 248RKS Bullet. First time out, no black drained. Took it to the dealer and he said he drained it and it was OK. Got it home, looked into toilet and saw wads of toilet paper (yes, we use RV stuff). Pulled it out with a grabber, added lots of chemical. Liquid seems to run thru OK. We have a 5 day trip coming up. Will try with just liquids and hope for the best.
Question - is what I see looking down into the toilet, the black tank or is that just a holding area until it reaches the height of the black pipe that then leads to the black tank?
Bob & Sue Rowan
Okeechobee, FL
2015 Keystone Bullet 248RKS
Towed with a 2016 F-150 Laredo with auto backup
Travel with our "Morkie" - Zoe
malabarbob is offline   Reply With Quote
Old 08-22-2016, 05:58 AM   #4
Site Team
JRTJH's Avatar
Join Date: Mar 2011
Location: Gaylord
Posts: 21,648
The toilet dumps "directly into the black tank" in almost all travel trailers. In fifth wheels, there may, on some models, be an offset 3" or 4" black pipe leading from the toilet to the top of the black tank.

What you see, when looking down into the toilet on your trailer is the contents of the black tank. The toilet paper "wads" that you pulled out were "resting on the black tank floor".

The "key to success" with solids in a black tank is LOTS OF WATER. You need enough water (in the toilet bowl) to "flush the solids away from directly under the toilet" and when dumping, you need enough fluid to sweep the floor of the black tank clean (sunami action).

If I were you, I'd spend a considerable amount of time at a full hookup site or at a dumping station. Start by filling your black tank "brimming full" by flushing the toilet repeatedly. Once you are full, then go outside and pull the tank valve. Let it drain completely, then go inside and fill the tank again. Repeat this process until you don't see any "solid material" flowing into the campground sewer. Once empty, if you have any problems with your level gauges, you might consider an "enzyme digester" and another "full tank of clean water" to "sit and soak" for a few days.

After you're clean, you can "start fresh" with about 5 gallons of water in the black tank and remember that you need to "fill the bowl with adequate water" when you flush solid waste into the tank.

Think about the fact that most black tanks are only about 8" deep. If you "dump a solid mass" without adequate water to "splash it away", that mass will sit under the toilet "hole in the floor" and after several "solid dumps" you'll get that "pyramid of poo" that you described.

A good "old wive's saying" to follow is, "Dilution is the solution to pollution"....

more water, More Water, MORE WATER !!!!!

ADDED: Remember that any enzyme cleaner can only clean the parts of the tank on which it is exposed, so adding 5 gallons of water and a pack of "enzyme cleaner" and letting it sit will NOT clean the tank walls or top. The only parts of the tank that are exposed to the enzyme in that situation is the floor. So, if you want to clean your tank walls, the "black tank flush spray head" and the tank level sensors, you'll need to completely fill the black tank with water, add the enzyme packet and let it sit "COMPLETLEY FULL" for a period of time.

2015 F250 6.7l 4x4
2014 Cougar X Lite 27RKS
JRTJH is offline   Reply With Quote
Old 08-22-2016, 10:38 AM   #5
Senior Member
ThePressureIsOn's Avatar
Join Date: Aug 2011
Location: Battle Creek
Posts: 163
We also have a 248RKS, check out post #6.
Bob & Sarah
2013 Bullet 248RKS (Taj Mahaul)
2013 Silverado 2500HD, 6L, 3.73 (Blizzard)
ThePressureIsOn is offline   Reply With Quote
Old 08-22-2016, 11:05 AM   #6
Senior Member
Join Date: Jul 2015
Location: New Hampshire
Posts: 423
Originally Posted by ThePressureIsOn View Post
We also have a 248RKS, check out post #6.
Different issue. We're talking about the fresh water tank flush nozzle being clogged in some way.

2015 Ram 1500 Ecodiesel
2015 Cougar 26RBI
bill-e is offline   Reply With Quote
Old 08-22-2016, 01:45 PM   #7
Senior Member
14george's Avatar
Join Date: Jan 2015
Location: West Virginia
Posts: 1,270
Had the same problem took to dealer worked fine and still working. Think it was a kink in line
Navy 1980-1984
14george is offline   Reply With Quote
Old 08-23-2016, 01:23 PM   #8
Senior Member
Join Date: Jul 2015
Location: New Hampshire
Posts: 423
I just looked inside the bottom, no kink, must be a clogged nozzle.

2015 Ram 1500 Ecodiesel
2015 Cougar 26RBI
bill-e is offline   Reply With Quote
Old 09-01-2016, 01:41 PM   #9
Junior Member
Join Date: Jul 2016
Location: East Bay, CA
Posts: 4
We have a new Bullet 272BHS with the hose connection on the outside. Our second trip I tried to use it. I connected the hose, turned it on, and it just sprayed water all over from the connection on the outside. I heard no water going into the tank, and it seemed as if the valve was stopping the water from going into the tank.

I had 2 people behind me waiting to dump so I just disconnected and used some water down the toilet into the tank to try and flush. So frustrating.

Why is it so hard for these things to work correctly?

Is there anything that needs to be done to get the valve to work? Or is it simply just connect a hose and turn on? There is a warning sign above the connection that says it could cause an "unsanitary" condition. I forget what it says exactly but it concerned me.
SFGiantsFan925 is offline   Reply With Quote
Old 09-01-2016, 07:18 PM   #10
Site Team
chuckster57's Avatar
Join Date: Jul 2014
Location: Modesto
Posts: 14,336
I've seen the vacuum breaker installed backwards quite a few times. Can't say kinked line is common, but plugged sprayer has happened a few times.

These things can and do work correctly when the dealer does a proper PDI. It never ceases to amaze me how many dealers will skimp on the PDI, and just "get 'em over the curb". We routinely see keystone products purchased from another dealer, that when we start warranty repairs it's obvious the PDI wasn't done correctly or at all.

Okay, I'm done. I'll get off my soapbox and watch TV.

2012 Copper Canyon 273FWRET being towed by a 1994 Ford F350 CC,LB,Dually diesel.
Airlift 5000 bags, Prodigy brake control, 5 gauges on the pillar.Used to tow a '97 Jayco 323RKS.

Now an RVIA registered tech. Retired from Law enforcement in 2008 after 25+ yrs.
chuckster57 is offline   Reply With Quote
Old 09-01-2016, 07:34 PM   #11
Senior Member
bsmith0404's Avatar
Join Date: Mar 2014
Location: Las Cruces
Posts: 3,041
Listen closely to see if you can hear the water spraying inside the tank. Open the toilet and listen. I think many people believe the blank tank flush isn't working because they don't see water running out of the sewer hose. Not saying that is your case, but a possibility. Remember, the hose going in is 5/8", the amount of water it actually dumps into the tank is further reduced by the ability of the spray head. Your sewer hose is 3", you will only get a small trickle out of the hose. Personally, shut the black tank waste gate and let the tank fill up a bit to create a stronger out flow to help remove waste. Just don't forget about it and flood the bathroom.

2013 Alpine 3500RE
2019 Silverado 2500HD Duramax
U.S. Air Force Retired (25 yrs)
RV Sales Consultant
bsmith0404 is offline   Reply With Quote

Thread Tools
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

Powered by vBadvanced CMPS v3.2.3

This website is not affiliated with or endorsed by the Keystone RV Company or any of its affiliates in any way. Keystone RV is a registered trademark of the Keystone RV Company.

All times are GMT -8. The time now is 04:25 AM.

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2021, vBulletin Solutions, Inc.