To empty the Toilet Chemical flush or not?

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Jul 29, 2022
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Last September we travelled around the North East visiting lots of different places and everytime we packed up and moved on I always emptied the toilet cassette then drain down the pink flush in a 2litre bottle ready to be used again.
I don't like the idea its slushing around as we travel and that goes for all fluids...well apart from all the booze on board ofcourse!
 
Nov 11, 2009
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Last September we travelled around the North East visiting lots of different places and everytime we packed up and moved on I always emptied the toilet cassette then drain down the pink flush in a 2litre bottle ready to be used again.
I don't like the idea its slushing around as we travel and that goes for all fluids...well apart from all the booze on board ofcourse!
Any free surface effect of water “sloshing” around is negligible in the overall stability of the caravan. What could be more important is the weight of the fluids on payload and weight distribution.
 
Jan 20, 2023
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In years gone by I used to travel with the flush tank full, but stopped after noticing our (at the time) new Sterling Eccles Jewel leaked flush water into the toilet bowl after a journey.
 
Nov 16, 2015
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In years gone by I used to travel with the flush tank full, but stopped after noticing our (at the time) new Sterling Eccles Jewel leaked flush water into the toilet bowl after a journey.
Our Sterling Eccles Jewel was, a fantastic caravan, loved it, exchanged it for a New Coachman 545. Then a Coachman 560.
 
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Jan 20, 2023
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Our Sterling Eccles Jewel was, a fantastic caravan, loved it, exchanged it for a New Coachman 545. Then a Coachman 560.
Ours was our first ever brand new caravan bought in June 2002. It was one of the first fixed bed single axle layouts with a usable bathroom (not a wet room). We part exchanged it in 2007 for an Elddis Avante 540 that gradually fell apart in the 2 years we owned it.
 
Mar 14, 2005
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For free surface effect is a concern but the reality is even under difficult driving conditions the water contained in a toilet cistern or a holding tank should not have enough "free surface" area to generate the momentum and thrust in the mass of liquid to exceed the wall fixings.

If you driving is generating enough momentum to cause such failures then it's very likely other things will also be failing and getting damaged.
 
Jul 18, 2017
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For free surface effect is a concern but the reality is even under difficult driving conditions the water contained in a toilet cistern or a holding tank should not have enough "free surface" area to generate the momentum and thrust in the mass of liquid to exceed the wall fixings.

If you driving is generating enough momentum to cause such failures then it's very likely other things will also be failing and getting damaged.
I guess you have never had to brake sharply for some idiot cutting across in front of you. I would rather not risk testing the strength of bolts holding the tank in place. Plus of course the manufacturers do not advise travelling with the onboard tank full of water. as mentioned by OC that is also 40kg that east into your payload.
 
Nov 11, 2009
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However 20-30 litres of water sloshing around could rip an onboard tank off its mountings.
I was addressing Slowtow at #26 and his 2 litres of flush that he drained. In the flush or cassette tanks each is less than 20 litres.. The discussion has now morphed to onboard water tanks.
 
Nov 11, 2009
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Which is a good thing for clarification.
In all my years on this Forum and visiting other forums I have never heard of an inboard water tank becoming detached from its fixings. I don’t know how many caravanners travel with them full or less full. But I suspect some will do so. Are we looking for problems so unlikely to not really be relevant. It’s dead easy to ameliorate concerns; just empty the tank or keep a much reduced ready use quantity in it.
 
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Mar 14, 2005
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I guess you have never had to brake sharply for some idiot cutting across in front of you. I would rather not risk testing the strength of bolts holding the tank in place. Plus of course the manufacturers do not advise travelling with the onboard tank full of water. as mentioned by OC that is also 40kg that east into your payload.
You guessed wrong again.

It wouldn't be the bolts that fail, it would be the caravan structure.

I am on record of advising draining before traveling. But the fear of sloshing liquids doing damage in caravans is unfounded, as what the liquid is contained will limit it's not the freedom to slosh, it's the mass, as you say, under extreme manoeuvres that will do more damage.
 
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Jun 20, 2005
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The general consensus and indeed that of Thetford is that no fluids should be contained within their toilet. The flush contains 9.8 ltr water whilst when full to capacity 19 ltr is in the holding tank .. Say 29 litres which at 1 kgs per litre is 29 kgs. Over half of one hundred weight. Not an inconsiderable amount to factor into your loads. Best drive when all empty imo.
 
Jul 18, 2017
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Just to different our "flush" tank holds 40litres of water as the flush water comes from the onboard tank. We carry a 5ltr bottle with water in it to flush the loo if we need to go while travelling.
 
Jul 29, 2022
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Our Sterling Eccles Jewel was, a fantastic caravan, loved it, exchanged it for a New Coachman 545. Then a Coachman 560.
There doesn't seem a lot of Coachman 560's around especially the later models.
We were pitched up on numerous sites from our tour of the north east last September and only spotted one earlier Pastiche version. The main reason we chose the french bed '560 was its compact 24foot shipping length.
 
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