Hymer B594 1996 - waste / fresh water systems advice (1 Viewer)

Triple7

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I've now been on my travels for nearly a month and I'm currently lurking in the Lisbon area. I've tried visiting Sintra a few times but if there is a less "motorhome friendly " place on the planet I'd be surprised. Sintra is stunning though so I may return. Lol

So far everything has gone very smoothly and I continue to be delighted with the Hymer. I do have a few minor issues with water management following my initial issue with the boiler trip switch(thanks again to those what sorted me out!)

I don't think my gauges work properly or if they do I've no idea what they are telling me.

My first question is about the waste water drain. Mine flows very slowly (about the speed of a slow tap) and takes a few hours to empty the tank (although I've no idea how full it is in the first place) Is this normal?

This morning I decided to unscrew the large circular hatch under the tank expecting 20 years of "crud" to slosh out but it was totally dry with just a circular polystyrene insert. What lies above that I couldn't see. What if anything should I be doing with this hatch?

I also have an issue with the fresh water. Water appears in the shower tray and I'm not sure from where or why. My guess is the tank has a leak when it's fairly full but I'm not certain. I don't think the water is coming from the taps but it's possible it might be coming in from the outside shower located in the toilet cassette hatch.

If any of this jogs the memory of anyone with Hymer plumbing experienes I'd be grateful for any insights.

Thanks in advance.
 

JeanLuc

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Waste tank
Above the polystyrene disc (insulation) is a screw-in plug which is probably like the one on your fresh water tank. Unscrew this and be prepared for a torrent. I suspect the inside of your tank is coated in crud and the waste gate valve also. Get a hose up into the tank and give it a good flushing out. It's also worth cleaning the rods of the tank level sensor while you have access. This is a four-rod system: the same as fitted in the fresh tank. the rods get coated in muck and this can stop the gauge working. I cleaned the rods on mine using washing up liquid and a sponge scourer pad. Be prepared to use something like Cif if necessary. When reassembling, ensure you seat the neoprene washer correctly around the tank plug. Mine leaked and I ended up putting a bit of bathroom silicone sealant around it for good measure. It's not that difficult to twist and break the seal next time you clean it out. I have done this major cleaning project every two or three years.

You may still need to flush the system with cleaner once everything is back together. I make a habit of putting a good dose of bio washing liquid down the sink waste every few days when we are away. Then wait until we have drive with a decent waste water load to ensure agitation before emptying. When we get home and I empty the waste tank for lay-up (even a few weeks) I use the Hymer-supplied flexi-waste hose to connect to our drain and after the tank is empty, I lift the said hose in the air and put quite a lot of fresh water 'up the spout' with a garde hose before once again letting the tank drain to waste.

Fresh water in the shower tray

Not sure about this one. Can you describe the layout of your shower room? For example: how is the shower mixer fitted - is there a curved trunking hiding the supply pipes; does yours have a swing-wall shower?
 
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I did read somewhere, when the waste water tank is full then the water backs up the pipe work to the lowest point. Which would be the shower tray. This might or might not be the reason for water in your tray.

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JeanLuc

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I did read somewhere, when the waste water tank is full then the water backs up the pipe work to the lowest point. Which would be the shower tray. This might or might not be the reason for water in your tray.
That's true - if the waste tank is full, any further discharge into it will cause water to come up through the shower waste traps.
 
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Triple7

Triple7

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Waste tank
Above the polystyrene disc (insulation) is a screw-in plug which is probably like the one on your fresh water tank. Unscrew this and be prepared for a torrent. I suspect the inside of your tank is coated in crud and the waste gate valve also. Get a hose up into the tank and give it a good flushing out. It's also worth cleaning the rods of the tank level sensor while you have access. This is a four-rod system: the same as fitted in the fresh tank. the rods get coated in muck and this can stop the gauge working. I cleaned the rods on mine using washing up liquid and a sponge scourer pad. Be prepared to use something like Cif if necessary. When reassembling, ensure you seat the neoprene washer correctly around the tank plug. Mine leaked and I ended up putting a bit of bathroom silicone sealant around it for good measure. It's not that difficult to twist and break the seal next time you clean it out. I have done this major cleaning project every two or three years.

You may still need to flush the system with cleaner once everything is back together. I make a habit of putting a good dose of bio washing liquid down the sink waste every few days when we are away. Then wait until we have drive with a decent waste water load to ensure agitation before emptying. When we get home and I empty the waste tank for lay-up (even a few weeks) I use the Hymer-supplied flexi-waste hose to connect to our drain and after the tank is empty, I lift the said hose in the air and put quite a lot of fresh water 'up the spout' with a garde hose before once again letting the tank drain to waste.

Fresh water in the shower tray

Not sure about this one. Can you describe the layout of your shower room? For example: how is the shower mixer fitted - is there a curved trunking hiding the supply pipes; does yours have a swing-wall shower?
Many thanks for the info.JeanLuc. It sounds like a very messy job to clean the tank. Is it a case of being on the flat of your back right underneath or are there any clever tricks?

On further investigation I think the source might be in the cassette hatch. It is very wet in there but it's definitely fresh water. All the pipework connections are sound but there might be a drip coming from a plastic moulding "hole" (there are actually two, one in picture 3 and one at the back) Are these some sort of drain or overflow? From where?

Hopefully you can also see two other pics of the bathroom and another pic of the hatch.

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Triple7

Triple7

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I did read somewhere, when the waste water tank is full then the water backs up the pipe work to the lowest point. Which would be the shower tray. This might or might not be the reason for water in your tray.
Luckily it's definitely fresh
 
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Triple7

Triple7

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Ive now flushed out the tank. There was very little crud in there so I'm guessing it's the waste exit which is the problem. Is there a value? When I back flush the pipe it presurises after a few seconds. I will fill the tank and try JeanLucs tip using washing liquid. If that fails I think I will just put up with it unless there are any other suggestions.

The fresh water leak is a very slow one. I suspect it's something in the cassette hatch. Possibly the shower so I will just keep an eye on it and see what develops.

Thanks guys for your help :)

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TheBig1

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having fixed several vans with this issue, I recommend unscrewing the clamp and pull off the drain off pipe. often the waste matter forms a concretion which will not dissolve with water or soap. there are 2 answers either manually scrape out or replace the pipes
 
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Triple7

Triple7

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having fixed several vans with this issue, I recommend unscrewing the clamp and pull off the drain off pipe. often the waste matter forms a concretion which will not dissolve with water or soap. there are 2 answers either manually scrape out or replace the pipes
Thanks for the advice. I will see if I can get decent access to the clamp

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Triple7

Triple7

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Can you take the valve of or take it apart, it sounds like the valve is blocked - not allowing water in or out
That's what I think the problem is. Too much of a job for me while I'm on the road unfortunately.
 
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Triple7

Triple7

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nearly all domestic wastes are plastic, used as directed caustic drain cleaner won't attack plastic or rubber.. ...there are two risks..

overheating and melting the plastic.. going cold and solidifying..

try the stiff wire idea first ..
Thanks that's good to know..... Won't give up just yet!
 

JeanLuc

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Your pictures indicate a different layout to mine so I'm not sure about the fresh leak. I think you may have got the best idea of where it is coming from.
Regarding waste, if you are getting back-pressure when trying to flush water up the waste exit that suggests the valve is blocked. I think you need to wait until you can get at the valve and try to clear it.
I'm not sure from your report above whether you removed the access plug at the bottom of the tank and flushed it through there. If not, then yes, it can be a messy job and you have to lie on your back to do it. I park at the point where our drive turns from up to down hill so the back is angled up a bit.
 

TheBig1

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levelling ramps can also be used to aid access, but make sure you leave the van in gear, handbrake on and chock the wheels

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Triple7

Triple7

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Your pictures indicate a different layout to mine so I'm not sure about the fresh leak. I think you may have got the best idea of where it is coming from.
Regarding waste, if you are getting back-pressure when trying to flush water up the waste exit that suggests the valve is blocked. I think you need to wait until you can get at the valve and try to clear it.
I'm not sure from your report above whether you removed the access plug at the bottom of the tank and flushed it through there. If not, then yes, it can be a messy job and you have to lie on your back to do it. I park at the point where our drive turns from up to down hill so the back is angled up a bit.

Yes I bit the bullet and removed the plug as much as I have liked to put it off. All was as you described but I suspect the previous owner cleaned the tank before he sold it as there was only a small bit of crud that came out straight away and no amount of rinsing produced more.

The freshwater leak might be the external shower but there was a lot of water in the indents below the cassette and on the left hand side which would point to it coming from elsewhere ( from above). Any idea what those plastic tube moldings in my pic are for? They look like they could be drain ducts
 
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Triple7

Triple7

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levelling ramps can also be used to aid access, but make sure you leave the van in gear, handbrake on and chock the wheels
When you are new to motorhoming levelling ramps don't seem that important (at least in my case) so they are not on board....they will be as soon as I can find some as it didn't take me long to regret the omission :)
 

TheBig1

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Triple7

Triple7

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Thanks for the link. Im hoping to pick some up locally. Currently in Lisbon but will be heading for Spain tomorrow so shipping isn't really an option unfortunately.
 
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Triple7

Triple7

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I've traced the source other fresh water leak to the internal shower tap which is located about the same level as the top of the water tank.

The screw thread of the black plastic housing was broken, hence the leak. I've managed to glue it back together so the white plastic top will again screw in. But water continues to leak out.

My question is ; what stops the water from coming up the sides of the beige ceramic peice? Is it some sort of grease or am I missing a gasket?

Hope the question makes sense and any help would be very welcome as having found the problem (which was a minor one), by taking the tap out its now a major one!

Many thanks.
 

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i think its just the o rings on the base of the ceramic cartridge that make the water seal

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Triple7

Triple7

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i think its just the o rings on the base of the ceramic cartridge that make the water seal
Many thanks mitzimad. I was nervous about over tightening the repair if there was something else involved. Armed with your info I tightened it up more and it's now working as it should. Cheers mate :)

Ps - For anybody who comes along later with a similar grey water slow drain problem, I put a few shots of drain cleaner down the sink and it has helped but it still takes the tank about an hour to drain. Not sure if it's designed that way or not.... But I can live with it!
 

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