bob b Posted March 28, 2012 Share Posted March 28, 2012 The electrical connector indicating the waste level on my tank has corroded and come adrift. Would I be correct in assuming that I have to drop the tank to replace the connector. It would appear that the screw has a nut on the other end....which is inside the bleedin' tank.Can somebody please tell me that there is a simple way of replacing the dicky connector! Link to comment Share on other sites More sharing options...
Guest Tracker Posted March 28, 2012 Share Posted March 28, 2012 Can you file of the top of the screw/bolt and carefully solder it back on - not too much heat though! Or drill a fine hole down through the washer and tank skin, taking care not to go too deep and hit anything inside the tank and affix the lead with a round end terminal and short self tapping screw? Link to comment Share on other sites More sharing options...
bob b Posted March 28, 2012 Author Share Posted March 28, 2012 I don't think I'll be able to generate enough heat to solder a connection back without doing some damage. The screw head is quite near the bodywork, although you can't see that from the photo, so there isn't enough room to get a drill in there. Thanks anyway Richard.Next! Link to comment Share on other sites More sharing options...
bob b Posted March 28, 2012 Author Share Posted March 28, 2012 I'm wondering whether something like Araldite is electrically conductive?I could solder on another connector and then 'glue' it on top of the screw head. Clever or what! Link to comment Share on other sites More sharing options...
Robinhood Posted March 28, 2012 Share Posted March 28, 2012 ....you can get electrically conductive (silver-embedded) epoxy glue, which would possibly suffice. A reasonable source used to be Maplin, but I can't find it on their site. RS components do still do it, but I think the price would be prohibitive. Might be worth a Google, I'll have a further look around and come back if I spot anything. Edit: ....had an amble round the web, but can't find anything much below £40 (at RS Components and CPC) :-( Link to comment Share on other sites More sharing options...
Guest Tracker Posted March 28, 2012 Share Posted March 28, 2012 If there is enough room to get a screwdriver onto the screw can you undo it slightly whilst using a flat blade driver between the washer and the tank to maintain pressure and hopefully hold whatever is inside in place and then insert the end of the cable between washer and tank and retighten? Smear it with vaseline or grease and cover it with a piece of gaffer tape to keep it dry? A lovely bodge and one that I would be proud of! Link to comment Share on other sites More sharing options...
bob b Posted March 28, 2012 Author Share Posted March 28, 2012 Cheers Robin. There's a Maplin in Brighton, which is not far from me. I'll ring them and try the fix tomorrow. I tried that Tracker and although it moves, it feels as though there's a nut inside the tank. I'm reluctant to push my luck with that dodge in case I can't tighten it up again and the tank dribbles. Link to comment Share on other sites More sharing options...
mark hinde Posted March 28, 2012 Share Posted March 28, 2012 Are you sure there is a nut on the inside as if its in the tank, how did they get the nut on in the first place. I would have thought the screw threads into a captive thread on the sensor inside the tank, but I may be wrong. Link to comment Share on other sites More sharing options...
Robinhood Posted March 28, 2012 Share Posted March 28, 2012 ....I suspect the Maplin supply may have "dried up" - I can see other people referrring to it historically, but as my post above now says, I can only find a two-part kit of conductive epoxy elsewhere at around the £40 mark. I think I would be inclined to use a cheap bit of epoxy putty; butt the existing "tail" up hard against the screw head; and then pack over the top with putty. (it isn't conductive, but as it is easy to work, sticks well and doesn't drip/run, you may get it to hold together, and retain the connection) Something like: http://www.maplin.co.uk/epoxy-putty-stick-43442 Link to comment Share on other sites More sharing options...
bob b Posted March 28, 2012 Author Share Posted March 28, 2012 Thats not a bad idea actually. I can solder a new connector on the end of the cable and I've got some 90 second araldite which I can dollop on top of the connection. If it doesn't work I've lost nothing and will take the tank down.I suspect that there is a nut inside the tank Mark by the way the screw turned....if that makes sense. Link to comment Share on other sites More sharing options...
bob b Posted March 28, 2012 Author Share Posted March 28, 2012 You can all 'stand down' now. Robin's idea worked a treat. I'll smear some waxoyl over the repair tomorrow to keep the weather out. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted March 28, 2012 Share Posted March 28, 2012 mark hinde - 2012-03-28 4:53 PM Are you sure there is a nut on the inside as if its in the tank, how did they get the nut on in the first place. I would have thought the screw threads into a captive thread on the sensor inside the tank, but I may be wrong. I was under the impression (quite possibly wrongly!) that this level-sensing arrangement was simply based on screws driven through the wall of the tank. Basically, that the fixings in the photos are not bolts (with a nut on the inside of the tank) but just common-or-garden self-tapping screws. Probably doesn't matter much now a workaround has been found, but might be significant if the problem occurs again. As Mark asks - "If bolts/nuts were used, how would the nuts be put on the bolts?" Link to comment Share on other sites More sharing options...
bob b Posted March 28, 2012 Author Share Posted March 28, 2012 There is a large access (threaded?) cap in the bottom of the tank Derek. I assume that if I could raise the motorhome high enough, I could get my arm through and get access to the nut. It would be a hell of a job though.The araldite has gone off now and the fix seems very secure. Although the nut and bolt are stainless steel, the connection is copper. This is what set off the corrosion which ended in the breakage. Link to comment Share on other sites More sharing options...
Robinhood Posted March 28, 2012 Share Posted March 28, 2012 Derek Uzzell - 2012-03-28 6:47 PM As Mark asks - "If bolts/nuts were used, how would the nuts be put on the bolts?" ....in exactly the same way as the nut on "nut in" pipes for waste feeds would be. Secured through an access hatch (presumably in this case assumed to be on the top of the tank, as it isn't visible- edit: in light of Bob's parallel post - it probably is visible :-) ) before the tank is mounted. Easy enough for installing a level-sensor, especially if it was pre-wired with a connector to the main loom on the remote end. Now, I'm also certainly not sure that it is a nut-fitting either, but as Bob says, once you find out it is it's then time to drop the tank. (I have had to drop the tank on an Autosleeper before now, to access the nut in exactly the manner described above). Hope it stays secure! Link to comment Share on other sites More sharing options...
bob b Posted March 28, 2012 Author Share Posted March 28, 2012 Dave Newell would be proud of my bodge! Link to comment Share on other sites More sharing options...
flicka Posted March 28, 2012 Share Posted March 28, 2012 I'm a bit late seeing this Bob but if you have any future problems this type of terminal may be able to slide under the screw head http://uk.rs-online.com/web/p/insulated-crimp-terminals/1611819/ Link to comment Share on other sites More sharing options...
Derek Uzzell Posted March 29, 2012 Share Posted March 29, 2012 There's an example of waste-water-tank level-sensing studs ("Waste Water Tank Couple Screws" - £3.99) towards the bottom of the following webpage: http://www.rainbowconversions.co.uk/Equipment/Electrical/electrical.htm This product looks like it can be fitted from outside the tank, with sealing using the Rawl Nut principle: http://www.fastfixdirect.co.uk/code/rawl_nut_information.asp I note that, when this type of stud/screw sensing arrangement is used on Swift motorhome waste-water tanks, there is advice in the owners' handbook that - if the full-tank warning fails to function - the sensor studs/screws should be removed and cleaned. This suggests that removing the studs is quite straightforward. Logically, it should be significantly easier for a motorhome converter to fit these studs from outside the tank rather than mess about threading nuts on to bolts via an inspection hatch. In fact, I can't really see why there should be a need for anything other than a pair of stainless-steel self-tapping screws sealed beneath their heads with a dab of silicone. I'm not saying that Rapido hasn't fitted bolts and nuts, just that it would be a perverse approach to what is basically a simple task. Regarding Bob's plan to use Waxoyl to protect the repaired connection from the weather - I believe it would be preferable to 'encapsulate' both of the studs' heads with a large blob of silicone sealant. This would not only provide weather protection, but further strengthen the connection between cable and stud. If the problem persists, then it might be sensible to drill holes in the tank at the same height but an inch or so away from the positions of the original studs and use the "Waste Water Tank Couple Screws" shown above instead. Link to comment Share on other sites More sharing options...
bob b Posted March 29, 2012 Author Share Posted March 29, 2012 I've saved that link to my Favourites Derek. I'm going to fill the waste tank tomorrow and test the repair. If the fix has failed I may well purchase those items you've highlighted.My only problem is that I've got no idea of whats attached to the screws/bolts inside the tank. Is it a float assembly? Link to comment Share on other sites More sharing options...
Robinhood Posted March 30, 2012 Share Posted March 30, 2012 ..........If the original is as per Derek's example, there is nothing fixed to the screws, the signal simply relying on continuity between the two screws being provided by the level of water in the waste tank rising to contact both of the inner ends of the screws, allowing a current to flow. A clue as to whether they are indeed similar is thus the question of whether your gauge currently gives a variable waste-water level indication (as is common with fresh water systems that generally use more sophisticated probes), or simply, (as is also common for waste readings), a singe "full" or "nearly full" warning. If the latter, I would suggest there is a high probability that your current system is like Derek's example. edit: typo Link to comment Share on other sites More sharing options...
bob b Posted March 30, 2012 Author Share Posted March 30, 2012 My system brings up a light on the control panel telling me that the waste tank is nearly full. There is no level indication. So the items that Derek high-lighted would fit the bill a treat. Many thanks to all for your help. Link to comment Share on other sites More sharing options...
Guest pelmetman Posted March 30, 2012 Share Posted March 30, 2012 So this gauge tell's you when the waste tank is full..................Mine overflows when its full :D.......... I guess that's the trouble with us older ones we start to dribble :$ Link to comment Share on other sites More sharing options...
Derek Uzzell Posted March 30, 2012 Share Posted March 30, 2012 There are (at least) three types of waste-tank level-sensing systems: 1. A ‘probe unit’ that is fitted in the top surface of the tank and can provide graduated readouts as the tank fills up. This is the same sort of unit used for providing water-contents information for many motorhome fresh-water tanks. As the probes can need occasional cleaning, it would be a cruel motorhome manufacturer who fitted such a unit into a waste-tank if removal of the probe-unit would also require the waste-tank to be removed. 2. A ‘float-switch’ fitted through the wall of the tank at a suitable height. When the waste-water in the tank lifts the switch’s float, this causes a light to illuminate on the motorhome’s control-panel warning that the tank is approaching full. The UK company ‘"Zig" used to be a main supplier of these switches to UK motorhome manufacturers. They can either be installed from inside the tank or from the outside, depending on the switch’s design. An example is shown here: http://tinyurl.com/c78t4mo 3. A pair of ‘studs’ that are fitted through the wall of the tank one above the other at a suitable height. When the waste-water in the tank covers both studs, this causes a light to illuminate on the motorhome’s control-panel warning that the tank is approaching full. Link to comment Share on other sites More sharing options...
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