Leaking Heater Fuel pickup, anyone used a Wema inspection hatch to repair

davidwf

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Got a leak from the fuel standpipe fitted to a plastic tank in Beneteau, yes I agree daft place to fit it and I should have known better and taken it from the filter. But thats water under the bridge.

Now I need to fix it, looking at a previous thread a Wema inspection hatch was suggested apart from the fact I have to make a bigger hole, has anyone used one of these in a plastic tank, Tek Tanks sell them and have a good video as to how to fit them http://youtu.be/zFqfW4-gKPg .

It looks good and I have emailed Tek Tanks to ask if it will withstand some positive head as where it will be fitted is about an inch below the top of the tank.
 

David2452

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Not so much fitted one as used one that was already there to make fitting the standpipe easier and removing the risk of swarf in the tank, have had not call back on it so I would do it again. You do the right thing using a standpipe, the pumps do not like drawing off of a wide bore tube, they will do it to a degree but do not work anything like as reliably as when drawing up the 2 to 3 mm bore of a standpipe.
 

davidwf

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Bad news not enough room to fit a Wema hatch so will have to have a plate made. Also got to drain at least 30 to 40 lt of fuel out in order to work on this. Picture below shows offending take off.

Had to tighten it so much the washer has cut the rubber. Now got a very slight seepage which I am using a absobant mat to soak up.
 
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pvb

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Bad news not enough room to fit a Wema hatch so will have to have a plate made. Also got to drain at least 30 to 40 lt of fuel out in order to work on this. Picture below shows offending take off.

Had to tighten it so much the washer has cut the rubber. Now got a very slight seepage which I am using a absobant mat to soak up.

Can't you refit with new rubber seals? And perhaps rounding off the edges of the washers?
 

davidwf

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Can't you refit with new rubber seals? And perhaps rounding off the edges of the washers?

Yes I could refit it but not happy that it failed in the first place so no real guarantee that if I just replace the washer it will cure it. Bear in mind its only 18 months old. Plus draining the tank is the big undertaking given that it's fully topped off. I reckon I will have to get at least 30 or 40l out to drop the level sufficently to work on this.

The washer only cut the rubber because it had to be exessively tightend to stop the leak, I had abut 2l trapped just in front of the tank in just over a day. Luckily there was a great heating guy in the marina that came over and sucked it out with a Pela.

Think best bet is to get some fuel out of the tank and then have a good look at the problem.
 

davidwf

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You could look at one of these (bottom of page)
http://www.furneauxriddall.com/acatalog/Wema_Fuel_Water_Senders.html
They are a lot smaller than an inspection hatch and also have support from inside the tank, then you have an 1-1/4” bsp plug that you can fix the standpipe to and just screw it in.

Yes that looks the business, I like the look of the HFL one as its got split ring for the underside. Will get one on order now.

Is there a particular sealnnt thats best to use with the 1-1/4 bsp plug?
 

David2452

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No special one, just a good quality medium density one, obviously diesel resistant, roughen the Poly tank up a bit and alcohol wipe where the gasket sits. Probably worth a mention that if you thread string through two of the holes at 180 deg in the horseshoe and then from underside the tank through the corresponding holes in the gasket and flange it makes it a lot less stressful. Actually on a poly tank the internal horseshoe is probably essential to get a good seal.
 

Heckler

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Bad news not enough room to fit a Wema hatch so will have to have a plate made. Also got to drain at least 30 to 40 lt of fuel out in order to work on this. Picture below shows offending take off.

Had to tighten it so much the washer has cut the rubber. Now got a very slight seepage which I am using a absobant mat to soak up.
I fitted one like that to my 351, i removed the level float mechanism and got my fingers inside to hold the pipe whilst i tightened the nut.
Stu
 

davidwf

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Well I fitted a Weema Flange with a 1 1/4 BST plug with the pipe welded to it as the new pickup, all went well until I put the fuel back in :-(

To cut a long story short I now have a leak through 6 screw holes it's because I had to tighten the flange so much to accomodate the slight curve on the tank it forced the seal out around the screw holes. Curve is very slight and I hadn't noticed it before. So had to pump out the 70lt of fuel I had just put in, not one of my better days,

Two options now , replace the tank which actually is not that expensive but a pain because I will have to drain yet more diesel and get the tank out, which looks doable or try to find a plastic tank repair guy, found a company at Derham and will call them Monday to see if they will come out to do a repair. Not inclined to take tank to them as if its out a new one is going in, not draining the fuel out again.
 

exfinnsailor

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I looked at that on our Beneteau 323. The tank has about 50mm above and other options included going in the side or the safe route from the filter. After careful thought and reading posts about not using the filter outlet I decided not to drill the tank. I hope you manage to sort out the tank in situ. Our Mikuni heater works very well even though it is connected to the filter :)
 

davidwf

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Update on Tank

Have had the tank repaired by Stansa plastics in Suffolk, using plastic welding gear, hopefully will have done the job. Will only really know once the tank is refilled.

Certainly a lot easier than removing the tank. I will now take fuel from the filter for the heater.
 
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exfinnsailor

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Looks like a good job :) now all you have to do is connect up to the fuel filter and away you go. Don't know why they insist you have a separate supply from the tank. I was told that you leave the standpipe short so you always have enough diesel for the engine but we carry an extra couple of cans anyway. Then I was told you could get air coming back from the heater into the filter :eek: Not had that. Only problem we did have was priming the heater the first time. Very long run to the heater and the heater tripped out because on no fuel. I had to suck the fuel up the pipe got to about 10mm from the end and then pushed the pipe back on the heater. Next time I fired the heater up it pumped the fuel through the last 10mm of pipe.
 

davidwf

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I used a small syringe to initially prime the fuel line when I first installed the heater, hopefully won't have to do that this time as there is still fuel in the pipe.

I am fitting this to the CAV filter got it from ASAP, but first I will get engine running then when that is ok introduce the change with the fitting for the heater.
 
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David2452

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Looks like a good job :) now all you have to do is connect up to the fuel filter and away you go. Don't know why they insist you have a separate supply from the tank. I was told that you leave the standpipe short so you always have enough diesel for the engine but we carry an extra couple of cans anyway. Then I was told you could get air coming back from the heater into the filter :eek: Not had that. Only problem we did have was priming the heater the first time. Very long run to the heater and the heater tripped out because on no fuel. I had to suck the fuel up the pipe got to about 10mm from the end and then pushed the pipe back on the heater. Next time I fired the heater up it pumped the fuel through the last 10mm of pipe.

Nice job David, but you could have had them weld in a threaded boss whilst they were doing that.
The reason for using the standpipe is that the pump has a much easier life if it is used; the stand pipe is very small bore like the rest of the pipe. In some instances (often distance dependant) with larger bore pipe, like the engine pick up to the filter, the pump finds it impossible to draw and the heater simply will not work, in others the fuel can drain back more easily and you get a no start for a few attempts then it will fire up, effectively it is having to "prime" at each start. As an analogy, suck up some milk (other beverages are available) through a straw, now try it through a 22mm copper pipe. The solenoid dosing pumps are not good at "sucking" hence the requirement to fit it close to the fuel supply. The specification for these heater installs are designed to give the thing the best chance of working consistently and to ensure maximum life from the components. Yes, they do (more often than not) work if not installed precisely to the specs but that means they are operating outside of their design parameters. On a self install this may not be such an issue as you can fiddle to your heart's content when (if) it goes wrong but my installs are always to spec, if only so I get paid warranty for any issues instead of it costing me directly as I then am assured any fault wil be a component rather than the install.
 
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davidwf

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Totally accept that best method is to keep fuel pickup separate from the engine fuel feed. However as the only surface that can accept a pickup on the tank is below the level of the full tank I have to be certain it cannot leak. So far have tried two methods both failed. Now that might be my incompetance or due to the fact the the surface where the pickup will have to go is below the fuel level with a full tank.

So I admit defeat and I will take it from the main fuel filter, its that or go to the expense and hassel of fitting a small dedicated tank for the heater. I have had a boat in the past where the feed was from the filter and that worked fine so I will go that route and if I have problems fitting a steel blanking plug into the filter housing will be a lot easier than fixing the tank again.

Worth noting that Polyetheline is a terrible substance to weld it is very waxy when melted hence difficult to smooth out as it sticks to the tool. I was luckty to find a chap who was willing to undertake this work.
 
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