Emergency fuel tank

[Stemar]

So do I! BUT, gravity fed are the key words, with all those joints.

You've got to get 'em right, but with all new stuff, it isn't that hard. IIRC, most of the joints have olives, so the trick is not to overtighten them. They'll likely leak a bit, so you then trek 'em up until they stop leaking, but no more. Overtighten, and you throw away pipe and olive, and start again.

If you're really serious about not having leaks, but don't have confidence in your ability, a bit of Loctite 577 may help you sleep at night

 

[TernVI]

I went to my local car breaker and got a matching pair of filter bodies, Volvo/Renault, but only because they were the tidiest pair I saw. I got four taps and a bit of copper pipe from ASAP and set them up in parallel, with a tap upstream and downstream of each. I was going to use two T taps, but it worked out a lot cheaper to use four on/off jobs. It was a few years ago now, but the whole job cost me change from £50. My fuel is gravity fed, but if the fuel had to be sucked through the filters, I'd fit a bulb pump. With that, I reckon you'd be able to change a filter with the engine running.

You should not use copper or brass in contact with diesel.

 

[Gixer]

You should not use copper or brass in contact with diesel.

I’ve just been told this, apparently the additives in modern diesel will damage the pipes eventually. The current thinking is A1 rubber pipes For diesel lines, does this sound correct?

 

[fisherman]

I’ve just been told this, apparently the additives in modern diesel will damage the pipes eventually. The current thinking is A1 rubber pipes For diesel lines, does this sound correct?

Rightly or not I always used hydraulic pipe: the engineer who recommended it put copper and hydraulic pipes under a blowtorch to show the hydraulic was more fire proof, when I expressed doubt. You get good seals with no washers involved. (excepting the nipple dowty seals)

 

[Gixer]

Will this filter will be ok for the 1gm?
Racor 120AP Diesel Spin-On Fuel Filter (30 Micron / Clear Bowl)
anything that gets past the 30 micron will get picked up by the engine filter right?

I’m going to Southampton via Portsmouth (A27) tomorrow, anywhere along that way I could pick one up?

 

[Mister E]

For the problem of the tank being below the engine, how about a 12volt electric pump at the tank.
If you are really lucky you will get a fuel leak where the air is getting in.

 

[Mister E]

Just had a thought, have you checked that the fuel tank air vent is working properly?

 

[Gixer]

Thanks Mister E,
I've never needed a pump before but do have the thought of adding one in the back of my mind. I’m just conscious of complicating the system.
I had the system checked by a professional and he was stumped, as it’s 30 years old I’m going to pull the lot out, tank and all and start again.

 

[fisherman]

On the Lord Nelson second engineer was having trouble with one of the gennies, Perkins 6354, and for some reason asked me to look. I asked how many joints in the fuel line that could leak; nine, I think, was the answer, so there you are pronounced I and went back to my Guinness. When the chief turned up that's what they found.
When I fitted a new engine, same as the old one, first day we had trouble and went back in. The fuel system, fine for an old tired lift pump was leaking air through one of many old fittings, so changed the pipework which I found had been repaired with several odd pieces .
Perhaps before tearing everything out you could try a) a temporary service tank, ie outboard tank, on gravity, then b) new pipes and joints.

 

[Stemar]

I’ve just been told this, apparently the additives in modern diesel will damage the pipes eventually. The current thinking is A1 rubber pipes For diesel lines, does this sound correct?

Interesting. At the time I did it, IIRC, the Boat Safety Scheme for canals insisted on rigid pipe, and I suspect a lot of boats used copper. 15 years on, my system is still going strong, but I will keep an eye on it. What should I be looking out for? Leaks, or will it just disintegrate and dump a tankful of diesel in the bilges?

 

[TernVI]

Interesting. At the time I did it, IIRC, the Boat Safety Scheme for canals insisted on rigid pipe, and I suspect a lot of boats used copper. 15 years on, my system is still going strong, but I will keep an eye on it. What should I be looking out for? Leaks, or will it just disintegrate and dump a tankful of diesel in the bilges?

The copper may cause the fuel to breakdown, depositing tar-like asphaltene compounds throughout the system.

 

[TernVI]

I’ve just been told this, apparently the additives in modern diesel will damage the pipes eventually. The current thinking is A1 rubber pipes For diesel lines, does this sound correct?

My feeling is that fuel hoses have a limited life.
I've just replaced the petrol hoses on my bike, again, at (about) 12 years old they are not as supple as they were.
I don't know about 'A1', seems to be a 'marine' rating, I would look to get something that met SAE J30 R6 as well, or do some asking of the right people to understand the ratings. Forlong runs I might consider rigid stainless or other metal pipe with the correct plating.
Any hose which is immersed needs to be a different rating, with the outer cover 'NBR' or something, 'in-tank' hose is a bit dearer.

When I've had aggro with things like this, I've found it good to get to fundamentals. If something is supposed to hold suction, apply some suction to it and check it holds. If a system is supposed to be delivering fuel at a pressure to the injector pump, tee in a gauge or manometer and have it show you some pressure.
Obviously adding test points adds more joints to leak, but it's all good practice.
If you suspect there is air in the fuel, temporarily plumb in a clear filter which will trap the air and show it to you.
You just have to beat it with logic.

 

[fisherman]

Another cure I saw but might not recommmend, a half inch steel pipe from the tank to near the lift pump, normal sized flexi for the last foot or so. Sheer volume in the pipe helps with bleeding and air not getting caught.

 

[TernVI]

Another cure I saw but might not recommmend, a half inch steel pipe from the tank to near the lift pump, normal sized flexi for the last foot or so. Sheer volume in the pipe helps with bleeding and air not getting caught.

Not sure about that?
I get the impression my Yanmars would cope with a small air bubble (miss a beat and carry on without stopping), too big an air bubble and it's all over?
Could it be like brakes, narrow pipes, easier to bleed?

Obviously at high flow rates, narrow pipes mean more pressure drop, more suction, any air leaks made worse, but 1GMs don't really know about high flow rates!

 

[Gixer]

I really appreciate the effort you guys are putting into this thread.

I think I’ve found a Tek-Tank that will fit in the lazerette, only thing is it’s 18L as apposed to the 25L one I have at the moment. As I sail on the south coast of the UK diesel is pretty easy to come by so I can’t see that being a problem...

 

[Tom Bowling]

I recently had a frustrating air in the fuel system problem which caused the engine to stop at the worst possible times.
The problem only occurred after a long running period, so the air ingress was small.
It still had the same effect though, unexpected engine stoppage.
The was problem was found in the return pipe from the secondary fuel filter on the engine side.
This pipe is fed from the top of the filter via a banjo fitting with a 0.5mm orifice, it’s purpose being to bleed fuel and any accumulated air back to the tanks.
I had been using this banjo fitting to bleed the filter housing and could see that the orifice was not blocked.
This where Murphy’s law came into play.
The 3mm i.d. pipe after the orifice was completely blocked with a hard unidentifiable substance that had to be drilled out after cutting the pipe in half to get access.
This was then brazed back together and refitted.
By divine intervention, l have had no further problems, touch wood.

 

[JimC]

Just asking: if a lift pump fails does it normally fail open or shut i.e. would it still pass fuel from a tank that was mounted at a higher level?

 

[fisherman]

If diaphragm, it has in and out valves on one side of it, so fuel could gravitate through. The worst failure is a leaky diaphragm that allows fuel to flow into the sump, in a Ford at least.

 

[penberth3]

If diaphragm, it has in and out valves on one side of it, so fuel could gravitate through. The worst failure is a leaky diaphragm that allows fuel to flow into the sump, in a Ford at least.

Not sure what head is needed for gravity flow through the in/out valves? I suspect it wouldn't work. I know what you mean about diesel in the sump!

 

[Gixer]

So, just to update you guys. I’ve put in a new tank, all new fuel lines and even new fuel. I’ve still got a problem and turns out it’s my lift pump.
It could well have been this all along but I’m trying not to think about that….