Hi guys
Just a quick question for you wise people out there, had my diesel tank syphoned over the weekend looking at fitting an anti syphoning device are they any good? worried about screwdriver in tank or worse damage if they really want the diesel they will try get it whatever the damage they cause, so not sure what to do for the best .any advice would be welcomed .cheers
wire it up to a 440v transformer when parked up for the weekend, it wont kill them but it will make them feel alive and tingly for a few hours! serve the ■■■■■■■■ right as well!
at work we have been told not to lock the caps if were leaving the wagon unattended as they just smash them off anyway and cost the company more dosh than just a tank of diesel. like you said they will get it if determined enough!
I know how you feel mate. We had both our trucks syphoned late at night last week at the farm where we park.
Luckily we leave them pretty low just in case but we still lost about £150 worth of fuel.
The farmer came off worse as he had his holding tank emptied with around £800/£900 quids worth in.
We have invested in locking caps for the tanks but wonder if thats wise. If they really want it they will just pincture the tanks - or take the whole tank as is which has been done before I hear.
We do have a plan about putting a piece of pipe down the inlet hole in the tank which will hold around a gallon of fuel so that if they try to syphon thats all they will get.
Got to work out the maths on getting it right but when we do I will let you know.
What you need is Aqueous Ammonium Nitrate in the ‘dummy’ tank, and whatch the ■■■■■■ have a jolly good barbie 
This link here could be useful, you have to give some etails for pdf downloads, the “Fuel Alert” looks like a must have gadget.
Interesting link thanks for that. We asre trying to come up with a device that the thieves can still drop the pipe down the tank and syphon out around a gallon then nothing more. Then, thinking the tank is empty will go away.
Well thats the plan 
We just have to divise it properly
I personally dont like having locking petrol caps on the tanks as I worry that they will only puncture the tanks which will be even more flaming espensive, not to mention loss of earnings while getting trucks fixed. same with anti syphoning devises if they realise there is one fitted.
Personally I think a big dog and a gun would be nice
The only way I can think of doing that would drain the top 2" of the tank, assuming the tank is full. But you’d have to hold the nozzle whilst refuelling…hang on just had a thought back soon…
I was thinking along the lines of a series Landrover telescopic filler neck, it could be easily adapted, but the inherent problem with any restrictive device is the ■■■■■ will undoubtedley know that the device is there as soon as he puts the hose in,even if the device goes to the bottom of the tank, and will bypass it and go for the sender/filter or just stab the tank 
i dont think there is any foolproof way of stopping it completely if they cant go in the top they will just go under or take the sender unit out. like others i leave mine unlocked so i dont get the extra damage and huge repair bills
Thanks for the replies but as i suspected were all in the same boat all i can do is leave it as empty as poss and unlock the cap when i leave it overnight that will save me 25 quid for a new cap at least.Thanks again
Wonder if/when manufacturers will be offering “armoured” tanks?
TC
The_Catman:
Wonder if/when manufacturers will be offering “armoured” tanks?TC
the army already do them but its a bit extreme to spend quite a few million quid just to protect some diesel! 
Silver Surfer,
I looked into these devices and to be honest they are really there to protect the firm against drivers/staff stealing a bit for their car not ■■■■■■ etc. who will puncture the tank.
Always thought myself after being cleared out twice last year in the yard about fixing a steel box around the tank with a padlocked flap in the top for filling (box in the padlock so chisels/bolt cutters can’t get access. The box would need to be bolted to the chassis with non standard bolts (like locking wheel nuts) so it can be removed for inspections.
Should be fairly cheap to manufacture( much cheaper than the 2 grand I lost last year) and would put the scum off tackling your unit when many easier victims are at hand.
We could call it the Fuel Safe - blimey anyone fancy going to business it sounds like a plan!! 
Another option is a second or third tank located under the fifth wheel or high in the chassis (rigids) and change the sender configuration so that the hidden tank becomes the main. ( Yes the belly tank ) The other tanks can be left next to empty. Put a steel plate under the tank so if the smart arses do find it they can’t puncture it anyway.
Third option would be a plastic inner tank coupled to and anti syphoning device, if the tank is punctured only a couple of gallons is lost that is held between the outter and inner tanks. The chisel/screwdriver used to puncture the outter tanks would simply bush the inner plastic tank inwards without puncturing it. ■■■■■ leaves gutted that the tanks where empty and a simple repair at a convenient date is all that needs to be performed.
Exposed fuel lines could be easily armoured to stop cutting with knives etc.
I really must get out more!! 
If they are going for your fuel, they will
persevere until they have hit, better to
lose the fuel than to have a costly bill
for the repair of the tank and also the costs
of the cleaning bill for the fuel spilt on the ground
as your tank was leaking due to the hole in the bottom,
Best thing is to leave enough for the first part of the day then fill up dont leave it full over the weekend and leave a note stating that on the tank
Mind that might P155 them off even more
The best way to prevent it really is to move to a more secure operating centre if your vehicles are being targeted when you park up unattended.
Silver cheq plate cut into parts to fit around the tank and welded around the tank, nice and strong cant stick out through that and and not a to expensive job…
Why not pay the local nutter to protect your yard for a couple of weeks. once he’s caught them you could feed them to the pigs. Job done.
I have both anti syphon and a locking fuel cap and I see it like this.
I park in a yard with other trucks. If I were a thief I would go for the easiest target. Why bother trying to defeat security when there are easier trucks to steel from?
My truck is not impregnable but it is harder to get diesel out of than the others. Mine has never been syphoned, others in the yard have.
If it stood on its own then maybe it would be a different tale.
Selfish I know but its dog eat dog.
Carl
It’s sad to say that locking caps just push them to damaging the tanks or lines & we can’t always park in a secure compound. If I knew I was going to park where it was not safe I used to leave one tank almost dry & park the other side against a wall & dump all the air out of the tractor & trailer suspensions. The tea leaves then went underneath & ripped out the fuel lines at 2 seperate parkings.