Safety Note
If you don’t know how old your fuel lines are or have just bought a camper, check them Now!
If you are not confident in checking or replacing them yourself please don’t hesitate in contacting me for advice on what to look for or my fuel hose replacement service.
Recently there have been a number of horror stories and videos online of campers having engine fires and sadly being a total loss. It sucks and I cant even imagine how I would feel if it happened to my pride and joy. I also have lost count of the number of engine bay fire extinguisher posts I have seen steadily increasing over the last 4/5 years. Although I think they are a great idea and run one myself I personally believe prevention is better than cure.
I do not claim to be a fire or fuel expert or claim to know the exact cause of these unfortunate happenings as there are so many potential causes. I am also not starting a debate on what is right and wrong…. I do however come across issues whilst working on Aircooled VW’s that could cause these problems we keep seeing. Therefore I wanted to share my findings with you and make everyone aware about what I see as the main potential causes.
First Off – Ensure The Basics…
How long ago did you replace the fuel hose and breather pipework?
If not recently you need to do it as priority with ethanol resistant hose. Breather hoses (8 and 10mm on early bays) and filler pipes are an engine out job, but if you are unsure how old they are or smell fuel when going round corners you need to replace them.
Are you using the right size fuel hose?
5.6mm is specifically designed to fit properly on your standard 6 mm metal piping. By fitting a fuel hose slightly smaller than the pipe it needs to fit on it will be stretched allowing for a frictional gripping force and tight seal.
Are you using the correct fuel clips?
Never use standard jubilee clips as they cut in to rubber hose. For rubber 5.6mm hose use 11-13mm fuel hose clips.
Is your carb inlet barb well seated?
These can come loose so check and permanently attach them with a fuel resistant glue / sealer such as JB Weld.
Are all your electronics isolated?
Ensure all wires have the right covers, renew any bare wiring or connectors that show bare metal. This includes your ignition leads and alternator connectors as well as battery connectors. This will reduce the chance of a spark igniting fuel should you suffer a leak.
A note on fuel filters : Everyone seems to have a strong opinion on these. The fact of the matter is most air cooled vehicles left the factory with no inline filter. That’s because they have a mesh filter fitted to the outlet of the fuel tank. Its also because fuel tanks were clean and not full of rust when they were new! Personally I re-seal and restore fuel tanks on my vehicles and run with a new fuel tank mesh filter. That way there is one fuel line running from the tank to the pump without breaks. Its how VW did it so it’s good enough for me. The only change I make to this is when I run twin carbs and need a pressure regulator, I run a Malpassi regulator and filter as it traps potential water in the system which I see as a distinct benefit.
For the naysayers, the people who run filters and scream when they see plastic filters in other peoples engine bays…..well each to their own If it works for you then fine. But i’ve never seen a plastic filter explode (they get a bad rep from the dodgy batch that was out there 15 odd years ago). I have seen more leaky glass filters than plastic ones due to the rubber perishing. But like I said whatever works for you.
Ethanol in fuel (Info aimed at UK market)
There are many theories and debates raging on the % allowed in the UK, what is supplied and whether or not it affects our vehicles. It is extremely difficult to get any definitive answers but at the time of writing it appears that the current ethanol percentage in the UK is up to a potential 5% with 10% being introduced in 2017.
Why does Ethanol exist and why haven’t we heard of it?
Since 4 star was phased out and normal unleaded was phased in there has been Europe lead legislation to reduce greenhouse gas emissions. I won’t bore you with the figures but all petrol has been up to 5% ethanol for some time. The key here is (up to 5 %). Around a few percent there was not deemed as a compatibility issue for any vehicle (under normal use i.e being used every day) and therefore the fuel pumps were not marked to tell customers that the fuel may contain biofuel. However long term use and storage of non daily driver vehicles with a full 5% ethanol has been causing issues. I have seen dissolved fuel lines and gummed up tanks jets and carb bowls.
In 2013 the maximum level of ethanol allowed in petrol increased from 5 % to 10%, however there has not been an official move for anyone to supply it. There is a directive for E10 (10% ethanol) fuels to be rolled out by 2020, however at present the most up to date information states it will be roled out in 2017. It is apparent that the full 5% is in supermarket fuels, hence its cheaper.
This may cause the following problems :
Corrosion – in long term storage, fuel containing Ethanol can become acidic and cause corrosion of aluminium, zinc and galvanised materials, brass, copper and lead/tin coated steels.
Material compatibility – Ethanol’s high solvency can cause problems with many seal and gasket materials used in fuel systems as well as with fibre glass resins. Besides a risk of fuel leaks, rubber components and resins can become partially dissolved, producing deposits that could foul carburetor jets. Replacement components made with Ethanol-compatible materials are available.
Combustion – Ethanol’s higher volatility can contribute to ‘vapour lock’ issues in older vehicles when operating temperatures are higher. Ethanol can also affect cold start performance.
Absorbs water from the atmosphere – The water sits on the bottom of the fuel tank beneath the fuel and causes corrosion and running issues. It will also cause any aftermarket plastic filters to swell (they are designed to do this) and stop the flow of fuel.
What could this mean for our air-cooled vehicles?
- Carburation problems, air leaks, fuel leaks and gummed up jets.
- Cutting out, rough running, not running at all.
- Water in fuel, blocked fuel filters, gummed up and damaged internal fuel hoses.
- Fuel leaks
Because info online and from fuel companies seen to be rather vague in my mind the potential negative affects can not be ignored. I would like to repeat that I am not saying its causing all the engine fires we see but if there is chance it could be, isn’t it worth taking action to prevent it?
What can you do to avoid potential problems ?
- First off replace your fuel lines, breather hoses and rubber seals with ethanol resistant equivalents such as Cohline, there are multiple specifications designed to withstand 10-100% ethanol and biofbio mix dependant on the grade you buy. The main areas affected are where the ethanol is in constant contact with the rubber (when campers are stored or not used every day) allowing it to be eaten away.
- Try to avoid E5 rated fuel, this many not be easy but by purchasing from the bigger names and running the higher quality fuels you are less like to get a full 5%. Never use E10 rated fuel. (It’s also a false economy to buy cheaper fuel that contains more ethanol as it will provide less MPG .Therefore the more expensive and purer fuel will take you further…..but that’s a whole other topic).
- If your vehicle is not a daily driver and is stored for weeks and months at a time this can cause some pretty bad issues. Run the engine regularly even if not moving the vehicle. Use a stabiliser in your fuel or drain it completely if being stored over winter.
What else can you do?
Check your fuel lines regularly and never ignore an unusual smell of fuel. Even without the ethanol issue fuel lines, breather hoses, filler hoses and filler cap gaskets can leak or can become porous.
Always carry a fire extinguisher ( I carry two), consider a engine bay based system such as Firetec or Aircooled Works and fuel cutoff solenoid.
I would never advise on fitting a Blazecut due to the unethical way the company operates.
If you are unsure on how to check or replace your fuel lines get an air-cooled specialist to inspect them for you.
Further Reading :
http://www.volksbolts.com/faq/fuelhose.htm
https://www.theaa.com/driving-advice/fuels-environment/biofuels