Online School With JBugs

The battery sits in a tray under the rear seat in all Beetle models. The problem is that the rear seat springs are made of steel and the original padding was made of a treated coconut fiber commonly referred to as “horse hair”. Well, the horse hair and seat upholstery are flammable, so it is possible for them to catch fire.

If enough force (such an adult sitting down) is applied to the seat, the springs can depress and contact the terminals on the battery. If that happens, it’s possible for the seat springs to arc on the battery and catch the horse hair on fire.

It’s fairly uncommon for it to burn down the whole car, but it can result in the occupant of the seat getting a quick shock or perhaps even burned.

To avoid arcing, all you need to do is place some type of non-conductive insulating material on top of the battery and you should be fine. If you smell or see smoke inside the cabin while working on or driving the car, under the rear seat would be one of the first places to check.

Adding some positive terminal cover and negative terminal cover pretty much eliminates the issue, but I always lay an insulating mat over anyway in case they crack.

I mention this area because VWs are known to have incredibly simple electrical systems. The problem is that the cars changes hands quite a bit and it can be hard to track down someone else’s shoddy wiring when the electrical system is working as it should.

Just because everything works, doesn’t mean you shouldn’t check to make sure you don’t have any loose wires hanging around behind the dash. Almost every single project car I’ve ever encountered had at least one exposed wiring contacting the inside of the body when the new owner first picked it up.

The Beetle gas tank is located in the trunk area right next to all that wiring. German engineering is fantastic, but safety features were lacking when the car was originally designed. The Beetle gas tank has a seal on the top between the flange of the sending unit and the gas tank. It prevents gas from leaking out of the top of tank as it gets sloshed around when driving.

It is very common for the sending unit seal to be worn out enough to allow gas fumes into the cabin, if not allow liquid gas to spill out of the tank (like on my own car). Exposed electrical and gasoline make for a dangerous combination, so always make sure you cover any exposed wires and replace your sending unit seal every couple of years.

This one is fairly simple, but is one of the most common causes of an engine fire in Beetles (and buses with an upright engine).

DO NOT EVER INSTALL A FUEL FILTER IN THE ENGINE BAY!!!

It seems pretty straight forward, yet happens all the time. People install it in the engine bay because it is the most easily accessible location to replace it as needed. I’m here to tell you, TAKE THE EXTRA STEP!!!

Installing the fuel filter in the engine bay adds two more connection points where fuel can leak out onto a hot surface and ignite. All you have to do is relocate the fuel filter to the other side of the fire wall above the transaxle. THAT’S IT!

In short, the additional weight of the fuel filter commonly causes the pressed-in fitting on the carburetor bowl of stock carburetors to wiggle itself out and spray gas all of the engine bay. Most aftermarket and reproduction carburetors use a threaded fuel fitting, so it’s not as much of a concern these days.

However, that doesn’t change the fact that you now have two new points that can leak and cause a fire. Move the filter.

Along those same lines, the fuel hose we use on our old carbureted VWs does not stand up well to the ethanol blend gasoline found in the United States these days. We recommend replacing all fuel hoses at least once a year to prevent leaks.

You may not be able to see it under the braided fabric on the outside, but every time the hose bends, the rubber cracks a little bit. The ethanol fuel blend contributes to making it brittle and easier to crack. Fuel hose isn’t expensive, and in the end it’s worth it to replace the hose for peace of mind, if nothing else.

Remember to always check your hose clamps when you install new hoses to make sure they are secure. Vibration and fuel pressure can free the hose from the fitting and cause a leak, which would be very bad.

Fuel can also leak from the diaphragm in the fuel pump, so make sure to occasionally smell your dipstick when you go to check your oil level. If you smell gas, you may need to replace the fuel pump. Gas in the oil is extremely dangerous because it can reduce your engines ability to cool itself, which can lead to a total failure in time if not properly address.

NOTE: Above I mentioned that if you smell gas in the oil, it could be the pump. If the pump is not the cause, you could have cylinder blow-by, which may require you to rebuild the top end of the engine in the near future.

You should always disconnect the battery when you’re working on the electrical system of the car. Doing so minimizes the chances of damaging the car if something is wired wrong.

Likewise, disconnecting the battery takes away an ignition source that could cause a fire. There can’t be sparks from the electrical if it doesn’t have anywhere from which to draw power.

Remember, when disconnecting the battery, always disconnect the ground first, and then remove the positive cable.

One more thing to note - metal jewelry such as rings (or a watch) should be removed when working on your car. I recall a seasoned VW owner working on his car, tuning the carburetors if memory serves. His metal watch band arced out on the alternator battery post and the alternator itself. In the blink of an eye, his watch and band had burned his wrist so badly that a trip to the hospital was needed.

If you need to service any part of the car that has a fuel line running to it, start by using a set of locking pliers (like Vice Grips) to cut off the fuel supply. There are specialty clamps you can use, but they can be pricey or difficult to find. Locking pliers won’t tear apart the hose when adjusted properly, so you don’t have to worry about damaging the hose.

Once the fuel line is clamped, grab a rag and something into which you can safely pour the fuel left in the line. Disconnect the hose clamp, clean up the excess fuel, and find something to plug the line.

Once you’re sure there is no chance of a leak, relocate the closed line away from any potential ignition sources and get to work.

Without an ignition (sparks from electrical system or heat from the engine running) or fuel source, you’ve substantially lowered the risk of an accidental fire while working.

Vehicle fires are common in old VWs. Don’t contribute to the possibility by not taking care of your car. You or a loved one could get hurt - or worse, your car could get hurt! Jokes aside, take the steps to be safe and ALWAYS carry a fire extinguisher rated for automotive use. And if you can afford it, look into a fire suppression system like BlazeCut.

It’s better to have it and not need it than need it and not have it. You may not be able to prevent the cause of the fire, but you should have the tools to put it out.