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The adverse effects of water on motor vehicles

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Normal supplies of fuel from oil refineries can contain up to three percent water in solution. In wet weather this can increase due to condensation in bulk tanks. Fuel can contain up to ten percent in solution before it becomes visible as a separate solution. Whilst the droplets remain below the wavelength of light, they will not reflect light and so are not visible.      

Service station tanks also generally contain water to bring the level of the fuel close to the bottom of the pump pick-up pipe. This also allows an area where water can settle out of solution, and other foreign matter can collect. In some cases fuel must be allowed to settle for up to three weeks after being pumped from a tanker to a shore installation. The lines are often flushed with water between each different batch of leaded, unleaded petrol/gasoline, distillate etc. It should be standard practice for a service station to check the level of water in their underground tanks with a dipstick coated with a paste that is water sensitive, and pump out excess water.      

What happens when this fuel and moisture enters the fuel tank of your vehicle or machinery? Fuel tanks rust, and die-cast metals develop a white paste or powder in the presence of water. Also condensation builds up in fuel tanks when humid air replaces fuel that is consumed. Condensation also builds up in conjunction with a temperature change of 4°C or 7°F. Fuel tanks heat up from air passing over engine, transmission and differentials, or in the case of diesel or fuel injected engines from hot returned fuel.      

How do we get rid of the water that accumulates in fuel systems? An earlier practice was to add methylated spirits to emulsify the water. However this does not break down the surface tension of the water, and it also pulls more water out of the atmosphere as it is anhydrous. Obviously the best way is to add the Pro-Ma PT5 Petrol Treatment at each tank fill. This product will break down the surface tension of the water and allow it to be disposed of slowly through the exhaust system as steam.      

If you have more water than the Petrol Treatment or the diesel treatment (for Diesel engines can treat up to 8 times as much water as Fuel Treatment), then drain or pump the water and fuel out and fill with fresh fuel and Pro-Ma Petrol Treatment or Pro-Ma Diesel Treatment to remove the last vestiges of water. For motor mower and line trimmer fuel tanks, I always strain the fuel through a funnel with a 100 mesh strainer. This will not allow water through, and it is amazing how much dirt and foreign matter is collected from apparently clean fuel.      

If you have a Diesel truck or tractor, or a fuel injected car, fill the tank at the end of the day, and keep the tank as full as possible. This way there is less likelihood of picking up foreign matter from the bottom of the tank and there is less surface area for evaporation which can be as high as 10%! The upper cylinder lubricant in the Pro-Ma PT5 Petrol Treatment will help to protect the metal components from corrosion.      

Whilst we are talking about fuel injected and also unleaded vehicles, I have had a number of queries as to how you displace the spring-loaded flap in the filler neck of an unleaded fuel tank. You don’t have to. Add the correct quantity of Petrol Treatment to the filler neck when the cap is removed, then insert the petrol filler hose nozzle. This will open the flap and allow the Petrol Treatment into the tank before the fuel, and ensure thorough mixing. Any that may remain will drain through the vent hole into the tank. There is no need to use screwdrivers or any other tool to get the Pro-Ma Petrol Treatment from Pro-ma Fuel and Oil Additives into the tank.      

The most common complaint in wet conditions is that the engine won’t start! In almost every case this is due to dirt or oily residue on electrical and ignition components. We used to demonstrate that we could throw a bucket of water or turn a fire hose on a clean engine, and it would start every time. However keeping an engine clean, particularly the ignition system is the last thing people want to do.      

Consider the situation where a Distributor has been conducting a Clinic at night and it has been raining heavily. If the car won’t start or stops on the way home through water ingress, you can really put yourself at risk. Generally all that is necessary is to wipe the spark plug leads and distributor with a clean rag or with a rag dampened with household detergent every few months. Take care not to dislodge any wiring, and wipe dry. Do not use steam cleaners, or high pressure hoses on engine electrical wiring or components.      

Modern ignition systems operate on voltages up to 50,000 volts+ so they are readily susceptible to electrical tracking over dust and moisture. Do not drive through water more than 150mm (six inches) deep if you can avoid doing so, or you have a vehicle specially equipped to do so.      

Most vehicles are fitted with at least a pair of disc brakes, and a high temperature clay based or bentonite grease is specified for non-driving wheel bearings. A small quantity of water will break down clay based grease and result in premature bearing failure. When you drive a car into deep water and the gearbox and differential are at operating temperature, the sudden chilling effect can result in water being drawn in through breathers ad past seals. Water entering through an air cleaner in significant quantities can destroy an engine. If you have no option but to drive through deep water, check engine, gearbox, differential and wheel bearings for water ingress and replace fluids and lubricants as soon as possible.      

Do not remove the master cylinder reservoir cap in wet weather or humid weather except in emergencies. Most reservoirs are now transparent to eliminate the need to do this. The boiling point of the brake fluid drops significantly in contact with humid air. Brake fluid is more anhydrous than silica gel.

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