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How to detect auto leaks like a pro

2014 Audi A4 Allroad Quattro all-wheel drive wagon
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EDITOR’S NOTE: This article is part of Car Deal Expert’s historical archive. The UK car-finance, insurance and used-car landscape has moved on since this was published. For our latest coverage, explore our Car Finance, Car Insurance, Buying Guides and News sections.

Originally published 2011-10-23. This article is part of the CarDealExpert historical archive — see our latest UK car-finance, insurance and used-car coverage in the menu above.

If this is how your car greets you in the morning, perhaps it’s time for a refresher on detecting auto leaks. (Photo Credit: CC BY-ND/sky_mitch/Flickr)

Whether it’s engine oil, transmission fluid, antifreeze, battery acid or air conditioning Freon, detecting auto leaks is essential to maintaining proper function of your vehicle. Some leaks can be seen, others have a distinct odor and some require more detailed inspection, according to Machinery Lubrication. Here are some detection and prevention tips and tricks for the DIY auto jockey in you.

Leaking engine oil is a common occurrence

Considering that an engine has anywhere from 150 to 200 components that rotate at 2,500 rpm under normal driving conditions and there are numerous “soft points” in the system, the potential for leakage is great. Watch the front and rear crankshaft seal, oil pan seal, gaskets, timing cover seals and other areas where oil comes in contact. Oil stains on the driveway or road are obvious signs, but Popular Mechanics suggests a trick called “dusting for oil leaks” when things get tricky. Essentially, it involves cleaning your engine off, then spraying foot powder around the outside. After running the engine for a couple of minutes, fresh oil will soak into the white foot powder and leave a dark stain.

Air conditioning and transmission leaks

Freon or a related air conditioning refrigerant is hard to find when the leak is slow. Adding more Freon will quickly expose fast leaks, but slow leaks may require the use of a propane flame. Understandably, this is something that should be left in the hands of a trained automotive technician, unless you’re completely confident with a car. Similarly, transmission leaks can be difficult to spot. “Because of their location, under and to the rear of the engine,” writes Machinery Lubrication, “an engine oil leak will ‘mask’ a transmission leak.” Put some cardboard under your car in order to discover whether you’re dealing with a front- or rear-transmission leak.

Power steering, brake and battery leaks

Since power steering is a high-pressure system, turning the steering wheel creates a great deal of pressure on hoses in the power steering system. The turn of the wheel will more than likely reveal the leak. With brakes, the fluid has a recognizable smell and texture. Brake fluid leaks can be found when one person depresses the brake while someone else watches underneath the car for leakage. Battery acid simply smells horrible. Your nose won’t miss the rotten egg smell of hydrogen sulfide gas, which typically comes from an overcharged battery.

Smoke, mirrors and dye

Using a smoke generator connected to a vacuum line, intake or exhaust manifold can reveal leaks, as can conveniently placed mirrors on pivots when line-of-sight identification is impossible. Finally, using a principle similar to smoke detection, there are non-toxic fluorescent dyes that can be added to the above fluids to make leaks easier to spot.

What do auto loans smell like? Victory, of course

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Sources:

Machinery Lubrication

Popular Mechanics

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