Know that sinking feeling you get when you walk towards your car and see a puddle of fluid under it?
There is a lot of uncertainty around leaks and what they mean; some may be harmless, others are far more serious.
If you find a clear watery liquid, that’s likely all it is – water, from condensation out of the air conditioning system. Air con collects water in a drip-tray below the evaporator and the tray is then drained through a small tube under the car.
This leak is more likely to appear after you’ve been driving and have recently parked, especially in hot or humid conditions. It’s usually nothing to worry about and quite normal.
However, if the drain becomes blocked you can also see a clear fluid, which leaks into the cabin. This is something you do need to worry about and should get it unblocked, to avoid damaging internal electrical components.
Many modern vehicles have washer reservoirs located behind the front bumper in a vulnerable position. If your vehicle has had a minor collision the reservoir can split, or the hose can become displaced. This will cause your washer fluid to leak, creating a soapy spill.
This is not too serious, but should be addressed and in most cases can be accessed and remedied without the removal of the front bumper.
Brown, black or amber oily fluids
These are usually engine oil leaks. In older cars these are more common, as seals and gaskets wear and break down. A modern vehicle shouldn’t leak any oil; the usual suspects on a newer vehicle are a faulty sump plug gasket or leaking oil filter seal.
Red or brown
This is typically automatic transmission fluid. As the fluid ages it turns from bright red to brown and may also have a burnt smell.
Transmission fluid leaks could come from a variety of areas such as coolers or axle seals. If the transmission has recently been serviced, check for obvious sources like the drain-plug or pan-gasket.
If you have a major leak such as a blown external transmission cooler hose, once it has exhausted the fluid the vehicle will stop driving. If this happens, do not attempt to continue as you may cause further damage to the transmission assembly.
Transparent yellow or brown
Brake and clutch fluids are usually yellow or clear; if you have a brake fluid leak your brakes or clutch may fail.
Have a look under the bonnet. There should be two reservoirs; if you find that either are low, it will indicate whether the leak is related to the clutch or braking system. Faulty brakes are especially dangerous.
Green, orange, pink or blue
These leaks are usually coolant; manufacturers use bright colours so that coolant leaks are easily identifiable. Coolant has a watery consistency and also a sweet smell, so if it leaks onto hot components like the exhaust it can create a lot of steam, too.
Common potential issues include a loose hose clamp, leaking water pump or radiator failure. You could also have an overheating issue, causing the coolant to overflow. Any of these issues should be addressed as soon as possible, because if you run out of coolant and the engine overheats it can cause a lot of damage.