Auto Academy: What to Do When Fluid Leaks From Your Car

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Rear differential flush
Rear differential flush | Micah Wright/Autos Cheat Sheet

As a driver, few things are more disconcerting than realizing some sort of liquid is leaking profusely out of your car and you have to be somewhere in half an hour. In the past I’ve covered the basics regarding some of the easier maintenance work you can do yourself, and while no amount of preventative maintenance can make a car last forever, it can greatly lengthen its lifespan. So if you happen to see liquid leaking from your vehicle, there are a few things that need to be done to protect you and your ride.

First, determine if you actually have a leak. Air conditioning evaporators purposefully drip excess moisture onto the ground when the unit is on, causing countless drivers every summer to think they’ve got an issue, when actually everything’s perfectly fine. If it isn’t evaporator water, try and diagnose what fluid is leaking. You don’t want to add a bunch of extra antifreeze when a cracked windshield washer hose caused a bunch of bug cleaner to leak out. Poking your head around under the hood will help deduce what’s leaking and why; just be careful if you’ve been driving a lot, ’cause that engine is going to be hot!

Brake reservoir
Brake reservoir | Micah Wright/Autos Cheat Sheet

Once the culprit has been found, it’s time to take the next step, which typically involves some key decision making. You’ll need to decide whether you should contact a repair shop (or dealer) and risk driving the vehicle there yourself, pay to have it towed somewhere, or fix it on your own. If it’s just a split upper radiator hose, most casual gearheads can tackle that themselves. But if the radiator is compromised, or there’s a sudden major oil leak, it might be best to leave it up to the professionals.

Naturally, if you suddenly spring a leak while driving, pull over to the side of the road and call for assistance because driving a vehicle without ample amounts of fluid is about as advisable as eating a Taco Bell Grande Meal and then going jogging. Most automakers offer extended services, where buyers get unlimited roadside assistance, so if your vehicle is still under warranty, chances are you won’t have to pay for whatever has malfunctioned.

Brake fluid reservoir
Brake fluid reservoir | Micah Wright/Autos Cheat Sheet

But for those of us who buy used, or insist upon keeping a classic running properly, the option of having a dealer take care of everything for free is out of the question, and we have to fend for ourselves. So here are a few key DIY tips if fluid loss is an issue.

Once the problematic component has been exposed, a replacement part has been sourced, and the issue is now fixed, make sure there are no other issues with your car. You’ve got the hood up anyways, so you might as well poke around to inspect belts, hoses, other fluid levels, and various other tune-up components. Once no other potential issues have been found, it’s time to refill whatever liquid was lost during your little setback. But not all automotive fluids are made equal, and while an “all-in-one” solution may sound enticing, 90% of the time it is best to replace fluids with what the manufacturer recommends in the owner’s guidebook.

Topping off fluid
Topping off fluid | Micah Wright/Autos Cheat Sheet

For example, older Hondas have power steering pumps and seals that are notoriously finicky, so spend the extra dough and buy legitimate Honda power steering fluid instead of saving a few bucks and getting the knock-off brand. There are also certain antifreezes that work best in certain makes and models, and while a 50/50 blend of all-encompassing coolant may work in the short run, that’s rarely advisable.

Hell, if you’re replacing an entire radiator and all of the components that go along with it, you might as well make sure the fresh fluid that’s getting dumped into it is what the dealer recommends in order to guarantee that you don’t run into this issue again.

So for those of you who are unaware of what to do when things get messy, know that the handbook in your glovebox is always there for a reason. And if you’re ever in doubt, you can always take a picture of the problem and send it to a gearhead buddy or family member. With a little luck they can help diagnose the issue and offer the best direction for you to take so your car doesn’t end up on an extended vacation at the mechanics, or worse, a one-way trip to the scrap yard.