Dealing with automotive fluids might be one of the more miserable the unsung inconveniences of being your own mechanic. And even if you pay somebody to maintain your car, it’s important to know the age and condition of your car’s various bloods.
Changing your car’s fluids is critical, and, usually, designed to be pretty easy. Your oil, brake and clutch fluid, transmission fluid, coolant and even power steering fluid are meant to be serviced, and changing them on time keeps your car sweet and responsive for more miles. But it still leaves you with vessels of toxic poison to dispose of. Here’s a front to back guide on what to do there.
Why Flush Fluids
All automotive fluids expire after so many heat cycles and months in service. It happens to your motor oil going sludgy; it happens to everything.
Car fluids are chemically engineered to flow a certain way and maintain specific temperatures. As they age, they lose these properties and become less effective. As that happens, the components they’re in wear down more quickly and don’t work as well as they should.
Brake fluid, for example, has a high boiling point, low viscosity, and anti-corrosive properties. When you hit the brake pedal over and over again, the fluid that flows down to your brakes to clamp them closed gets hot. That’s not a problem when the fluid’s clean.
But brake fluid is hygroscopic, which means water in the air eventually contaminates it. Once that starts to happen, it boils more easily. If your brake fluid boils, there will be less of it, and air bubbles, in your brake system. By then, if you go to pump the brake pedal, there will be less juice to flow to the brake caliper, and that will mean you won’t be stopping in a hurry.
Splurging on a $15 bottle of brake fluid every few years could make the difference between your brakes working well enough to prevent a crash, or, not.
When It’s Time For New Fluid
Generally speaking, automotive fluids start clear or nearly-clear and get darker as they age. You usually pour them in looking like Miller Light, and you want to change them when they start to have around the opacity of Sam Adams. By the time they look like Guinness, you definitely want to think about refreshing.
But actually, you’re just going to want to Google around for your car’s factory service manual then consult said manual’s index. The correct change intervals will be findable from there, and that book will tell you exactly what type of fluid you’ll want to add, which is important too.
If you’ve got a new-to-you used car and you don’t know how old its fluids are, it’s not a bad idea to baseline everything and do a full refresh.
Why Flush Fluids Yourself
Changing fluids on most cars isn’t hard, but it is time-consuming. That makes it the perfect task to avoid outsourcing since you might pay a lot for labour time on something you might be able to do yourself.
But more significantly, if you change your own fluids, you get to pick out the best chemicals for your car. And you’ll get very familiar with the underside and underhood areas of the machine.
Why Have A Pro Flush Fluids
Again, changing fluids on most cars isn’t hard, but, again again, it is time-consuming. Some people find their time more precious than a mechanic’s fees, so if that describes you, go ahead and outsource.
It’s also pretty icky–dealing with toxic fluids isn’t everybody’s bag, nor is rolling around under your car, and it can be hard to grab a buddy to bleed brakes with you.
Don’t let anybody shame you into feeling like you’re not a “real car enthusiast” if you don’t change your own oil. But do take the time to research a reputable repair shop, maybe even one that specialises in your type of car, if you want someone else to do it.
How To Prepare To Deal With Fluids
Assuming you do decide to attempt your own fluid flushing, let me emphasise the most important piece of advice in this post: Always wear eye protection and skin protection when doing this kind of work.
Once more, for the people in the back: Get good safety goggles and gloves, and wear them, before you start cracking drain plugs. The time I got carburetor cleaner in my eyeball was one of the most painful experiences of my life, and that’s saying something… I’ve had a UTV roll over onto my hand, I’ve had my AC joint split by a kangaroo, I’ve had my share of knockouts and pain.
Anyway, besides being suited up like it’s eighth-grade chemistry class, make sure you’ve got plenty of trashy rags around and a good vessel to catch old fluid in.
I’d recommend using a vessel you don’t mind surrendering when you dispose of your waste fluids, as some places might make you just leave your whole bucket. More on that later. Whatever bucket you do use, keep in mind that the fluids you’ll be catching are caustic enough to eat through some plastics. A glass jar might be a good option if you can find a cheap one (check the home goods section at a joint like Ross and Marshalls or TJ Maxx). Finally, you’re going to have to cart this to a disposal site, so use something that won’t easily be spilled from.
Draining And Refilling
Each car and, of course, each component is going to have its own flushing process. Consult that factory service manual I mentioned for specific instructions and online forums for people who own your kind of car for wisdom that might help you preemptively prevent mistakes.
Generally speaking, you’re going to want to avoid letting a hydraulic accessory run completely dry, and never start a car with any of its fluids depleted.
How To Figure Out How To Dispose Of Fluids
Pretty much every home-wrenching car enthusiast I talked to gave me the same response when I asked what to do with old auto fluids, something to the effect of “I don’t know, I’ve just got a big vat in my garage.”
Listen, you don’t have to live like that.
Pretty much any auto parts store will take used motor oil, which is fairly common knowledge, but it’s not that much harder to find out where brake fluid, coolant, and all the other juices need to go when they go bad.
Start by Googling household waste collections in your area–some councils run events every so often where somebody might even come to your house to take castoff poisons.
Auto fluids are typically considered “household waste” and while they can’t go in your regular trash, your council or a council nearby will have some provision for taking it which I bet you’ll find by searching “your council + waste disposal” or something similar.
Bigger cities will have permanent collection centres for such things. You can start by calling or emailing your local member, or skip straight to your local sanitation department if you can find its number.
Here in west Los Angeles, about five minutes of cursory research revealed I can take the jar of old brake fluid I just extracted from my Mitsubishi Montero to a placed called the Hyperion Treatment Plant, and lucky me, they’re even open on the weekend.
Now that I know my truck’s got fresh brake fluid I can rest easily knowing not only that I’ll be stopping as well as I can, but also that I can throw out the toxic old fluid legally and ethically without being inconvenienced that much. It feels good!
You might hear about people pouring waste fluids down drains and into holes dug in yards. You may also realise that you can just leave some of this stuff out to evaporate. I don’t have any proof that government disposal centres really do anything “better” for the environment than that, but I’ve got a pretty strong hunch they’re not, say, harvesting these fluids and using them for mind-control devices.
If nothing else, disposing of your chemicals the right way makes all auto enthusiasts look good. Dumping it in a big puddle behind your house makes us look like greasy cretins. Do it for us!