How to Check Transmission Fluid in Your Automatic Car

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Hold onto your hoods, some summertime fun coming at you! If you own an old car with an automatic transmission you're going to learn how to check the transmission fluid. I mean, honestly can you imagine anything more exciting? No need to answer that.

Old black volvo with the hood up and engine showing.

Unlike engine oil, or washer fluid, transmission fluid isn't something that you car uses up. If you're losing fluid it's because you have a leak.

I admit I'd never checked my car's transmission fluid until one day a few weeks ago I thought - huh, I wonder how you check transmission fluid. These are the important thoughts I have.

I was actually looking at my cloudy headlights thinking it was time to get out the sandpaper and clean my headlights again.

The reason I mention older, automatic cars is because some newer cars have a sealed system. Technically the system should never leak and the fluid should never need to be changed over the car's lifetime.

Of course, in general, steering wheels aren't supposed to fall off in your hands over the course of the car's lifetime but that's been known to happen. Like with this Tesla. So.

The easiest way to know whether you have a sealed system is to open up the hood and take a look.

If you can't find a transmission fluid dipstick, you have a sealed system. Or bad eyesight. To double check Google your car's make, model and year or check the owner's manual.

Pulling yellow automatic transmission fluid dipstick out. — ATF = Automatic Transmission Fluid

Table of Contents

How to Check it

Park your car on a level surface.
Find the transmission fluid dipstick. It will be yellow or red/orange.
If your dipstick has easy access then start your car and let the engine run for 10 minutes. (it's best to check fluids when the car is hot)
If your dipstick is NOT easily accessible DO NOT RUN YOUR CAR. It'll be too easy to burn yourself if you have to reach your arm down into the hot engine.
Pull the dipstick out - it may have a little spring locking device on it that you need to release first.
Wipe the dipstick clean with a paper towel and look at the colour of the fluid*
Reinsert the dipstick and pull it out to check the level. On a cool engine it should be at or slightly above the COOL line. And on a hot engine it should come close to the HOT line.
If it's lower than expected you should head to the mechanic.

Symptoms of Low Transmission Fluid

Before you go getting your arms dirty, these are the signs your fluid might be low.

You can see a leak of something pinkish or red under the car.
Gears are slipping.
Poor acceleration. Your car doesn't feel zippy.
Burning smell. (This is pretty much always bad with regard to your car)
Gear engagement feels chopping or sounds unusual.
The Check Engine light is on.

If any of these things are happening it's not a bad idea to grab a paper towel, roll up your sleeve and check your transmission fluid.

Would you like to save this stuff?

We'll email you this post, so you can refer to it later.

Here it is in video format - you'll see that the dipstick in my Volvo is hidden within the guts of my car so I checked my fluid on a cold car.

Hand holding up yellow transmission fluid dipstick prior to wiping it off.

When you're in there, arms and hands covered in dirt you want to do more than just check the fluid level - you also want to notice the colour of it.

What Colour Should it Be?

Brand new transmission fluid is clear red. Over time the fluid will become less clear and that's fine. Once it turns brown and opaque you'll want to get the fluid replaced.

Red & Transparent = New oil, you're good.
Reddish Brown, semi-transparent = Still Good
Brown, opaque = Needs changing/flushing
Brown/Black, opaque = Needs changing/flushing
Light pink, means it's contaminated with water or coolant = Uh oh. Transmission replacement is in your future.

Automatic transmission fluid with good, light brown/red colour.

Don't fret too much (especially if your car isn't showing any symptoms of low fluid) if the fluid isn't EXACTLY on the Cold or Hot mark on the dipstick. As long as it's in the range you're good.

And lastly because sometimes it helps you pay attention to things if you know WHY you're paying attention to them.

What Does Transmission Fluid Do?

Transmission fluid keeps your car's gears and metal transmission parts lubricated and running smoothly. Old, dirty fluid is filled with particles that hinder the slip of it. This in turn causes gear trouble.

Can I drive my car if the transmission fluid is low?

Just to the mechanics. And even then you're taking a chance. Drive no further than a 15 minute drive and don't drive like a jackass. Drive slowly - straight to your mechanic.

What if it's reallyyyyyy low?

No. If your transmission fluid is alarmingly low (well below the lowest acceptable line on the dipstick) you shouldn't drive it. Either get it towed to a mechanic or if you're sure you don't have a gaping hole in your system, refill the fluid and head straight to your mechanic.

If you thought THIS was exciting (I mean it wasn't, so I'm not sure how you think that) you're going to really love learning how to jump start a car. Living in Canada this is something I have extensive experience with - always in the winter and always when I don't have time for a dead battery.

If unlike me, you're driving a brand new Tesla instead of a decade old Volvo you don't need to worry about any of this. You just need to worry about your steering wheel falling off in your hands.