Your vehicle’s radiator – and the coolant system in specific – is responsible for keeping your car rolling down the road without any issue.
Every car on the road today has hundreds (maybe even thousands) of tiny controlled explosions happing under the hood every minute. These explosions cause heat to build up, and if the temperature gets too crazy in the engine bay the core parts and components of your vehicle can become compromised.
Combine that with the amount of heat generated just by the friction of different metal parts rubbing against one another (oil works to mitigate some of that heat, but it can’t handle all the heavy lifting) and you’ve got a recipe for disaster without proper cooling.
To keep things cool, though, your vehicle needs a pressurized system to work the way it was intended.
Any leaks – even tiny ones – can cause serious failures later down the line.
Worse, these issues almost always happen when you’re miles and miles into a road trip and nowhere near a garage.
Let’s run through (almost) everything you need to know about using a coolant pressure tester to make sure you’re all set!
Is It Easy to Check Coolant Pressure?
Believe it or not, the process for checking your pressure levels in the cooling system is relatively simple and straightforward.
First, you’re going to need to make sure the engine is off – and has been for a while.
You don’t want to popping the hood of a car (and then opening the radiator) when it’s been running for a while. That’s a surefire way to make sure you get burned or scalded – or worse!
From there you just hook up a halfway decent coolant pressure checker, follow the instructions (which we include below) and confirm that everything is a-ok.
Let’s jump right in!
How to Use Coolant Pressure Tester – Step By Step
Make Sure Your Engine is Cold Before Testing Pressure
As highlighted above, the very first thing you need to know when using a pressure checker on your cooling system – or doing anything with your cooling system, for that matter – is make sure that your engine is ice cold.
This means tackling a project like this when your car has been sitting for a while, maybe first thing in the morning.
If you were to open up the radiator cap on your car when it was still hot, that pressurized coolant is going to come screaming out – and it’s going to be boiling (hotter than boiling, even).
That’s not something anyone wants to have to deal with.
No, you need to make sure your engine is cold before you start this project. If you can rest your hand on the radiator cap and hose without feeling any heat you’re good to go.
Pop the Top and Check Coolant Levels
The next piece of the puzzle is to simply pop the top on your reservoir and have a look at your coolant levels.
Sometimes pressure issues are immediately apparent, especially if you can see that there’s either too much coolant in your tank or too little.
If you have too much coolant, the odds are good that your tank is going to be running with excessive pressure. This can cause problems with your hoses, can cause overflow issues that turn into electric problems, or just gum up the works of your engine.
If you have too little coolant, though, you might not be getting enough pressure in the system.
When this happens it can be just as destructive, if not even more so, than when your coolant is too high.
Low levels mean not enough coolant will get pushed to core parts of your engine. That means your engine is going to run hotter than it should, and that’s a recipe for all kinds of stuff to go wrong.
You might not have engine fires to put out (though this can certainly happen!) but your parts are going to suffer and be subject to a lot more wear than necessary. The vehicle will breakdown sooner than it would have otherwise.
Apply Pressure Tester to the Radiator
After you’ve checked the coolant levels it’s time to pop the pressure checker onto the radiator cap extension.
Almost all pressure testers come with adapters to fit every make and model under the sun, so you should be good to go. Just test a couple until you’re able to find the one that fits your vehicle best.
Make sure the fit is nice and snug before you do anything else. You really want the tester to be screwed down tight – sometimes even tighter than your radiator cap would be.
Pump Pressure Per Instructions
Now it’s time to pressurize the checker itself.
These systems will either come with a hand pump to apply pressure manually or an electrical system that lets you add pressure deliberately that way.
All in all, you need to be sure you pump the PSI level to the rating listed on your radiator cap (or your owner manual).
DO NOT GO HIGHER THAN THOSE PSI RATINGS!
Let the Pump Sit for a Minute (Or Several)
After hitting the PSI level that you are looking for it’s important to let the pump and pressure checker sit for a minute (or several).
This is going to stabilize the pressure throughout your coolant system and your radiator, including throughout all of the different hoses. You’re going to be able to detect any leaks, any cracks, or any trouble spots that might have been compromising your coolant pressure in the first place.
You’ll know if everything is good to go within about 15 to 30 minutes, though.
Release Pressure on the Pump Before Removing and Replacing Cap
If everything checks out and your system is holding the PSI that your pressure checker has locked in you should be all set!
Before you unscrew the pressure checker from the neck of your radiator, though, make sure that you release the pressure through the pump itself.
When you skip this step it’s just like opening up a red-hot engine and letting all of that pressurized (superheated) coolant come flying out at you.
Depressurize the system, remove the pressure cap, and then replace with your radiator cap (or fill up with any necessary fluid and then replace the top) and you’re good to go.