how to check anti-freeze freeze level

[jbudd21]

So the other day me and my dad were checking the anti-freeze freeze levels on our cars. And it says that the car should be warm when you check this. So I warmed it up and opened the hood, to notice that the overfill is connected to the radiator and reads " do not open when hot" on the cap. So how do i go about checking the freeze level?
Thanks,
Jim

[M3Alpine99]

"Check the freeze level"?

I assume how resistant it is to freezing... IE Anti-Freeze.

It depends on the 1/2 of water to Anti-Freeze. What percent did you do?

[jbudd21]

thats the thing. I haven't changed the anti-freeze since i bought the car. it has the FDM mod done, so I assume there is some water wetter in there.

[DeanR]

There should be a line on your expansion tank to fill to when cold. There is no need to have the car warm. Also there is a big difference between an engine at proper operating temperature and an overheating engine. The cap on the overheated engine should not be opened. If you are bleeding air from your system and adding coolant you will have to take the cap off. I open the bleeder screw first to check if it is safe to open the cap.

[yeomgon]

You mean the freezing point of your coolant, right? Go to autozone or advanced autoparts and ask for a 'coolant tester'. It's a simple tool(costs less than $10) you put some coolant in (more like squeeze in) to find the gravity of the coolant. DO it ONLY when the coolant is COLD.

[johnnybmw1]

drive it for a bit, shut the car off, wait 5-10 minutes, pop the hood.
look at the damn level on the coolant container. pretty simple. OH YEAH OH YEAH

[jbudd21]

You mean the freezing point of your coolant, right? Go to autozone or advanced autoparts and ask for a 'coolant tester'. It's a simple tool(costs less than $10) you put some coolant in (more like squeeze in) to find the gravity of the coolant. DO it ONLY when the coolant is COLD.
Yeah, we have one of the testers but my dad said to do it when its warm. I guess hes wrong. Thanks.