Okay, forgive me for asking this question. I've searched on the forums and on google. I get different answers and I'm just wondering.

I've always filled up my radiator to the top and put the cap back on and drove it like that. The temperature has never went pass a little before the centre of the gauge. So, I figured the car doesn't have a heating problem because of that. But, I could never tell how much fluid was in my radiator. I was told there was the overflow tank. So, I found it and looked inside of it. It's completely empty.

So I googled for a couple of days and get mixed answers. Half of the answers tell me to fill it up to max and also the radiator, while the others tell me to just fill up the radiator only as the overflow tank is only for when it heats up and spills the excess into it.

On my domestic car I've only see the plastic tank and kept that filled up as I couldn't find the radiator cap. It never overheated.

So, should I keep both full, or just the radiator?

Another question. If the coolant level goes down. Does that mean there is a leak, or normal? Sorry, I am currently a little inept on this, although I am trying to gain knowledge. So, please, don't flame me

 

When the engine is cold fill the reservoir tank to the max mark. Fill the radiator up
to the top if its low. Every time you next check your fluids, top up the reservoir
if it needs it. You dont need to fill the rad, if the systems working correctly.
Make sure the pipe between the rad and res. is clear and the connections are
air tight.

 

^^Right on

 

You need to fill the rad as it does push out fluid as pressure is to high via the spring in the cap but will also pull fluid back into the rad as it cools and you dont want it pulling in air and getting traped in the system

 

The overflow tank has a mark around the middle of it. This is your "max fill" mark. You don't fill it up more than about half of the entire bottle...just to that "max fill" mark. When your car heats up the system expands. When this happens coolant will rise in the overflow bottle. If you fill it up too much and your car warms up, it will overflow that bottle. When the system cools down the coolant will go from the overflow back into the coolant system.

The radiator itself should always be full when you open it, in fact coolant should almost squeeze out when you open it. If not, then you probably have a leak somewhere.

 

Thank you guys .

 

how often do you have to add coolant?

 

last time i remembered that "coolant resorvoir" is for over flow not to store coolant.

when the engine reaches excessive pressure and head the radiator caps springs up(thats why theres a spring in there) and releases excess pressure through the hole inside the radiattor and into the resoirvor thats why when you over heat theres steam in there.

 

I don't know how often I refilled it. Since I rarely gotten to drive it much.

 

hm, well if its more than rarely then you should take a look around to see where its leaking, hoses(&connections) are a good place to start looking. ex. i have a crack on my rad, only drips if i turn it off right after hard driving. which is why you should keep fluid in the resovoir so when it cools it can pull in the coolant it needs. you have great advice up top, keep it in mind next time you look through your coolant system

 

Agree

 

If it's not leaking anywhere, you may have a blown headgasket and it's getting burned off with the oil.

Worse case scenario. Don't overfill that radiator tank.