Rad or Expansion?

[halkewl]

I have been checking all the threads on here and I am confused by the different opinions on how to check and top up coolant? Some say check by the expansion tank others say Rad ? filling is the same some say expansion others rad ? which is the corect way to check? and which is the correct way to fill?

[da SLUG man]

I have been checking all the threads on here and I am confused by the different opinions on how to check and top up coolant? Some say check by the expansion tank others say Rad ? filling is the same some say expansion others rad ? which is the corect way to check? and which is the correct way to fill?

fill the rad to the top... the expansion bottle should be about half full, so long as the end of the pipe's covered so it doesn't suck air in.

[Greebo]

I have been checking all the threads on here and I am confused by the different opinions on how to check and top up coolant? Some say check by the expansion tank others say Rad ? filling is the same some say expansion others rad ? which is the corect way to check? and which is the correct way to fill?

Like the big man says ALWAYS fill and top up by the rad cap. expansion bottle is just for taking the overflow when it gets hot and holding it till it gets sucked back in to the rad as it cools.