I've been having a slow coolant leakage problem on my Favorit & have been round it this morning with a screwdriver on the hose clips & a spanner on the thermosensor. Hopefully that will help matters. If not, I'll have it looked at properly. Either way, I could do with knowing the correct proportion of water to anti-freeze. I've been topping it up with water during a busy week & suspect that it could do with a bit more anti-freeze in there now.

TIA,

Gavin.

It's usually 50%, 3 litres is enough for a complete coolant change.

Have you checked the rad cap?? If the rubber has perished, even a little, it will lose a little coolant every time the system gets hot.

As GentleGiant says. Actually, even if the rubber is fine, if the pressure spring is weak you'll still lose coolant every time the engine gets fully hot.

True Ken, but the caps I have bought over the last few years have had such ****e rubber seals that they only last 2-3 years, and the metal spring usually lasts much longer than that.

I used to re-do mine with a red engine sealant (cant spell the name, but it starts with "H" :-)

At least, I did until the last local auto parts shop closed last year, now we only have c@appy Halfords; who dont stock it :-(

You can get a plastic insert for the tank which is designed to deflect the coolant entering the tank through the small hose away from the upward moving vapour that vents through the cap.