ColinK82

just finish building up my stroker motor, and the coolant side has a edelbrock high flow water pump, elec fan, alum rad with a moroso overflow.

here's the issue, it's fine when i drive it, but when i turn the car off, the rad completey drains itself into the overflow and will keep going till the overflow starts draining , and will stop when the rad is almost empty.

why the **** is it doing this?

67mustang302

Do you have the right radiator cap, is it good?

ColinK82

just the stock rad cap, seems in good shape.

can that have an affect on anything?

67mustang302

Yes. The cap has springs in it that hold/release pressure. If the cap goes bad then you can have problems. There should be a way to check it, and replacing it is pretty cheap. Could be the wrong cap for your setup too

M95

I also think that the cap is very important. I thought mine was alsoin good condition but I have discovered that the water doesn't go into the extended reservoir. I don't think that it's good as there is a pressure when water is hot. I have to buy one.

tinman

+1000