Changing engine coolant in 4BY2

[ngleadow]

Greetings;
I want to change the coolant in our 150 4BY2 engine. The manual says to remove the heat exchanger to get at the drain plug. Is there another way of doing this that doesn't require taking off the heat exchanger? Any help would be appreciated.

Norm on Blue Socks

 

[knotflying]

There is a petcock on the side of the exchanger and there is also one under it at the rear. The side one seems to work just as well. Just screw it out until fluid starts to come out and put a hose to a bucket. Open the cap so you get free flow. You will drain about 1.5 to 2 gallons. This is about half. I change it every year since I am not getting it all out. No way I am removing the heat exchanger.

 

[Kaisardog]

if you ever have to remove the heat exchanger, be sure you have the right replacement gaskets as they tear very easily and sometimes can't be reused.