cooling system flush

Posted by Mark Graber On 2016/10/27 0:27:58

I'm hoping to tackle a cooling flush before weather gets really cold. I have a flushing tool and found oxalic acid at the hardware store. Site research tells me to use about 2 cups oxalic and flush engine and radiator separately.
Question: How long should I leave the oxalic in the system before flushing and neutralizing?
Thanks.