i am getting coolant in fuel seperator.Is putting the retaining ring in the sleeve will solve the problem or i have to do the head ?
Put retaining rings. It did solve same problem on my 2015 KW with 500k miles. It cost 400$ with tool and its easy to do it by yourself. I did make video but didnt have chance to upload it. 50k for now since I put rings on and no coolant in fuel.
Once you put rings, make sure you drain coolant from tanks, I'm pretty sure you have lots of coolant in tanks.