Welcome to the forum, there is two things that I can think of, after you get water in all the lines check to see if there are any leaks, make sure to check every fitting. Then after you have run water down each drain look to see if there are any leaks at the drains.
Water leaks can and will cause a lot of damage if it goes undetected.
2015 Jay Flight 23 RB
2014 Silverado LT 1500 with a 5.3 V8 Ecotec3