08-16-2014, 07:20 AM
I agree with Steve. I would go with the 4" because the extra capacity will insure no backup. I have a 3" pipe where I dump my coach and unless there is a good seal exiting the flex RV hose and the sewer, leakage occurs.
2001 Newell #579
tow a Honda Odyssey
fun car: 1935 Mercedes 500K replica