Replaced the vacuum toilet system sewer lines.....
Replaced the sewer lines on our coach.. found that the 7' "cross over" sewer line for the vacuum system had cracked, and that two elbows were cracked as well..
for the cross over line used the new length of pipe (with a short piece of smaller pipe that would fit inside to join them together and used the old pipe as a "guide" for the replacement..3 big guys pushing the new pipe,(and a 8# sledge hammer), one small guy "catching" the old pipe out the other side of the coach had it replaced in an hour.....
(btw.. the vacuum toilet is on the drivers side, the vacuum pump is on the passenger side, and the black tank fill point is in the middle of the coach)
Lesson learned (again)...Those who design coaches never have to work on them...
Now to replace all the doors & drawers I had to remove for access... then put the toilet back together one more time...