Tried to fix a broken cable on my Thetford Aqua Magic IV toilet. Our local RV shop ahd a cable repair kit in stock so I didn't even have to go to Boise (70 mile round trip. Took it apart and spent an hourt cleaning it. Yuck! 15 years of gunk!!! Then tried to remove the cable retaining screws and they just fell apart from rust. Tried to drill out the remains but alas, no luck. Took back the cable repair kit and bought an Auqa Magic V. Installed it in 100 degree weather and it works fine. So glad to have a good RV shop in a small town.