In 10 years full timing with what appears to be the same Thetford toilet. We've had 3 leaks at the rear of the toilet:
- The vacuum break failed
- Supply hose from valve to vacuum break, hardened and would not seal with factory clamps
- The valve same as yours.
Also the return spring has broken twice, never hurts to have extra parts around. At present I have a ball valve repair kit, 2 floor seals and a return spring as repair parts with us. I have changed all the clear plastic hoses which hardened and "yellowed" over time to braided vinyl hose
