The original toilet in our Westfalia was leaking fresh water (small trickle from base) when flushed, and was leaking a lot when it was hooked to city-water. We took it for repair and the guy said that he could replace the toilet for cheaper than he could repair the leaky gasket/valve whatever he said it was. He replaced it (used Thetford brand) and it looks great! However, no water flows when you depress the lever to flush. It will flush if the kitchen or bathroom sinks are on. That's not a workable solution in my opinion. The repairman is now claiming that the toilet 'must be' plumbed through the kitchen sink, and he can think of no other reason for this issue. He said the toilet 'must have always been like that'. We've only owned this since Aug, but still I'm fairly certain this would've been a quirk I'd have noticed! He claims I must be wrong. Anyhow-does anyone understand the plumbing enough to tell me this guy is wrong? Does anyone have a clue what might be going on here?