www.thetford-europe.com
Improved site with many repair instruction downloads on range of toilets.
One way of testing if it is entering via the top of the cassette door is to cover the door with plastic sheeting tape it on with Duck tape , if it still gets wet it may be the flush water leaking out somewhere.
UK	www.thetford-europe.com	
Australia	www.thetford.com.au	
	Australia site has stockist list.	
	FOR UK USERS.	
HOME PAGE 	SELECT 	ENGLISH {if in Australia forget this selection
NEXT PAGE	SELECT 	CUSTOMER SERVICE (tope line) 
NEXT PAGE	SELECT 	USER INFORMATION  (left of pic)
NEXT PAGE	SELECT 	REPAIR INSTRUCTIONS   (left of pic)
NEXT PAGE	SELECT 	BUILT IN TOILETS  [top right of pic] 
NEXT PAGE	SELECT 	C2, C3., C4 (or relevant)  or select your model
NEXT PAGE	PDF Files	YOU ARE NOW IN PDF FILE LIST
                
 Bob
                
 April 2009