www.thetford-europe.com
select English of course.
Select customer service
Select user information
Select repair instructions
Select Built in toilets
Select c400 series
Select c402c obviously...first.
Download and save all pdf's there free and your pump is the last which is under the flush leaver as shown in clear cut photo's on the pdf.
You can't go wrong but take dig pictures as you take it apart so you have your own close up of replace sequence. I do that with everything now I'm unsure of or have to leave a while so I don't forget what goes where. simples!!
Hope this is useful as it took time searching on thetfords site.
Bob, June 2011
