Toliet Gate Valve operating lever

My 2010 Devon M/H toliet gate valve lever has developed a loose operating action. It still open and closes the gate valve OK but the lever seem to come out of its pivot point. Removing the waste tank doesn't reveal the lever operating mechanism which seems to be between the swivelling pan and base? Is there away to reconnect this lever back to its pivot point please? Thanks J C.

I don't think anyone will be able to help without knowing the make/model of the toilet unit. There is usually an identification label somewhere inside the cassette compartment.
Keith

Thanks Keith will look today. However I thought the Thetford toliet units were pretty much generic with the gate valve arrangements?

Maybe but Theford aren't  only manufacturer, so we are at least one step forward with info to inform  those who may be able to help

Is this any use?

https://www.youtube.com/watch?v=v81LDXaQ6u4

Thankyou Roger, very informative. I've sorted the problem. It wasn't the actual blade assembly but the operating handle. Some how it lost its fulcrum attachment. Some washers and a self tap screw solved the problem. Thanks all for your help. J C

Windsurf1: I wonder if you'd mind describing in detail, step by step, what you did to fix the issue, please? 

It's such a rare problem that it would be good to add the solution to the Factsheets, if Ed will agree.

Thanks,

Cymro