If you read the service manual it suggests changing all the pipes every two years! Nope, not doing that. Ever. Will replace when leaking.
That's the reason I replaced that one, leaking! It was a serious strip down, never mind doing that every two years!!
I just put a brand new cutting deck on it, since the blade bosses were worn and had very slightly bent the deck where they mount. You could start to see the cut lines in the grass. I think I know the culprit, a particular person trying to skim drain covers.
Na, don't do that yourself, best take it to the garage.