We are living with a squirting leak on the base of the kitchen swing spout
faucet. The swinging spout seal has been leaking for many years. We've
reported the problem to the landlord. But when the repairman came, he
replaced faucet with a brand new one of the same type and the problem
continues weeks later.

I took the circular seal out from the base (see #13 in the pic below) and
find nothing wrong with it so I put it back in. It still leaks. What are some
ways I can make it stop leaking?

Thanks
Exclude part #17 in this pic http://www.plumbingstore.com/images/valley10.gif