I have replaceded my moen 1028(expired-moen didn't even recognize the 1028) to a universal 1225 cartridge,and after 2 weeks it's leaking again(hot water only) with the handle in shut off. Earlier when I pulled out the 1028,inspected the pipe,looks fine.greased the o rings on the 1225 too.The difference between the two is there is a very little size tit on the 1028,whereas the 1225 has none.inside the pipe there is a little indentation for that tit,does it matter?Though I had to bang the 1225 in,especially the last inch with a rubber hammer on the white plastic handle that comes with it,I'm not sold 100% this is the right cartridge,though it worked fine for 2 weeks,please advise

Call MOEN. They have Life-Time warranty. They will tell you - and send you - exactly what you need. Here is US contact info:

Call Moen U.S. 1-800-Buy-Moen (1-800-289-6636)

8:00 am to 7:00 pm EST Monday through Friday
9:00 am to 3:00 pm EST Saturday
Closed on Sundays and all nationally observed holidays.

Let me know how it went.

Back to you / Milo

Moen says the 1225 is right,my challenge is the force it takes to tap it in suggestions

We usually lubricate new cartridge, push it in by hand as far as it goes and than for the last 1/2" or so I take small needle-nose pliers put it on top of the cartridge with stem in-between pliers and push in downward direction. Here, make sure the notches on stem and body line up. You will feel as it snaps into position. Insert "U" pin and your faucet should work OK now....

Here is a clip that may help, too...

https://www.youtube.com/watch?v=pyBTL7GugHo

Hope that helps / Milo