1960 D-ALWINTITE Window Springs

Thanks for contacting us. Looks like you have the old discontinued C-Alwintite window. Your sashes aren't made to come out unless you dismantle the master frame, which is a time consuming job. Fortunately, we can help. To repair these windows you'll need our Series 500 spiral balance, 17-012 bracket, and 75-005 charging tool.

Now let's talk about replacement. When I used to repair these balances, I would drop the new balance behind the sash and screw it in at the top. Then with a helper holding the sash up, I'd pull three or four inches of the rubber weatherstrip from the bottom end and install 17-012 bracket with some 33-085 screws (or any similarly sized screws you happen to have lying around) under the sash. 

Next, charge the balance with the 75-005 tool. You want to give it three or four clockwise turns then lock the balance "T" between the 17-012 bracket forks. Repeat other side. Try the sash. If it creeps down give it another turn or two, but no more. 

When you're all done, work the bottom rubber weather strip back in its groove.

I'm not sure what kind of seal that might be. We  offer a ton of different kinds of weatherstripping for windows, but we'll need a photo of yours to determine if one of ours can replace it. Specifically, we need to see the end profile so that we can make out the shape. Let me know if that's possible.