How to Replace Your Milgard Positive Action Lock

Safety Precautions:  Activities in this video are appropriate for individuals with an understanding of how to use simple hand tool.  Make sure that pets and small children are not present when performing these activities.  Questions? Call 1-800-Milgard  or visit

For this project you’ll need a #2 phillips head screwdriver, a new positive action lock, a self-tapping screw, and a putty knife.

Locate the take out clips on the sides of the window frame.  Use your finger to gently pop out the clips at a 45 degree angle.  Now locate the sash stops at the top, they prevent the window from disengaging.  Remove the sash stops.  Excessive force is not needed.  Slide the sash stop until you feel it disengage, make sure both sides catch on the take out clips.  Slide the sash to one side to remove.  Use a putty knife to remove the Milgard logo on the screw port cover.  Use a #2 phillips screwdriver to remove the lock screw in the screw port cavity.  Once you have removed the screw from the positive action lock, the old lock will come loose from the vinyl frame.  To install the new positive action lock, align the new lock tabs with the pre-punched holes in the window sash.  Note, if the screw holes are stripped, you’ll need to slide the stiffener bar over using a #2 phillips head screwdriver.  The stiffener bar is located inside the top rail of the sash.  Using the new self-tapping screw, fasten the new positive action lock to the vinyl sash.  Replace the Milgard logo screw cover.  Re-insert the sash into the window.  Place sash above the bottom of the balancer, lineup and push in.  Balance it back and forth until you feel both tops catch.  Slide the sash down an inch or two.  Make sure you don’t see any metal on either side of the spring.  Push in the take out clips and close the sash.  Re-install the sash stops.