Caldwell window balance spring

Question

Hi, I need to replace my window balance springs. Attached are the pictures of my old ones. They both have stamps "26 4 LO CALDWELL". Could you please help me to identify what is the correct replacement part I should purchase? Thank you for your help!

Bob · Accepted Answer

Thanks for posting. This looks like either the S380-27 or the S385-27 Channel Balance, depending on the depth of the bottom nylon shoe. See below. Measure your old balance's shoe depth to see what matches best. For a stamp option choose 2640.

Comparison of the S378, S380 and S385 balance shoes.