Getting old I can no longer compress the spring enough to get the push rod back on the slide after cleaning. I have noticed the plastic black end seems worn at the edges all around the circumference. This end keeps sliding off as I try to compress from the blue end. Do I need a new rod? If so, does it come with the blue and black end? Will I need a new spring, and are softer springs available that will work? I need some suggestions here. Many thanks.