Andy --

Replacing the boot will only hold the leaking fluid in -- it won't stop the leak. Sorta like internal bleeding.

I had exactly this on one car ('83), left side. I turned the wheel way to the right, sprayed parts clearer up around the rack, and blew it out with compressed air. Amazingly, the leak stopped. I think a speck of grit may have been caught under an O-ring, and I washed it out.

Then I sprayed ATF in there and installed a good boot. It hasn't leaked for the last four years.

Probably a one-in-a-hundred chance of that happening again. On two other 240s I've replaced the rack.

BTW -- if that boot has been torn for awhile, the steering rod inner ball joint might be starting to rust and get sloppy. If it's still OK, be sure to pack some good grease around the ball 'n socket portion before installing a new boot. Since you'll have the outer end disconnected for boot replacement, be sure to rotate the ball 'round 'n 'round to spread the grease around.

Inspect the other side, too.