My van has no power assist when turning left.

My van has no power assist when turning left when it is cold (below 40), but it comes back after warming up. Another post I read on here said it was bad Teflon seals in the rack & pinion and suggested replacing the unit. (http://www.2carpros.com/questions/chrysler-concorde-2001-chrysler-concorde-hard-steering)

I found a rack & pinion seal kit from a reputable online parts store (rockauto). Would a kit such as this be sufficient, or does the rack need to be replaced? If the kit will work, does the rack still need to be removed to replace the seals? (It if does need to be removed, I am inclined to replace the unit anyway).

Thank you in advance!