My old KHS came with a RockShox Indy XC fork, which for the longest time just bottomed out and did nothing whenever I was on it. I recently took it apart and found the elastomer piece on one side had completely disintegrated. I ordered a new pair of elastomers from
www.suspensionforkparts.com (probably where you found the manual for yours), along with a new fork crown race ring, and the fork now feels like new!