Do yourself a favor since the liner is 6 yrs. old . Replace it ! I replace mine after 3 yrs w/ similar problem . The warranty's are useles as far as how long those things are supposed to last anyway - as far as I am concerned . With reservation , I decided to do it myself for the first time w/ help from only the wife . It ended up working fairly well . Just make sure when you take the old one off , get on your hands and knees and get out as much of the garbage affecting your liner floor . You would be surprised how much works it's way up thru that sand that is sharp , especially after 6 years . At least that is my opinion .
I know a guy who lost 2 liners over 3 years , causing damage to both his and a neighbors garage , plus the neighbors basement . Is it worth the trouble ? Will repairing eliminate the Underlying Problem ? Probably not . I too live in Chicago . Good Luck.