Zero Turn Mowers

I have a MZ5225 and need to know how to adjust the parking brake. I purchased this mower on 6-9-12. I noticed that one wheel is free wheeling when the parking brake is set. I saw that there is an adjustment bolt. I checked the manual and there was nothing in that book on how to adjust the brake. the wheel that has the parking break set correctly can I measure the compressed spring and set the other wheel to that measurement. i have grass coming the throught the deck as if a weld is missing to prevent this. its on the vertical part of the deck at the top where the vertical and horizontal meet. its on the curved sides of the deck. I have incerted a picture.