have you repaired the pack before? i find stress points and rub points need attention on my gear- repairs or "pre-pairs"- fixed before the failure- rather than reinforcements. 99% of my repairs are done with glue- choose silicone for silicone coated fabrics, choose aquaseal for urethane coated fabrics. always clean the area with alcohol first!
on the outside of your pack, check all seams and attachment points. pull on the fabric/strap, looking for gapping or pulling in the threads of the fabric. try to simulate the stress the pack gets while it is loaded and being used. put glue in areas that look stressed. you should stuff the pack to expose the area and keep it open while the glue dries. if you think the glue might go thru and stick to the stuffing, put a piece of tape or waxed paper on the back side.
check the exposed threads- esp. where they get rubbed on. on my pack that is the bar-tack areas where the shoulder straps attach. a coating of glue can keep the thread from wearing away and causing a failure.
check the fabric for small holes and worn areas by going into a dark room and putting a flashlight behind the fabric. use a marker or chalk to circle the areas needing repair (make a big circle- well out of the glue zone). this is a real eye-opener! you will find lots of worn spots that look fine in normal light. these are weak areas just waiting for a little stick to poke them- then make a big tear!
turn your pack inside out and inspect the seams and attachment points. glue as needed. if the stitching has failed, sew the area and consider why it failed- modify as needed.
i do a full inspection of my pack and mark the areas that need attention. then i take several glue-days for repairs, since one must allow each repair to cure before changing the pack's position. after the glue has cured, dust the glue with talc or corn starch or chalk or whathaveyou to keep the repair from sticking to itself.
i think once you have done a full inspection, you should know better if the pack is up to your next trip!
