The seal can leak from two spots. If it leaks around the shaft, then it can't be cemented 'cuz the shaft has to turn. If it leaks around the outer edge where the seal meets the cavity, then J-B Weld like I did should do the job. You'd have to get it really clean. You can't use carb cleaner or alcohol with J-B Weld. You have to clean and prep with acetone.
Mark