Last year I noticed our '54 To-30 wasn't braking well, and I discovered that the left rear axle seal went bad, so over the summer I pulled the axles and replaced both the left and the right seals. Then yesterday, I while mowing, I noticed the brake pedal didn't work to well, so when I finished mowing, I looked in the brake adjuster hole, and thought I noticed a drop of grease inside, so I am assuming it went bad again. Any idea what would cause it to leak after about 30-50 hours of use? I put on the NAPA seal. Is there a better one that I should use?