I had 2 flats on my garden trailer, I bought 2 new tires for it from Harbor Freight,put them on and 2 weeks later one went flat, bought 2 new tubes and replaced tube in one of the old tires and put on trailer (had trouble removing old tube,so i used a pair of plyers to pull out tube and tore a hole in tube) Tookthe new & old tire and carefully removed tubes to leak check.....Found BOTH tubes were leaking where the brass angle valve meets the rubber inertube,,bout a pint can of rubber cement and coated the brass & rubber conection with 3 coats of glue,reinstall tubes NO PROBLEMS now i have 2 spare tires and one new spare tube !!!!!