I bought a gasket kit for my SM420. There was only a couple of gaskets in the kit - one for the side cover and one for the top. I took the side cover off and was glad I did as I found sludge that didn't drain out. I had to scoop it out. With the cover off, you can get to the magnet and clean the shavings off. I believe I refilled it with 80 wt.
