When you have a pump for years, what happens usually is the rubber bands inside get dry and the pumping becomes hard and requires more effort. Your options are limited because the usual lubricants are not very friendly to the rubber material inside the pump. So, what could I use to restore the smooth action in my very old pumps (both with broken and replaced handles) ? A good solution would be a water-based lubricant, but I don’t have one in my house. I did have some butter though! I covered the rubber inside with some butter and now both pumps work smooth as new!