I've always used the smaller grease guns using only lithium grease up till today. I decided I wanted to try moly enhanced grease, Vavoline Synpower synthetic grease actually, so I had to buy a 14oz grease gun. I'm also having to use a needle. I've a used a needle on the smaller version with no problems, but with this one I can't seem to get it to work more than two minutes without having to go through the air removal process. I bought it at Advance auto. Did I just get a bad one or is it just me. Any pointers, Thanks.