Bearing Buddy - Greasing Problems

I went to put a little grease in the fitting on my new trailer before a long trip that I was going to take. I snapped the grease gun fitting on the bearing buddy fitting, but could not get it back off after I had pumped a little grease in it. Finally I gave a yank and the whole fitting came off of the inner wheel. OMG!!! I got it off with a vise grips and faired it back smooth as best I could and snapped it back in, but now I think that damage has been done and I need to replace the whole bearing buddy. What went wrong here? I certainly don't want to put grease in again - could it be my new grease gun was defective???

 

Yea, that is the conclusion that I have come to, but I am still wondering why I could not get the grease gun off of it. Needless to say, I will be getting another grease gun as maybe the tip was defective (?).

 

Thanks for all of your help! I actually went to ACE hardware today and they were helpful, as usual. They got one of their new grease guns off of the shelf, and then a fitting (I think they call it a zerk, or something like that) and snapped the grease gun fitting onto it. THEY COULDN'T GET IT OFF ALSO!!! They had to put it into a vise to get it off! I got home and called the trailer manufacturer (Tennessee Trailer) who was very helpful. I talked to someone there that got all of the information and their Plant Manager called me back. He said that I should find a grease gun that is not a cheap one like from Wal Mart or someplace like that (I got mine from BASS) as he said the heads just snap on and can require a "yank" to get it off, which can pull out the sensitive parts of a bearing buddy. He said to look for a gun the has a head that you can pull back and release the fitting and that will not damage the bearing buddy. He also cautioned about overfilling the hub, as that can lead to problems also. He ended up by saying that he would ship me new parts, free of charge, to replace those damaged. Now that's the type of manufacturer that one should give their business. If anyone does know where I can get a gun with the head like he described, I am in the market!