Sometimes if you pump a few more pumps after the grease starts to appear it will force grease deeper into the joint.
If all the grease appears to be coming out the bottom with each pump, try wrapping a shop rag tightly around the bottom. This will not stop all the grease from coming out but may slow it enough where some will be forced to the top.
I used to stop adding grease the moment a little grease started to exit the joint. An old time mechanic showed me the benefit of adding a few more pumps. A lot more messy and a uses more grease but helps get grease all the way into the joint.
I have found that an air operated grease gun works best for me. I have a rear shackle that acts like it isn't taking grease at all but after about 30 or 40 pumps the grease will start to appear on the back side of the shackle.
Good luck,
Gary: who started his career as a grease monkey.