maybe it is that the button head fitting is partially blocked. grease oozes out but doesn't squirt out. it's a nice shiny fitting but has been sitting and who knows what's inside. rather than mess with it i'm going to get a new one and see if that was the problem. i have 0 grease in the gun.

What I've done with an old grease blockage is pull the Zerk/Button-Head heat one end of a piece of tie-wire or #9 wire red hot and stuff it up in the hardened grease - rinse and repeat if needed.

the new button head fitting came today and it has a black rubber in the center that the old one doesn't have. I don't know if the old one is a different design or missing the rubber.
anyway I pumped away with the new one and I can't tell if anything is going in. there's grease in the gun as it comes out when not on the button. How many pumps with a hand gun with a lever would you say it would take to fill a roller if the roller was empty? I have no idea when or if they were serviced previously, but 300 pumps seems excessive.  

thes seals maybe gone. or the damn thing is bone dry or more likley the fitting is blocked

My guess is it is bone dry.

that looks normal. if it was blocked you wouldn't be able to pump the gun. my guess is that the seals are blown in your rollers and the grease is escaping where you can't see it. my rollers will usually take about 3 pumps before i feel resistance from the seal. on the rollers that i have with bad seals you can pump till the cows come home. i usually give the ones with bad seals about 10 pumps so i can expel dirt with the grease. i use corn head grease.

Remember that the normal track greaser is high volume low pressure. A normal grease gun is low volume high pressure. It takes many pumps to equal one pump of a track greaser.

My first machine shop job in the late seventies; I made thousands of those. Boss was an a hXXX and would never give me just one to keep for a souvenir. That was long before I even had a tractor to grease with one.

The volume pump won't fit on the upper roller of my d2, I have a small button head on the upper roller. I just filled an old grease tube with the 00 grease and used a regular grease gun. I remember it took a lot of pumps and I think I had to refill once to get that small upper roller filled. I've pumped my fair share of grease and if you pay attention you can feel when things are full

thanks to all for the suggestions. I'll tackle it again this weekend when the weather is nicer.
I don't see any grease leaking anywhere and i'm dealing with 2 machines, a nice 9U and a 4R, and all the many button heads act (or don';t act) the same.