hardinge Dsm-a collet issues.. HELP !

okay i'm the maintenance guy for my company and i've been here about a year. The hardinge i'm talking about is a dsm-a chucker with an automatic 5c collet closer if that sounds wrong its because i'm not a machinist. First of all its gotta be from the early 70's or so and its never been maintained properly so its literally a pile of junk, and they wanna spend as little as possible. Secondly i have the air pressure set accordingly. The collet just will not pull the whole way back to hold the part. i tore the whole head apart on that sucker and put new o rings and all that good stuff. the solenoid has been taken apart cleaned and lubed its doing its job. The only thing i can come up with is that the collet is sprung or damaged. but i have no way of knowing because the actual "lead machinist" tells me it is fine. yeah that was a lot to take in but any help would be appreciated. Thanks. P.S. any info on removing the automatic closer and just installing a manual one would be good too. prices?

Which type of closer does the DSM-A have. Rotating cylinder or manual type with cam/levers and operated by a stationary cylinder?
Obvious things to look for would be a broken or galled up drawbar. Collets are pretty straight forward. Cheap imports sometimes will not open correctly but will usually always tighten. Could be a spacer or something left out and not enough travel on the drawbar to pull the collet closed.

the rotating cylinder type

Lets ask some more questions since I still do not know what the machine looks like. 99.5% of the small Hardinge lathes use a 5C collet. There are a few that use a B&S 21 collet which is a pusher collet instead of the 5C pull type.

Assuming it is a 5C can you put the collet in the spindle with the draw bar removed and push the collet all the way in till the taper tries to close it? If so we can assume the collet key or nothing else in the spindle is stopping the collet from being pulled back.
Next I guess I would check the cylinder for full travel, does the drawbar have free motion back and forth in the spindle. Look for cracks in the drawbar near the collet threads. Spacers in the cylinder or between the draw bar and cylinder could limit travel if incorrectly assembled. You have pulled the drawbar out and cleaned out the inside of the spindle, right?
If it uses a #21 B&S collet I do no even want to try to guess what is wrong.

i will try a few things you have mentioned tomorrow. i appreciate your help i will let you know what i come up with