Bi-directional door stuck

[Cajun83HO]

The dual diaphram door by the gas pedal constantly blows to my feet. It only moves slightly when vacuum is present. Looks like it may be stuck. I know I have vacuum. Even used a vacuum pump at 15". But it doesn't change. I think it should rotate 90* but it looks more like 15*.
How in the hell do I service the thing?
Remove dash and inside ac box?🍺🥴

 

[Cajun83HO]

Hello, has anybody had to replace this valve? Is there a common problem /fix?
Air constantly blows to floor. It should direct air up to either defrost or middle.