Scored an official copy of the Bendix manual 'Servicing the Bendix Hydrovac' on e-bay. Its a 1943 edition and covers the first and second series hydrovacs in detail. LOTS of great assembly pics and detailed testing equipment.
It Form No 9-227 with correction for the push rod guage. SWEET.
Will scan it in when I get time. Will go NICELY with the TM9-8651 (Jan 1956) TM that covers all three 'vacs plus the air pak.