Hydrovacs tend to be a little difficult to repair, but they are available as rebuilt units in most cases. Once that's functional, you'll really like how the brakes work. Just be patient and have plenty of brake fluid on hand when it comes time to bleed the system.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!