I'm not familiar with hydro-boosts, don't know much about diesels. Is this a brake booster, or is it used for some other function?

As for being inventive, that's why I'm here, I've come up with a few ideas, but this will be my daily back-and-forth to work car, so I don't really want to give up my glove box or do any thing that's hard to reach or service. I'm aware of the small booster setups, but don't have the funds for that right now. Thanks for the suggestions, and I'll be waiting to hear what a hydro-boost is. I live in a town of about 75 people, so it's not a hot-bed of rod building.