There should be no adjustment to the power booster. Is this your question? There should be a one-way valve that fits in the vacuum hose that connects the booster to the engine manifold. There are no field adjustable parts in the booster.

To replace the booster, most vehicles have clearance issues with the brake line plumbing. If you have to remove the booster and master cylinder together, you'll have to detach whatever brake line fittings, reassemble and bleed the brake hydraulics. <img src="/forums/images/graemlins/kewl.gif" alt="" />

1987 Raider - Roxy
1988 Mighty Max 2.6L Turbo - Pearl
1997 Mountaineer V8 - Freddy
2000 Excursion V10 - Freya