A problem with the the power steering pump will affect the Hydro boost unit and will cause no brakes-
FLUID LEVEL CHECK
To check fluid level, run engine until power steering fluid reaches normal operating temperature, about 170 F (77 C). Turn engine off. Remove fluid reservoir cap, and check level gauge. On models with remote reservoir, fluid level should be 1/2"-1" from top of reservoir with wheels turned fully left. Add fluid through fluid reservoir cap as necessary, and recheck fluid level. DO NOT overfill system.
HYDRAULIC SYSTEM BLEEDING
Fill reservoir to correct level. Allow fluid to settle for no less than 2 minutes. Start engine and run for 30-60 seconds, then turn off. Check fluid level and add fluid (as necessary). Repeat procedure until fluid level in reservoir remains constant.
Raise and support vehicle with both front wheels off ground. Start engine. Turn wheels right and left, lightly contacting stops. Check fluid level and add fluid (as necessary).
Lower vehicle. Turn wheels right and left, slowly from lock to lock. Turn off engine. Check fluid level and add fluid (as necessary). If fluid is foamy, allow vehicle to sit for a few minutes and repeat bleeding procedure.