Chevy & GMC Vans

My 1993 AWD Astro's brake system seems like it is getting hard to brake. It takes a lot of foot pressure to apply the brakes. The van won't lock up the brakes or ever need to apply anti-lock either. The power steering is working fine so I assume the power steering pump is working. There are no warning lights on the dash for brakes or ABS problems. I am suspecting maybe problems in with the hydro boost brake booster.

What symptoms do hydro boosters have going when bad? Can they fail without leaking? Is there a test for the hyrdo boost to know its working? Any I ideas what else to look for with hard brake symptoms?

Something else to note this van has around 110,000 miles & the brake and steering systems are still original including the fluids. The brake & power steering fluids seem pretty dark in color from age. Can hard braking be caused by old dirty fluids?

Hi All,

There is a great You Tube Video on Astro Hydro Boost replacement. The Video was made about 6 years ago by Eric the Car Guy.

He does a great job showing the entire process.

I was so impressed I will tackle this job myself on my 2003 AWD with hydro boost.

The hydro boost system uses power steering pump to create high pressure to store pressurized gas in the accumulator . A check valve is opened when the brake pedal is pushed allowing some of the gas pressure to move a piston in the hydro boost that is the Power Brake assist. The Astros with hydro boost do not have the traditional vacuum diaphragm power brake system.

AP