Why are my brakes hard to stop

Hi Liona,

Generally when something isn't working for me, one of my first questions is, does it have power? In the case of your power brakes, the "power" for the brake booster is vacuum. Since you've eliminated the booster itself by replacing it, if it's still not working, it sounds like it's not getting any power (vacuum).

From Vacuum Booster Diagnostics - Know Your Parts:

Inspect the vacuum hose to the booster for kinks, cracks or other damage. Check vacuum at idle with a vacuum gauge. To test booster function once the reserve is depleted, hold moderate pressure on the brake pedal and start the engine. If the booster is working properly, the pedal will drop slightly.

Unfortunately, the site I'm quoting from isn't coming up for me, but the snippet from Google search results has the basic information. If you have a vacuum gauge, check the vacuum at the booster and compare it to the vacuum where the hose goes into the engine. If there's a difference, then you've probably got a bad hose and that may be all that's needed to fix the problem. However, you can usually tell if a vacuum hose is bad just by examining it. Take it off and check both ends for splits or cracks that could be letting air into the booster and negating the vacuum. Flex the hose and look for tears or holes, especially at bends or any part that rubs on another piece of the engine.