My brake pedal has suddenly gone soft, it doesn't go to the floor but it's close. I checked the fluid level, the front the master cylinder was very low. I filled it up, just went for a test drive...no change. Is it what I think it is? Master cylinder time?<br> ???<br>

 

Check and make sure your getting vacuum to your master cylinder. I've never had a master cylinder go out, but I would check your vacuum lines first.

 

Without the vacuum booster, your brakes will push hard. As long as the rest of the system is dry, it's time. Master cylinders usually go quicker than the power boosters. When the booster is going bad a symptom can also be a hissing noise when you push on the pedal.

 

This may sound dumb, but my 93 2wd was doing a similar thing. Brakes seemed to check out okay, turned out to be a front wheel bearing gone. When you applied the brakes, the piston pushed the rotor away and the pedal went almost to floor. Strange thing was, the front end wasn't loose when driving. But if you turned a corner with your foot on the brake, the pedal would come back up. New bearings,spindle, hub and shield later all was well. Just one thing you could check Rick