I have a 2001 supercrew 4x4 with a soft brake issue. They seem soft and the pedal now goes to the floor. I changed the master cyl and bled the brakes I was sure that was it. But when I back it out it did it again. what's next?

 

Are you leaking fluid? Change the brakes recently? Does the truck have decreased breaking power?

 

No fluid loss that I can tell. And the brakes were just bled and the pads are good. Just started one day out of the blue.

 

After three years of service, the average boiling point of the brake fluid could have dropped to a potentially dangerous level because of moisture contamination. When the fluid boils, it leaves pockets in the line that will cause the pedal to hit the floor. Looks like your truck is a 2001, so it may be time to change that fluid if you have not done it before. That may solve your issue.