97 f150 brake pedal is hard to press during winter, and takes forever to stop truck...Dangerously slow stopping. It's soft during the summer and warm weather, but often goes all the way to the floor.... Sometimes locks up randomly, but mostly when it's raining.

Do you think it's the brake booster, the master cylinder, or perhaps a vaccuume issue?

Love the channel Scotty. My friends and I often play your videos in the shop with the audio broadcast over the speaker sytem when we are working on our projects.

Thanks for the help over the years.

often a bad booster does that, or a bad master cylinder. Masters are much cheaper

Thank you. I pulled the valve off of the booster today while the truck was running and it had good suction/vacuum. The brakes have responded much softer since then, I'm thinking vacuum wasn't the issue. Guess my next step will be to change the master cylinder and cross my fingers.