oh crap, no brakes!

[flatblack60]

so, the other day my brake pedal was feeling a little low/spongy so i pulled over checked the res. and everything looked okay. I drove the truck for about 2 more days with a similiar feel but no problems. on the 3rd day on the way up my driveway i lost all pressure and the pedal quickly dropped to the floor. i jabbed for the brakes again and i had pressure. curious. ignoring my instincts i continued to work only to lose all pressure again half way there going into a corner. i managed to get it safely stopped and out of the road and cleaned my shorts out. now every time i get into the truck i have fine pedal pressure. All of the days that I had trouble were over 100 degrees outside. could this have affected my brakes so radically? the truck is a 60 with the split master, but the clutch side was blocked off when the engine/tranny were swapped. otherwise its all stock. any ideas? all thoughts would be help. thanks

[Scooter3]

sounds like you might have air in them, try bleeding them, its worth a shot

[flatblack60]

I ended up having to replace the master cylinder and everythings okay now, thanks