Brake failed driving home -4 degree whether. when i came to first stop light my brake pedal was on the low side(almost the floor). second light 300 yard later, brakes failed (no resistance until the pedal hits the floor, then 0 resistance on the next stroke. 10 mph into the rear of the car in front of me. No sign of fluid from hoses or engine. brake reserv is normal level. is there a fuse or other device other than master cylinder and booster that can cause this?

little low fluid w/no sign of leak is fluid going into calipers from pad wear ---causes of brakes to floor --need brakes replaced--failing master--air in lines--leak--flex line failure--caliper failure

ON LEVEL GROUND
With the transmission selector in "park", start the motor.
With your foot on the brake pedal (steady-constant pressure), move the transmission selector gear to neutral- then turn the 4 X 4 selector knob to 4-wheel drive high. Wait for the 4 X 4 engagement.
Once it is in 4-wheel drive high, with the transmission selector still in neutral, quickly pump the brake peddle twice, keeping you foot on the brake pedal on the second pump, turn the 4 X 4 selector knob from high range to low range. The transfer case should then change from 4-wheel drive high to low.
Electronics being what they are, you sometimes have to repeat the process. You may even have to inch forward or backward.
[I have an '01 Excursion and an '05 F250 with 4 X 4 on the fly...I miss my '97 F250 with the manual 4 X 4 shift on-the-floor!]
Anyway, check the fuse panel for any blown fuses.
Double check to make sure that the problem is not just blown 4 X 4 lights on the instrument cluster. With the nob turned to 4-wheel drive, have a second person- a spotter, check to see if the drive shaft to the transfer case is moving. If it isn't, you have to delve into the troubleshooting process.
Check the solenoids, vacuum hoses, vacuum actuator, and transmission range sensor on the transfer case. .

hi have u had achance 2 check brake fluid level it may just be low also with the heating of the floor it may be that the heat sheld is missing.i have a similer problem with my car the carpet ronud the tranz tunnel gets quite hot keep thinking heaters on but pay u to have alook to make sure theres no fire risk

It could mean that ,or it could mean the master cylinder is bad . open hood look at master cylinder drivers side of car by firewall see if it is low on fluod their will be a cap on it add if needed. before driveing away push brake pedal many times hard than check for fluid leeking or master cylinder low again. if still loseing fluid find where it is going report back and will tell you how to fix. hope this was helpful ps. if pedal goes to floor or fluid is leaking dont Drive vehicle.

I believe your pressure plate is broken and at a minimum will have to be replaced along with the clutch disk.

A bad brake master cylinder will cause the pedal to go the floor.

renew the master cylinder immediatly ,the seal between the front and rear chambers has failed. This is a dangerous vehicle and shouldnt be used in this condition it WILL FAIL SOON

Yes sounds like serious problem, especially the harder to stop, If you mean the car just isn't stopping as fast and included with the pedal getting closer to the floor sounds like you have a brake fluid leak. Might be leaking from a line maybe the master cylinder or caliper or wheel cylinder, any which way probably should get checked out.

You have to bleed it on all 4 wheel

My 03 trailblazer does the same thing and the service dept. told me that it was normal for this model to do that, it has never failed to stop but if your sitting at a red light you can feel the peddle go down to almost the floor but it stops fine and it has done this since day 1 and they say thats normal on the trailblazer.