For a while now the wife's blazer has to be refilled on break fluid, I mean around 2-3 weeks otherwise the front half of reservoir is empty.. I've replaced the master but it still does it.. I can't seem to find out why.. No puddles left anywhere (parked in same spot/area every night) is it being sucked threw vac line on booster n Burned? I want get it fixed before its an issue, have had to bleed the breaks a few times due to not catching it in time and want it fixed before something happenes, thanks in advanced..

 

It may only be leaking when the system is pressurized. Make sure the reservoir is full. Start the truck and pump the brakes. Keep checking the fluid level and follow all the brake lines with a light. I doubt that it's getting into the engine. Unless there's a ton of smoke from the exhaust.

 

Definitely a leak somewhere. Is the red "BRAKE" light illuminated in the instrument cluster with the ignition in the run position? Is the brake pedal low when you apply the brakes? What year and model?