Hello.  I have a Chevy Trailblazer 4x4 Auto 2005 Ext 4.2ltr. 105.000 miles. The Vehicle is in Cebu Philippines. My problem is the brakes work perfect when I start my journey. but then at any point during the journey the brake pedal goes to the floor. I can just about stop the vehicle. If I keep on driving the brakes will return and work perfect again. some times working for many stop and starts. other times will Fail again soon after. we have changed the Pads and can't find any leaks. I have no idea what the problem is. The vehicle has developed electrical problems. every time I hit a bump all the light on the dashboard light up. I know the Clusters need changing. But I am reluctant to spend out if the Brake problem can not be resolved. The Chevy Garage only interested in New Vehicles. Parts I have to order in USA. Local Mechanics say it could be many things. The engine and transmission work Okay. Your help and advice would be very much appreciate. If you cant help  I will sadly scrap the Vehicle 

kind regards