The brakes are weak.
This situation is generally the supply pressure of the transmission pipeline to show the loss caused by this time should check the brake total pump vacuum booster skin and engine interface is loose or cracked and so on.
When you find that you're on the brakes and you don't have your own itinerary and the pedal position is high and hard, you should consider whether the one-way valve in the vacuum tank of the braking booster system is broken, and the processing method can be changed with the accessory. Second, it may be the vacuum tank to the brake total pump booster in the middle of the pipeline has a rip or brake booster itself problems.
This phenomenon drivers can obviously feel the braking power weakening, the first consideration is whether the pump, the total pump pressure is insufficient, leakage, followed by the brake failure, there is a situation is the brake pipe leakage into the air, if a few feet on the brake pedal height has increased and elastic, then it is likely that this fault.
Brake offset is also known as "bias brake", by the braking system left and right parts of the pump on the brake force is not caused. This situation in the car when the difference is more obvious, the fast side of the wheel first stopped, the steering wheel will be deflected, for this situation may need to replace the pump.