Thank you for giving me more information
Check the brake fluid level, if the level is low, you might have a leak causing air to enter the system.
Now, if the brake fluid level is good and pedal sinks to floor when brakes are applied, you have a bypass in the master cylinder primary piston cup.
When the master cylinder's pistons and/or bore become worn, the pistons won't hold pressure and the brake pedal will gradually sink when the brakes are applied.
Here is what you need to do.
Open the fluid reservoir filer cap, while a helper is applying the brakes, look for strong waves (brake fluid movement in the reservoir)the bypassing on the primary piston is occurring.
If the master cylinder is worn, however, then replacement is recommended.
Sunday, January 24th, 2010 AT 9:36 PM