Hi Scotty, I have a ford Ikon 1.3 2005 petrol car. it ran about nearly 50,000 KM. As part of maintenance I've taken out the intake manifold and cleaned in a soapy water solution and reinstalled on the car. In this process i had to remove brake vacuum hose from the booster because i 'm failed in detaching the vacuum hose from intake manifold side. i prevented the check valve from dipping in the soapy solution. so its still good i believe.

So what is happening when i apply brake is the pedal has no resistance at all . i can use my finger to push the pedal to the floor and when i turn of engine the resistance comes back.I did following tests to make sure brake booster and other components are working correctly.

  1. filled the brake reservoir using new fluid to max level.
  2. checked the vacuum on brake vacuum hose - Result : good suction.
  3. Started the car for 1 min then turned off. Pressed the pedal 3 times , Result : brake pedal get hardened.
  4. As the pedal got hard from 3rd test i started the car, Result : Brake pedal sink all the way down to floor ( no resistance at all )
  5. i checked all wheels for fluid leakage, All good. Also checked reservoir fluid level , showing same as before.
  6. On inspection i am able to find some old leakage marks on master cylinder ( pealed out paint ) but not able to see any fresh oil on these marks.

Please help me find out which component is faulty .

I believe one more thing to check that is one way check-valve by blowing air in opposite direction for that i have to remove hose from intake manifold. On my car its hard fitted ( not coming off ) please guide me how to remove it. Attaching

pic. thank you.