I have had a problem with my brakes already for some time. The garage in the Eastern part of Russia (where I live) has diagnosed it as a brake master cylinder failure and said it needed to be replaced. However, I was not entirely convinced with their diagnose as it took some tries to have them look at it and finally after a test run they said to change the brake master cylinder. Now, as these are quite expensive parts, I would like to ask if anybody can tell me if I should change the brake master cylinder (USD900), brake booster (USD800) or the both of them (USD1600). Symptoms:
- when I start the car in the morning, the brake pedal goes down and comes back up; but there are other times where it doesn't do that (pedal stays where it is);
- after releasing the brakes it feels like the pads stick to the discs for a second;
- sometimes when applying the brakes there is a hiss and sometimes not;
- there is sufficient braking power and never have the feeling that there is any loss;
- visual inspection doesn't show any fluid leakage on the unit or under the car;
- brake pedal very slowly sinks when having a foot on the pedal and applying lot of force but not always (sometimes it feels quite hard
