If it is full capacity then there is no leak.
Engine running brake pedal goes to floor.
The leak may coming from a brake line or one of the brake calipers.
Hold the pedal depressed for 30 seconds.
As you press the brake pedal a valve in the servo opens to allow the vacuum to pull against the diaphragm in the servo to assist you.
Brake lines brake calipers check.
Go to step 3.
Depress the brake pedal and start the engine.
If a valve is stuck open it will keep sucking until the pedal goes to the floor and will only release once the engine has stopped.
Technically there are two main causes that would make the brake pedal sink all the way to the floor.
A common example is you might find the brake pedal goes to floor but still works.
One of the reasons is the brake system loses pressure from an external brake fluid leak.
3 hoses lines pads ok 4 replaced power brake booster check valve and filter.
1 leak from brake line or brake caliper.
1 no fluid leaks 2 changed master cylinder bled system several times.
If your brake pedal sinks all the way to the floor when you press there can be many possible culprits for this problem.
The most common reason this happens is because you have a leak in one of your lines.
Go to step 2.
I have a nice firm brake pedal when the car is not running as soon as i start the engine the pedal goes almost to floor.
But worry not this maintenance guide will give you the steps to troubleshoot and fix this issue of brake pedal goes to floor in under 45 minutes.
Another common reason why your brake pedal may go down to the floor is because you are running low on brake fluid.
When you are ready to leave for work after your car has sat for a prolonged period of time check the ground underneath your car for puddles.
If the pedal goes down slightly the booster is in good condition.
When the engine is started the brake pedal goes almost to the floor will not stop car.
5 engine has good vacuum and idle.
The first thought that comes to anyone s mind when brake pedal goes to the floor when engine running is that there is a leakage in any of the brake lines that outflow the pressure in the brake system the first thing you require is to check the brake fluid level.
With the engine stopped depress the brake pedal several times.
With the engine running depress the brake pedal and then stop the engine.
Reasons your brake pedal goes to the floor.
So i ruled out the master cylinder since i just replaced it last week.
