There is slight resistance when pushing down the pedal but not much as it goes to the floor.
S10 brake pedal goes to floor when truck is started.
I rebled the lines and the abs unit it has a bleeder fitting same problem.
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.
1998 chevy s10 brake pedal goes to the floor did you put fresh fluid in the master cylinder.
Presumably it is putting the brakes on when this happens.
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.
Kink over the cut ends and pinch them tight with visegrips or something similar ideally braze them shut.
I really think you still have air in the lines.
I then start the truck and the pedal goes to the 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.
Press the pedal if the master cylinder is bad the pedal will still go to the floor.
Now disconnect the two real brake lines on the vehicle from the master cylinder and attach these two short stubs in their place.
To bleed manually start with the bleeder the greatest distance from the master cylinder car running helper pushing down about half way on brake pedal and releasing 3 times on 3rd time holding pedal down to half way depressed point while you.
I pump it several times with the engine running and it makes no difference in feeling.
The pedal still goes to the floor.
I then turn off the engine and the pedal is stiff again.
The work started to repair cracked brake line it does have a booster the right rear brake line was leaking so i replaced it the rear brakes and blead the lines front and rear.
No leaks visable brakes pump up rock hard with the engine off.