Ok 94 gc 5.2 been driving fine got up this morning had no brake pedal. Bled all 4 brakes again and no air in the lines. Still no pedal. I'm guessing its the master cylinder. How do u bleed the master cylinder once I change it? Or does it seem like another problem

 

I read about bench bleading somewhere for the master

 

If u think you have air in the master cylinder you need to crack the lines by the master and do the losen line, step on pedal to floor, close line, and release pedal method. But if your pedal sinks to the floor out of no where then u probably need a master

 

Check and see that you haven't turned the seals inside. To do this, have someone pump the pedal whilst you overlook the Resevoir. If you see bubbles in the resevoir then your master cylinder is US (Pardon the pun) and needs replaced.

 

Make sure you dont have a leak in the line anywhere I know that happened to my gfs car

 

The pedal doesn't sink out of no where when u go to brake there is like no resistance it just goes to the floor. And there isn't air in the lines I bled each caliper today already and if thee was a hole in the line air would leak in. And I will try to loosen the lines and see if that works. Thanks for the advice. Any more anyone has would be appreciated as well. Best to know all my options

 

Bad mc?

 

x2 on the Master Cylinder. If you step on the Pedal and there is no resistance while sinking to the floor, your MC has bad primary and secondary seals and the fluid is getting by the pistons. This means that the effort you exert by stepping on the pedal is not being transmitted to the calipers via the brake fluid.

They do sell rebuild kits if your feeling up to it, but it is easier and less headaches to install a new one. Better peace of mind to IMHO.

 

Ok thanks alot

 

Ok I did the take the line off and floor the brake pedal method and didn't work and there was no bubbles in the resivoir when I pump the brakes... Guess I gotta change it out.

 

Highly doubt you suddenly got air in the line so bench bleeding it is useless. MCs are dirt cheap so just swap it out

 

X2, just replace it and be done with it.

 

It was the master cylinder its fixed thanks everyone.

 

How much did that set you back?