Hi, I have a 98 chevy ext cab pick 2wd ...My question is does anyone know how i can check or get air out of my abs unit..I have changed the master cylinder, front calipers brand new brake shoes and rotors , brand new back brakes..new drums and pads and has been bled all around. But i still have a spongy pedal that goes all the way to the floor when I slam on my brakes to stop quickly if i had too..

 

Did you bench bleed the master cylinder?
If not, you will have to take a longer bleeding process at each wheel cylinder.
Old fashion way, pump up, and hold the brake pedale down while a friend bleeds off the right rear cylinder till the pedal hits floorboard, DO NOT RELEASE THE PEDAL TILL THE BLEEDER VALVE IS CLOSED! Rotate the wheels with bleeder valves with that procedure till you get a "full pedal". You should also since you replaced the back shoes, make sure they are adjusted outward to the drums.

 

You need to start at the wheel furthermost from the master cylinder and work your way back to the wheel closest to the master cylinder.

1. Passenger side rear.
2. Driver side rear.
3. Passenger side front.
4. Driver side front.

I suggest that you keep bleeding each wheel until you get clean fluid coming out. As long as you are doing that much work you might as well flush the entire brake system.