99 Chevy Tahoe Brake Problems

[priceless]

99 Chevy Tahoe - old body style ? – Police package
Replaced pads front and rear
new master cylinder – bench bled (only bubbles came out of small reservoir
new front calipers
new rear brake cylinders
Have bled the brakes still not right
Problem is seems not to be as firm and will go down
to almost the floor like spongy feeling yet was told maybe still air in lines or
the rear cylinders might need to be adjusted again
was thinking also does antilock brakes play any part in this
read somewhere can get air bubbles there and might need to take
to a shop and do a machine bled

Had a friend come over today and
as she pumped the brakes slowly
air bubbles ( I'm told its called hydraulic pressure not bubbles) came up on the front small brake reservoir
none no bubbles (hydraulic pressure) in back big reservoir
called the mechanic he said
that when he bench bleed the master cylinder no air bubbles in the back big one at all only in the front small one was there air bubbles when he was bench bleeding it
could it be a defective master cylinder ?
No way to be spending my vacation at home - Please help
any ideas sure would help
Thanks in advanced - Linda

 

[stkr]

I have the same package. The brakes just suck. I have bled them repeatedly and put stainless steel lines on. Still awful! Can convert to hydroboost but can get a little complicated. Search on here for hydroboost conversion. Someone had a good post a few years ago.