ok my brakes keep cycling from a very easy to press pedal to a harder to press pedal...i can cruise on the highway i pull off the highway to a rest center and my brakes have a very soft pedal very easy to push to the floor...then i'll drive again and first time i pull over they are much much harder....if i get going when they are harder i will get a vibration cause they won't unlock...if i pull up on the brake pedal it will almost always go away (but the pedal has no free travel in it..i mean it is adjusted well under there ..odd)...what gives???....this has started happening ever since i changed my bad booster...i had d/c the master cylinder and swung it out of the way to get the booster in...the master cylinder was tilted to almost 90 degrees...i never bled it it ...calipers, pads, shoes are new...and shoes are perfectly adjusted

i was thinking...

1) i need to bleed it all the way from the master cylinder and on...I have 4 wheel abs..what do i have to bleed?
2) i have a bad master cylinder?

help me guys

 

when i'll bleed the brakes tommorow...can i bleed the master cylinder and then proceed to the rears and then fronts? or do i have to bleed at every component from the master cylinder on?

or

if i have air in the master cylinder, can i get it out just by bleeding the 4 wheels like we always do?

 

You'll need to bench bleed the master cylinder, then progress to the right rear, left rear, right front, left front. try that first but i think the problem is the booster adjustment. did you get a used one of a new one those are a pain to get adjusted right and are very touchy. But i think the problem lies in your booster rod adjustment. PM me if you have any ?'s.

Chris