i have a 1998 burban and sometimes when i push the brakes down they dont seem to stop me . its like they are only half working will only slow you down about 10 miles a hour but if you let off and push them down again they work right . but it does not do it all the time only sometimes please help me it is a 1500 chevy suburban 350 vortek motor and a 4l60e tranny

 

Welcome to the forum. Is there any differences in pedal travel and also force required between when it acts up and when it works? When you turn the key on, do the bulb test light the ABS and BRAKE warning indicators?

 

yes there is a difference in the pedal when they dont work the pedal seems to push down real easy and it goes almost to the floor . when i turn the key on the ab light comes on like it should and the brake light does too

 

Have you checked the fluid? Is the level proper? Is it brown/milky and dirty? Is there a puddle of break fluid under your truck?

 

Also check your rear brakes.It seems on these vehicles the emergency brake is the adjuster for the back brakes. If you don't use the emergency brake the back brakes don't get adjusted.I'm assuming you've checked you front brakes out already.

 

yes i have checked all of them and they are good ( less than 2 months old but i check them anyways but it did it befor i changed them an still is doing it ) the e brake works really good too . the break fluid is at the proper level it has me confused i dont even dare to drive it no more because you never know when it is going to mess up !

 

could it be the master cyclinder going bad ? or something to do with that darn abs ? or the brake boster

 

You changed the front brake pads? If you pushed the old fluid from the caliper back into the system like usually done, you might have crud keeping the ABS dump/isolation valves from closing fully. The ABS self-diagnostics were pretty crude in those days and thus the ABS warning light is useless in those cases. Consider taking it in for service.

 

I would suspect the Master cylinder and or the booster...

 

Bleed the system again, check the gasket on the master cylinder cap for wear, and check the booster for vacuum leaks.