So my brakes allmost got me killed the other day.I recently rebuilt the rear brakes&swapped new pads in on the front&they seemed fine but the othet nite I got off the hwy&a lady jumped out infront of me&I slammed on my brakes&had none.
Well I checked & my reservoir & the part for the front was empty & the rubber gasket was sucked in.I filled thought was fine. I bled the brakes & started the truck drove down the rd slammed on brakes &had none pumped a few times then they worked.It seems like everytime I start it unless I pump I dont have brakes.Wtf is going on?I noticed betweeen the booster & reservoir its wet looks like maybe a leak so Im thinking its the booster plus when I pump I can hear air everytime I pump it sounds like its sucking.

 

Sounds like a leaky master cylinder and/or brake booster. I'd also check your metal brake lines to ensure that they are not leaking, too. The brake lines tend to rust out over the years.

 

if the fluid is leaking out at the master cylinder, it points to a bad master cylinder, leaking around the push rod. there should not be any fluid anywhere in the booster, or anywhere outside the high pressure lines of the brake system.

you could rebuild it, or just replace it with a new/rebuilt unit. be sure and do the bench bleed process before installing to save a lot of time bleeding out the air.

edit- AD beat me to it.