I posted this a while back but here are some updates...

Ok, about a month ago I purchased a 02 Volvo S80 T-6. I love the thing, but the only problem I keep having has to do with my brakes.

My brake peddle nearly goes to the floor before my brakes grab, as if there was no pressure behind it. I have found if i tap the brakes lightly before begin to brake the brakes are right there, as if they had to build up pressure before I brake. One time, when my brakes nearly when to the floor I had a message pop up saying "Anti-Skid Service Required". The message went away once I turned off and turned back on the car. The message never comes on when I tap the brakes first to build up pressure. Please Help, Could this be as simple as air in the brake system (By the way, Brake fluid is full, and no fluid loss what so ever) or could this be something more serious?

Updates...
I purchased a new "brake switch" A plastic piece that has 3 hoses and an electrical connection running to it. One hose goes to the engine. Another to an "air pump", (I guess that creates more vacuum when the engine doesn't make enough due to the turbo.) The last goes to the Brake booster... I replaced this because I thought maybe the switch was bad and it wasn't telling the "air pump" to turn on at the right times making the brakes soft due to lack of vacuum. Well I still have the problem above. It does happen less often and the brakes are some what soft. If I turn off the car and pump up the brakes then don't get rock hard like in most cars. I think my next step is to have the brakes bled... If you have any suggestions please let me know!!! thanks!

 

I would say bleed the brakes it really sounds like air in the system.

 

Check for a vaccume leak ......Tech is right blead them but make sure you dont push the pedle to the floor you may ruin your master cylinder.

 

according to this statement.. " My brake peddle nearly goes to the floor before my brakes grab, as if there was no pressure behind it. I have found if i tap the brakes lightly before begin to brake the brakes are right there, as if they had to build up pressure before I brake.... " it sounds to me like you may already have a problem with your master cylinder. sounds like there is fluid seeping past the o-rings in the cylinder under low pressure apps., then when you tap the pedal the brake is right there, temporarily making a proper seal. if bleeding the brakes does nothing thats the next thing id check...