What causes you to SUDDENLY, lose braking power? Porsche MC...
 

What causes you to lose braking power SUDDENLY???

Situation:

Somebody jumped out in front of me, I slammed on the brakes, and it was braking hard as usual, then I feel a pedal bump/feedback for a second, then the pedal just goes to the floor.

I pull over a couple miles down the road onto some WHITE gas station pavement, and let the car sit for awhile...about 30 minutes, as the beach access we wanted to goto was accross from the gas station anyhow...the road is pretty much a two lane backroad, so braking it's how I went a couple miles with no brakes. It's just that, somebody jumped into the road...

No puddles. No wet looking wheels. Fluid resivoir still has all it's fluid. Only, there's no braking power. I pumped the pedal like 65 million times, including driving it down backroads...there's no fluids on anywhere still, and my resivoir is still full....

What could it be?

I'm guessing it could be the master cylinder out, considering there's no puddles anywhere, but don't those usually go out over time, not just in a one time incident like mine???

I have a 944T master cylinder, in my boxes with other Porsche brake parts, waiting for my Porsche conversion to actually be complete. What do I need to do to put it on? I was told that there's no brake switch on the 944T MC, so I'de need to get a brass T, and buy a generic brake switch (they have universal brake switches???), then just put it in there so my brake lights light up...is that all that's required???

Is the mechanical lever for the master cylinder still intact? In other words, did the linkage between the pedal to the pushrod break?

Unsure...I have been drigin it around and when the pedal is completely to the floor, the little red light on the dash lights up. It slows down, very weakly, but nothing I'de go driving anywhere with other than to the 7eleven down the road.....I'll pull up my eBrake and it slows down faster than it does with just the pedal....

When the pedal is coming back, you hear a little suction "squeek"... Like if you were to pull on a syringe needle really fast....been weeks, still no puddles, lol.

I'm no expert, but it sounds like your master cylinder has let go. is there a way for you to pressure test it? do the brake lights work? ( i am not sure how much pressure it takes to activate them, but it's a sign.)

Brake lights do work....the pedal has to be all the way down (when the little red light comes on on the dash) for them to come on though....which is the time, when the brakes weakly engage...about enough pressure to stop you in a parking lot coasting around...

It's getting diassembled today....a new new MC being put on....hopefully it's the fix. I'm just used to MCs going out over time, not just at once...ghey...

Master Cylinder
 

Dude the exact same thing happened to me a couple of years ago but it was a beetle master cylinder and it needed to be replaced.
You have checked for leaks as you say there are no puddles so its worth checking out the cylinder.

Well, it was the master cylinder.....BUT, turns out the one recieved was also fooked...in that for some reason I had no pressure in the rear wheels, only the front. :confused:

Found there was a line that DID somehow blow for the rear. Although, after it initially blew, it didn't leak anymore because the master cylinder was also blown, hence the reason I lost no fluid, because none was getting pushed to it. It was the one that runs along the tunnel on the drivers side...

So I wait today for another master cylinder to be delivered....yay.

Strange coincidences SUCK ***.