if you sprung a leak bad enough for your pedal to go all the way to the floor you should be able to see it. especially if theres fluid in the master, pump it a few times and you should have a 2 inch puddle on the ground. its possible the master just failed. worked on a jeep the other day, same symptoms, barely had any brakes to even pull it into the shop. no leaks at all.

on the jeep though it actually blew out the back of the master and filled up the brake booster with fluid.

so without seeing it i would say master, thats been the problem everytime i ever ran into this

 

That would make sense and explain why i am not seeing a leak. Would fluid leaking into the booster cause damage to it? Should i overhaul the mc or just replace it?

 

Good news! Replaced bad proportioning valve! Bled the lines. Brake pressure! Total investment around $40! $25 for m.c.( not needed but now i have spare) and prop valve. $15 for fluid and misc. Thanks everyone for the help!

 

I wonder what made the centering valve trip... Oh well, got lucky on this one, cheap fix! Glad you got a pedal now!

 

interesting. i have never seen a prop valve fail ever. seen them get nice and crusified and start leaking but never cause brake issues. good find

 

In 40 years of working in shops, I remember replacing one. The vehicle had a rusted out brake line, that tripped the valve, and it set for several years without being driven. As a result, the centering valve corroded and seized up. As important as the prop valve is, they usually engineer them with an element of overkill.