I was on my way home when I was coming to a stop and the break pedal just went to the floor and lost pressure. It would only stop after hitting the floor with the pedal and only the rear wheels. Well, I replaced the master cylinder after inspecting it and noticing some "pieces" in the reservoir. The problem is that after replacing it, it still has no brakes. The pads are all good, there is very little pressure going to the bleeding lines and it won't brake for crap. I tried looking around here but most of the threads are dead end with the same problem but they just stopped posting. The booster is fine and we bled the lines and the MC it self, for 2 hours with about 3 bottles of fluid to make sure we got all the air out. I've heard of the LSVP? or something like that? Can anyone please help before I call salvation army and make a donation?

there are no visible leaks from anywhere under the car and I've followed the brake lines...


Thanks.

 

there is a LSPV (load sensing proportioning valve) located on the passenger side frame rail even with the rear diff (a rod will go from the diff to the valve). It has a bleeder on it that is supposed to be bled as well, but I dont remember the order. If your sure you dont have any leaks, then there must be air in the lines somewhere that is compressing causing the lack of built pressure to actuate the brakes...

I'd start with a bleed at the LSPV, then try capping off sections of the brake system to try and find the cause.

 

Still have the problem. Power bled the whole system and nothing. New MC as well. Selling the thing.