Bled the lines and still no brake pressure

So I had leaky lines right where they connect to the lspv so I replaced the lspv and the brake lines because they were very rotted and corroded. Put new lines and bled and still have very minimal pressure in the system so figured my master was bad. Just replaced it with a new one today and bench bled and re bled lines. Problem still persists. I have no to no pressure on my brakes and I'm not sure why. Any suggestions would help.

 

Valve rear pass rear driver front pass front driver

 

And I'm getting zero air coming out so I know the system is bled.

 

ABS?

 

No abs

 

Did you replace the booster, or just the master cylinder, as stated? If only m/c, was it possibly leaking into the booster? The diaphragm may be bad from fluid contamination.

 

No just the master and the master wasn't where I had a leak I had a leak in the back by the lspv. When I changed the master I didn't see any wetness anywhere around it or in the booster anywhere. When I push the brake pedal it basically just sinks right to the floor still but there is no air in the lines and no fluid leaking anywhere I followed the lines and checked them all today. I don't understand what my problem is

 

Did you bench bleed the master prior to install? I'm not an expert in modern brake masters but I know older models can have air trapped still if it wasn't bench bled first.

 

Yeah I bench bled it till there was no air then did it a few more times just to make sure and there was no air. Also re bled the lines after I installed it. There's no air in the system

 

I've had a pile of problem since I got this truck unfortunately. I will check for vacuum leak at booster drums and inside are new a year ago front haven't been done in at least a year probably more but truck has been sitting.

 

I was thinking maybe a caliper issue too but nothing is leaking from either side

 

Motiv power bleeder.

 

Did you properly adjust the new lspv

 

Install a brake line-lock at each corner and see if the pedal gets firm

 

Buy or fabricate a test gauge, and start at the master and work back. You should have >1000psi at the master. If it's significantly less, than the problem is with the master; if it's got good pressure at the master, check the lines to each caliper/wheel cylinder, working in the opposite order they were bled.

 

Your pedal even with pumping never gets hard??

First are your rear Brakes adjusted correct ? Pedal travel caused by excess travel of the wheel cylinders moving the shoes to meet the drums.

Just how are you bleeding the brakes Power booster , Vacuum or by hand?

Quite possible to be drawing in air and not leaking Fluid.

 

No my pedal gets hard if I pump it up but if I do that and hold it it slowly sinks to the floor

 

Sounds like a failed master to me.

 

I thought so to so I just put a new one in and same problem.

 

Have you done pressure checks on the various components?