Offroad-Express

I adjusted the back drum brakes out to rise pedal and now the brake pedal travels to the floor but just before that happens there is a pinging noise that I have located to the Load Sensing Proportioning Valve then both the back wheels lock up. I can pump the brakes before using them it raises the pedal then brakes work proper the car is a 93 escudo TD01W do I need to replace it or would bleeding it do anything what should I do? I have bleed the back and front brakes with no difference there is a bleeder valve on the Load Sensing Proportioning Valve.

bleed that point at the valve, then do the wheels again.
that should sort you out