is this OK (open; close)?
or reverse (close; open)?

 

What is it exactly you are trying to ask? More info on your question might help .

 

this valve block break fluid. how to open manualy? is this good direction (open, close) shown in attach?

 

i think its made for sensing when the rear has the weight of 3 people and or the trunk is full of heavy items or towing a trailer,towing a jetski(i wish)
so then the wheel\tire outside that picture will lift under weight and pull the small spring closed
which moves the lever under the valve,does it open or close the valve under loads ?i dont know!

why its there? i dont know,im thinking a open valve(load sensed)(or car lowered)
will use the rear brakes first or more-isnt that better for towing?

i did bring this up here years ago in someone elses post
my theory was since i lowered my maxima on 2 inch sprint springs
it would trick the twin load sensor into thinking my cars full or im towing
my brakes were always awesome,all four would lock up on my 91se then the big burnt rubber cloud floats by in front,lol good times