Brake pressure valve?

[05chevy]

I was wondering if anyone has messed around with the pressure releaf valves on the master cylinder or brake calipers? I can't get my truck.to hold any more then 14psi at the line. I know old school racer have done this before in the gas world. Wondering if anyone here has messed around with it on our trucks?

 

[Chevy1925]

I was wondering if anyone has messed around with the pressure releaf valves on the master cylinder or brake calipers? I can't get my truck.to hold any more then 14psi at the line. I know old school racer have done this before in the gas world. Wondering if anyone here has messed around with it on our trucks?

there is no pressure relief valve on the calipers or master cylinder that i am aware of. You mihght try changing the brake fluid out with new stuff if you have not done so. id also flush the powersteering fluid and make sure your brake pads are sliding properly on the slides (they rust up easy).