so i have this really stiff brake pedal feeling when i'm under boost. I'm still using my NA brake booster and lines. i've come to find out that there is supposed to be a check valve to stop this from happening on turbo'd cars. How would i go about fixing this? just buy any check valve and install it or what?

my 93 L hose had a check valve in it your may have died?

i would just make a junk yard run up to aarons (if i lived in tacoma) and find a replacement ..

my hose is definitely bare, plain hose. I'll make that run up to aaron's.