There might be a slight problem with that method. Ok you map control Key + X axis (aileron) to wheel brake axis, as soon as you press that control key, the brake will be on at 50% if your centering you plane to land on the runway (i.e., the x axis runs -1 to 1). That much brake is a bit high and might cause some problems on landing.
Anyway, if that doesn't work for you, I or someone can write up a script for you that does that specifically (i.e., increase pressure at 10% increments, turn off after you hold it down for say 3 seconds). But if you don't have any real axis, you need to install PPJOY and create virtual joystick and put that virtual axis in the confUser.ini. Then you write the script to send the output from the key you choose to press to that axis. So, you press the key, the value goes from -1 to .8 to .6 ...etc. after 10 times its at 1. you hold it down three seconds and value goes to -1 (output 0).
Or, just wait until developers add it.
