Perfectly normal!! This unit varies the pulse to achieve "proportional" action.....Completely worthless for attempting to partially set your brakes in the air for a short roll out upon landing....Whether you meant to or not!!!

You should really look into splitting your pnuematic systems like I and many others do. Run one system for your gear only and the other to operate your wheel and speed brakes. It seems that the wheel brake systems are more prone to get problematic concerning leaks than the retracts. I guess you found this out the hard way...

Kevin