I just had an invisbrake installed in my 2011 Honda Fit, they intalled it in the hatch area on the side.
I have read with great interest about vacuum leaks. I have notice the Invisbrake does not hold the 40 lbs it is set at, it seems to work ok, when brakes are applied it pumps up and applys the brakes, but after setting a while the pressure is gone and the brake pedal seems hard. Seems something is leaking down sometimes it holds the pressure longer then other times.
From what I am reading here the box may have a defect with a short hose leaking.
Guess I will be calling Roadmaster, or is there a simple fix I can take care of?