harp54

Thanks Wolfe 10 I wondered if it is a vacum pump or a pressure pump, seems to be both. I notice that it would not pump up above 20 lbs Then when off it would go down. I check some of the connections by pulling the rear seat forward all seemed ok, I dropped the seat back in position and it tested again. the pressure gauge went to 40 as set, so I am on a hunt for a loose something. If it is leaking down from within the control box would that allow the system to loose vacum? I plan to pull the cover off the box for a look see, any info on this reported short hose? And if so what is the fix going back to camping world is a 2 hour drive one way.

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?