ActiBrake, Internal view.
I'll spare most of the long story on this, but this was a recalled/inspected/passed ActiBrake that I chose not to trust, bought a Carlisle, it later had a hiccup (couple of days before summer trip) and that forced me to re-install the old unit for a trip. It didn't last till we got back home. Fixed Carlisle (thanks Barry @ carlisle) and re-installed.
With a recent thread about converting to disc brakes and the good discussion, decided to cut open old unit, to see internals.
Not much fun.
These are a sealed unit, I had to take an old pruning saw to the case in several spots until it opened up.
Motor and pump with discharge port to pressure line and my best guess is a dump valve that opens on de-energization to release brakes.
Circuit board, looks a bit toasty in one corner.
Source of leak, undetermined.
The recall inspection procedure has been previously posted and it shows drilling a hole into the case from the BOTTOM. The recall inspection was done at selling dealer and re-installed, I chose not to trust old recalled unit and replaced, my call. When I removed it to install Carlisle, WOW, hole is thru the side of the case, not the bottom. The correct location would have drilled between components, not into one. Notice drilled hole is at the point where the recall instructions show as the drill to depth. Notice that the drill went thru one of the circuit board chips, still have chips of the chip and all of the plastic case to back up drilled in incorrect location claim.
I'm not drawing solid conclusions of how it worked, only observations about basic internal components of ActiBrake.
2005 Dodge Ram 2500 5.9L 6 Speed
16" Michelins, Hi Spec Wheels, Max Brake, Carslile Actuator, Equal-i-zer, Dill TPMS. Campfire cook.