I was never happy with the design of the parking brake vancle fron Matco. The mounting bolt clamps down on the valve body and cannot be torqued without locking up the valve. Also, the two-pice design does not provide a close tolerance to the bolt, so the valve can move around quite a bit when mounted.
I decided to rework the mounting method to suit my needs. After taking some measurements I determined that the mounting holes could be enlarged to 1/4" without comprimising the valve. In my drill press I reamed the holes to 1/4" I then took some 1/4"OD stainless tube and reamed the ID to 3/16". I made the stainless just a hair longer than the thickness of the valve body. Now the mounting bolts can be torqued to spec and a thin rubber washer applies the right ammount of pressure to the valve body while the bolts bottom on the tube.
While I was at it, I added a microswitch to the lever arm stop plate so that a light on the panel will illuminate if the parking brake is on. I still need to pick up some 4-40 locking nuts for the switch.
