AS BEST I CANT TELL based on my 73 wagon is the following:


1. Feeds to the rear brakes.
2. Comes from the front of the master cylinder (presumed for the rear brakes)
3. Comes from the rear of the master cylinder (presumed for the front brakes)
4. Feeds to the passenger side front caliper.
5. Feeds to the driver side front caliper.
6. This is an electrical switch. AS BEST I UNDERSTAND if one half of the hydraulic circuit fails a rod like piston slides to block the failed section. This helps to maintain pressure in the unfailed section. It also activates the switch that lights the "Brake" light on the dashboard. I'm not sure any of the part is proportioning, but possibly only a distribution block, but I don't know for sure. IF the piston has slid into a blocking position it might stay and need to be repositioned. I've never had one apart before so I'm just surmising based on logic. I'd think access would be through unthreading the switching. Take note that there MIGHT be springs and check balls inside. Also, the mount position is vertical with the switch towards the front f the car.

In the picture 1 and 2 are for the rear brakes. 3, 4, 5 are for the front brakes. 6 which is the fault switch is between the two. 1 and 2 probably "pass thru" to each other. Likewise 3, 4 and "pass thru" to each other. Spraying brake cleaner inside would likely clean any debris out. The problem that COULD arise is if the plunger in 6 (the switch) was moved by a pressure imbalance and and is hung up. Then half the circuit (front or rear) would not receive pressure. Hopefully that is not the case but something to be aware of.