I just lack finishing up on a disc brake conversion. I got the master cylinder and proportioning valve from a junk yard. The instructons for this converison state that the front brakes go the front of the the porportionig valve and the rear to the rear. My question is: On the master cylinder is the front small chamber or the rear large chamber for the front brakes? In other words to the feed lines to the porportionag valve cross or go straight down.

 

I feel your confusion....went through the same thing just one week ago, the larger back bowl goes to the front inlet on the schematic, the smaller front bowl goes to the back inlet....the idea behind the schematic is that "front inlet" means inlet that supplys front brakes...which is always the larger bowl.
If you plumb it backwards (like I did at first) you will have next to no brakes on the front and you will lock up the rears...which means you will have a hard time stopping....

Someone should really clarify that schematic...

 

 

The larger master cylinder chamber is for the front brakes. Does not matter if the larger bowl on the master cylinder is in the front or the rear of the cylinder. Many times you must cross the lines from the master cylinder to properly connect to the proportioning valve.