Proportioning Valve Routing Plumbing Help

Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic

   The first photo is a combination valve (pressure differential switch and proportioning). The proportioning valve is under the nut on the right. Older drum brake cars didn't have that nut on the side. Some combination valves (mid 70s) also have a metering valve. Metering valve combos have both front brake lines on the valve instead of one in a T between the combo valve and master (usually the left front off the T). 

65-66 disc brake cars don't use a proportioning or combo valve, simple switch block like drum brake cars. They used non-servo rear brakes to reduce rear brake pressure/lock-up. 

67-70 disc brake cars used the same switch block as drum brakes with a proportioning valve in the rear brake line, bolted to the rear sill near where it kicks up over the rear axle. I could be off a year here, going by memory... might be 68-70, with 67 using non-servo like 65-66.

71+ cars used a combo valve. 71-74 or so used one with metering, later eliminated the metering valve. 

Author	Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic
farna Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19692	Post Options Post Reply Quote farna Report Post Thanks(0) Quote Reply Posted: Mar/16/2017 at 6:36am
	The first photo is a combination valve (pressure differential switch and proportioning). The proportioning valve is under the nut on the right. Older drum brake cars didn't have that nut on the side. Some combination valves (mid 70s) also have a metering valve. Metering valve combos have both front brake lines on the valve instead of one in a T between the combo valve and master (usually the left front off the T). 65-66 disc brake cars don't use a proportioning or combo valve, simple switch block like drum brake cars. They used non-servo rear brakes to reduce rear brake pressure/lock-up. 67-70 disc brake cars used the same switch block as drum brakes with a proportioning valve in the rear brake line, bolted to the rear sill near where it kicks up over the rear axle. I could be off a year here, going by memory... might be 68-70, with 67 using non-servo like 65-66. 71+ cars used a combo valve. 71-74 or so used one with metering, later eliminated the metering valve.
	Frank Swygert

rebel-misfit Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Jul/02/2014 Location: Central Florida Status: Offline Points: 96	Post Options Post Reply Quote rebel-misfit Report Post Thanks(0) Quote Reply Posted: Mar/16/2017 at 11:42am
	Cool. Okay, here's what I'm doing. I have a '75 Gremlin that I'm completely redoing the entire braking system. I purchased the car with no rear end, no brake lines. The braking system was completely gutted other than the front drums and master cylinder. I have a '77 AMX Hornet as a donor, so I took the rear end, combination valve and complete disc brake set up off and put it on the Gremlin. I bought new brake lines and am going to finish running them real soon. I will also be using the power boaster from the Hornet. So, in other words, it's all '77 AMX Hornet breaking/suspension on a '75 Gremlin. (Also, if curious, the Hornet was too far gone to save;)
	Three 1970 Javelins 1970 AMX 1970 Rebel 1975 Gremlin 1976 Gremlin 1972 Javelin 1974 Javelin 1977 AMX Hornet 1974 4 Door Matador

rebel-misfit Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Jul/02/2014 Location: Central Florida Status: Offline Points: 96	Post Options Post Reply Quote rebel-misfit Report Post Thanks(0) Quote Reply Posted: Mar/16/2017 at 11:46am
	The fist pic posted here is the one off my '77 AMX Hornet going on to my '75 Gremlin.
	Three 1970 Javelins 1970 AMX 1970 Rebel 1975 Gremlin 1976 Gremlin 1972 Javelin 1974 Javelin 1977 AMX Hornet 1974 4 Door Matador