I am in the middle of fixing up my 78 F150 and am getting to the brakes. They were always terrible since I bought it and the Brake light remained on. I noticed this weekend that the PO had plugged one end of the combination valve going to the front and ran a short line to a brake hose with two outlets from the other end going to the front. This fed both calipers. The rear was plumbed normal. My question is: did the guy put on the wrong combo valve or the wrong brake hose? I assume there should not simply be a port that is plugged. I have seen diagrams that suggest a center brake hose for my truck and some do not. Thanks for the help. And I wish you could see the amount of silicon this dude used on the motor I pulled.

 

You should only have one center hose, and that will feed the rear drums. There should be one port on the proportioning valve that feeds the single brake line to the rear, which then connects to the center rear hose that tees off for both rear wheels.

Each front caliper should have its own hose and line, which go to separate ports on the front of the proportioning valve. Nothing the previous owner did is correct. Either he installed the wrong proportioning valve, or something happened with the old setup and this was his "ghetto-rigged" solution.

 

YOW.

Your proportioning valve thinks that one outlet is plugged. Hence, the brake warning light is engaged. It works but not optimally and there is a reason there are two outlet ports on the combo valve... it was designed and engineered that way. That shadetree fix is, well, just plain wrong....

Danger Will Robinson! Danger! (Yikes!, am I dating myself?)



I just pirated the front brakes & suspension from a 78 for my 70 and yeah, there are supposed to be two hard brake lines to the front.

 

proportioning valves are hard to find, most parts stores dont carry them, which is strange because they are wearable parts...but there are a few companies online that started cutting their own out of brass blocks...i installed several on older cars recently with great results....sorry i dont know the companies name, but i found it on google fairly easily...

 

Master Power Brakes, Stainless Steel Brakes Corporation, Wilwood, Speedway Motors... NPD carries 'em too..

 

thats who i used, was only a day late of the estimated delivery and they bolted right up...cost about $80...

 

Thanks for confrming my thought. It is plumbed wrong from the valve to the front. Everything else appears stock. Luckily I didn't drive it much and the valve is correct.