Newbie here and pretty sure this has been answered before. My searches haven’t help.
I’m helping my son install power and front disc brakes. We’re working on a 1969 F100, donor was 1979 model.
after installing the proportioning valve, do you eliminate the balancing valve or somehow connect it to proportioning valve?

 

You can leave it inline. So Master has front and back. Proportioning valve has front and back inputs. Use just the two outputs from the front and back (cap the other front). Run those down to the frame rail valve/distribution.

Few things to consider before you start.

• Do you have the brake line mounts for the frame rail? You will need these or have to fab/modify the originals.
• Order the longer brake lines for the 75+
• Consider an aluminum master, the cast iron ones rust instantly.
• New master cylinders may not have the residual pressure for the rear drums...so you may need to add that inline as well.
• Check the king pins before you start, easier to do them on a bench than under the truck.

 

Get rid of the stock valve and all the old lines.. Get a new block with a proportioning valve and Nickel/Copper brake lines from Napa and replumb the entire system. Should take about 3-4hrs that's how easy it is. Yes you will need the frame brackets for the front lines. Don't paint the Master, Marvel Mystery oil it and it won't rust.

 

Correct me if I’m wrong.
connect the two output lines from master cylinder to the two input locations on proportioning valve
block off one of the front outputs on proportioning valve.
connect the front output and rear output from proportioning valve to the two input locations on the balancing valve.

 

Yes. This will work fine. Be sure to bench bleed the master, and proportioning valve before install.

 

??????? Why would you want both valves??????? One or the other.

 

I thought the balancing valve was required if using OEM proportioning valve and that proportioning valve/balancing valve combo were only available as a aftermarket product.

 

Yeah, I think terminology gets people in trouble here.
If you have Disc and Drum brakes on the same truck. You need/should have, Metering Valve, Proportioning Valve, Residual Valve, and the Pressure Differential Switch.
If you have a combo valve specific to disc/drum, then it should have the metering valve with the pressure diff switch and the proportioning valve for the rears. Still need to add the 10lb Residual valve for the rears...

Valve in the frame is just a Pressure Diff Switch. So if you just add a proportioning valve, it is suggested to leave the Pressure Diff Switch in the truck, run inline.

These are BRAKES, so please be careful...obviously. The goal is that when you hammer the brakes because of some idiot in front you, the Metering valve holds off the front discs a little so that you don't dive the truck and loose control. This gives the rear drums time to catch up and 4 wheel decelerate. The Residual valve leaves 10lbs of line pressure so that the rear drum cylinders are ready to go. Then the proportioning valve helps to avoid the rear lock up by limiting the max pressure the drums can receive (the brake cylinders can only do so much). Finally, in case of failure of the front or rear, the Pressure Diff Switch will save the working brakes allowing you to stop on just the front/rears by blocking off the other ports.

Hope that helps...

 

I did read what you typed, but I don't see why OP needs any valve other than the proportioning valve. Ford didn't have two from the factory. What OP is doing is upgrading his Bumpside brakes to factory stock 75/ Dentside brakes. I would plumb it just as the brakes were on the 1979.

 

I agree with the idea that 1975 Brakes are just fine, hence the reason we love these trucks. However, some things changed around us (texting drivers, 90mph is the new 55, idiots cutting people off etc...) and then some aftermarket parts also got cheaper. So a few items, the 1979+ valve is a combo of sorts, new/rebuilt/OE spec master cylinders no longer have residual pressure valves in them (however my racing Wilwood master for disc/disc on a different car DID have one that I had to remove....weird), and giving people proper advice to the parts and purposes means no harm to those that can do without.

I built my 71' with my 16yr old son, so I went the extra mile to make sure it is safe as can be for his first vehicle. Some friendly folks at the Semi-Truck brake service down the street were nice enough to explain all of this to him. They even hooked up a pressure gauge to show him the differences between newer and older masters, etc... with cut-aways for the drum cylinders and all. So it was a good learning experience all around. In the end, it's just my .02 and nothing more. Here is a video explaining the whole thing in case you think I am not credible.

Again, I agree with you and Christmas... Old trucks are old and trucks...but hey...nothing wrong with info.

 

"Truer words were never spoken", or in this case, written... Another great saying is "A picture is worth a thousand words"...

As I am also attempting disk brakes on my '68 F100, and I'm at the point of new lines and what to do with the old "distribution block" (not a term I've seen here), it would help me greatly if someone could provide a picture (drawing, photo, schematic) of the various options.

Thanks,

 

I just watched the video provided (probably should have done that first), very informative. I'm still a little unclear exactly what I need, but that's more a result of not knowing exactly what I have. I'm dealing with an after-market kit that was installed by someone who neither used the instructions during install, nor kept them so I can refer to them now... Nothing new, I'm working through the same problem he created with the American Autowire harness...

 

The kit you have is for 4 wheel disk brakes, disk brakes take more pressure than drum brakes, you should have a booster, the residual pressure valves are a must for a frame mounted system, they are not part of the proportioning valve.

You need 10 PSI residual pressure valve for drum brakes and 2PSI for disk.

I have 2 trucks with frame mount dual master cylinder and I really like the setup, I like the look of the old school through the floor pedals and they work great. I do plan on putting a remote reservoir on one of the trucks that is to low to crawl under.