Brakes

[416Ford]

So we had the wheel bearing issue and it tore front caliper off the car when it came apart. My question is how do I get a proportioning valve with no residuals in it? In a newer car the proportioning valve would have close off the front brakes and I would have had rear brakes still. In this case, I have a dual master and I had no rear brakes. Photo attached is the setup I have currently.

[WZ JUNK]

Something like this.   https://www.speedwaymotors.com/GM-Disc-Drum-Proportioning-Valve-for-1-2-20-9-16-18-Outlets,9878.html?utm_medium=CSEGoogle&utm_source=CSE&utm_campaign=CSEGOOGLE&gclid=Cj0KCQjwoeemBhCfARIsADR2QCt4I4y7cIM55houVIBn0DSqrdk81cujr-1eeHa6psOxx3uZ4vudPmUaAuhrEALw_wcB

[lofat46]

I have a firewall mounted master on my '48 Ford and had the same on my old '46 Chevy and only had the proportioning valve pictured. Never needed a check valve or separated proportioning valve.

[416Ford]

Under the floor mounting must have check valves to prevent feed back.
John, can the one you show be used with the valves in the system?
I see it says two front lines, I would need One front line and one back line.

[WZ JUNK]

I recently replaced the one on my old truck.  I used the residual valves with one of the factory style proportioning valves like the one in the link.  My master cylinder is under the floor.  I plumbed it so that I used two lines for the front because I already had that from the old system.  That is the way the factory setup was.  I do not know if you could plug one of the ports and just use one to supply the front brakes.

[416Ford]

Looked at the Q and A on Speedway site and this is what I need. I can run this with under floor setup and I can plug off one of the lines for my setup. Thanks John.

[Bruce Dorsi]

If the set-up is the same as 416's pic, doesn't a dual master cylinder prevent complete failure of a brake system if either the front or rear circuit is compromised?

[WZ JUNK]

The way I understand the system uses the proportioning valve to divert the fluid in a situation when the front or rear brake system fails.  The shuttle in the proportioning valve closes off the failed part and diverts fluid to the other part.  So it is a combination proportion valve and a safety mechanism that enables you to have some brakes if part of the braking system partially fails.

[enjenjo]

GM calls it a Combination valve. You can find them cheaper on Amazon. You should also get the tool that holds the shuttle valve in place for bleeding the brakes.

https://www.amazon.com/s?k=s10+brake+combination+valve&crid=2RBMBG0LJFYDY&sprefix=s10+brake+combination+valve%2Caps%2C126&ref=nb_sb_noss

[416Ford]

Bruce, I thought the same thing. The proportioning valve is a good winter project for anyone who doesn't have one.

Thanks for the heads up Frank, where were you yesterday before I ordered the other one? 

[kb426]

I needed some time to think about this. (thinking is a problem) I have done a similar setup on the last 2 builds. It seems to me that the problem is presented by the adjustable proportioning valve. It takes pressure to make it through the valve. Depending on the style of a double master cylinder, it is possible for all of the fluid to drain out and not have any brakes. The newer stuff that I'm using has a very small division in the reservoir. I wonder if the proportioning valve will retain enough fluid to make the rear brakes work against the adjustable valve. Am I missing something here?