The Rodding Roundtable
Motorhead Message Central => Rodder's Roundtable => Topic started by: 416Ford on August 14, 2023, 08:07:48 AM
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.
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
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.
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.
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.
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.
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?
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.
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
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? ;D
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?