Brake proportioning valve

[AydinZ71]

Hi folks! 
 

The race car came with this guy in the cabin. It was crudely installed, so I just fabricated a mount so the brake lines can persist in the tunnel and not run into the cab like they are now. Is anyone familiar with this valve, and is it any good? It looks like what MSA sold years ago. 
 

im also confused how this works with the OEM brake balance/manifold in the engine bay. I took the valve apart, and it looks to be a simple spring loaded globe valve with an an adjustment knob. Not too dissimilar to an adjustable fuel pressure regulator.

 

Just want to make sure it’s not junk since I’m going through the effort. Thank you all in advance!

 

-Aydin 

[jhm]

I'm not familiar with that particular prop valve, Aydin; but new ones can be had very readily and cheaply (30 or 40 bucks for a Wilwood).  There are a few choices you'll want to decide early on:  do you want to install it in the engine bay (for simplicity) or in the cabin, to give you the ability to adjust whilst driving?  And if the latter, do you want adjustment with knob-style or lever-style?  I think most folks opt for lever style, as it's easier to use when your concentration is focused elsewhere (like the 95 mph esses you're approaching!)

 

If you are incorporating an aftermarket valve in your system, I'd recommend deleting the OEM prop valve/distribution block....no need for two separate prop valves in your brake system.  A lot of people (myself included) also remove the OEM brake system failure warning switch when running new brake lines, and/or building a car for race applications.

[AydinZ71]

2 hours ago, jhm said:

I'm not familiar with that particular prop valve, Aydin; but new ones can be had very readily and cheaply (30 or 40 bucks for a Wilwood).  There are a few choices you'll want to decide early on:  do you want to install it in the engine bay (for simplicity) or in the cabin, to give you the ability to adjust whilst driving?  And if the latter, do you want adjustment with knob-style or lever-style?  I think most folks opt for lever style, as it's easier to use when your concentration is focused elsewhere (like the 95 mph esses you're approaching!)

 

If you are incorporating an aftermarket valve in your system, I'd recommend deleting the OEM prop valve/distribution block....no need for two separate prop valves in your brake system.  A lot of people (myself included) also remove the OEM brake system failure warning switch when running new brake lines, and/or building a car for race applications.

Thanks John!

 

I'm going to stick with this valve for now (unless someone else has negative feedback) since I can easily change it out later. I also already made the mount for it to be accessible through the center console (see pic). 
 

if I understood you correctly, I can run brake lines directly from the master cylinder to tees leading to each wheel? If so, I just need to keep track of which reservoirs feeds the front vs. rear brakes? The proportioning valve looks like it just restricts pressure to the rear wheels, unless the previous owner installed it incorrectly. 

[grannyknot]

 

2 hours ago, AydinZ71 said:

The proportioning valve looks like it just restricts pressure to the rear wheels, unless the previous owner installed it incorrectly. 

The rear brakes are the only ones you want a prop. valve going to.  I like the knob coming up through the console.

[jhm]

@grannyknot is correct....you only want the prop valve affecting the hydraulic pressure to the rear brakes.  I can't think of any situation where you would want a prop valve on the front brakes, and it's highly discouraged to do so.

 

Your MC should have a big "F" and a big "R" on each reservoir to indicate which is which.  An unless you have an early Series 1, all MCs should feed the front brakes from the rear reservoir (on OEM, it's bigger to feed the disc calipers; vs the smaller reservoir needed for the rear drum cylinders.)

 

Yes, you can run the line from the "F" outlet on your MC to a simple tee connection, and then run lines to each front corner from the tee.  Believe or not, I had a heck of a time finding a good solid tee connector with nice deep connection ports (to allow plenty of line connector penetration into the threads.  I ended up finding one in Latvia on eBay!!  😄

 

I'd put stickers with big directional arrows on that knob so that you don't forget which direction does what to the brakes (it happens...believe me!)

 

Finally, I know I've mentioned this to you before; but for the benefit of other folks on here, I absolutely love FedHillUSA for brake and fuel line supplies and components.  They also have a bunch of good tech articles on their website:  http://www.fedhillusa.com/

[JMortensen]

I had that prop valve on my Miata. Worked fine.

[AydinZ71]

Many thanks John! @jhm

I will take this feedback and run with it! I found 3/16” inverted flare lines with 10mm metric threads at O’reily’s, so I should be good on the lines. I plan to get the tees and any misc. fittings from McMaster Carr or Fedhill like you mentioned. 

 

as always, it’s the little things right? Still waiting on my 3/16” “rubber” lined tube clamps to come in from amazon. I need to weld-in some #10 nuts in the tunnel and underbody to mount the lines. Most of the existing mount points were either cut by my predecessor, or by me so I could eliminate rust. I’m going to share a single mount point for the brake and 3/8” fuel line for simplicity. 
 

thanks again for it all your help guys! 

[grannyknot]

@jhm,I too love Fedhill but a friend turned me on to these guys, https://www.thestopshop.com/collections/copper-nickel-cupronickel-tubing-kits

The wall thickness is the same a Fedhill but the price difference is substantial, I like their armor  as well, also not expensive.  I haven't purchased anything from them yet but my friend has and is very pleased with the products he has received.