Brake Residual Valve Location Help
 

I think I got a little to excited that I was finally starting to get my brake lines run. I've run into a little problem with plumbing my front brakes.

I did the rear correctly as in the first mbmbrakes picture with a single line run to the back with one 2lb residual valve.

Then I got a little to excited and ran one line to each front wheel to the wilwood combination valve. It's a little more brake line but I figured I would use the two "front out" ports on the wilwood because I didnt have a plug. The origional plan was only to run one line to the front then "tee" off for the passenger side.

I havent plumbed the master cylinder yet to the wilwood so I'm ok there.

Now the question is.....Can I plumb in the 2lb residual valve just off the master cylinder before the wilwood? or does it have to be after as shown in the second mbmbrake image i modified? if so then I will need to go buy another valve and re-cut/flare them in somewhere.

Any help would be appriciated. Pictures are attached.

Re: Brake Residual Valve Location Help
 

I'll install the rear 2lb residual valve next to the 't' fitting just above the rear diff on drivers side. Then run the rest of the rear brake line up the frame to the wilwood bottom remaining 'RO' port. Then I'll just to run my two lines from the MC to the wilwood top 'RI" and 'FI' ports.

Any response to post 1 would be great. Thank you.

Re: Brake Residual Valve Location Help
 

I mounted mine right off of the master cylinder, before the "tee" for the front brakes.
https://scontent-ort2-1.xx.fbcdn.net...3f&oe=59FAD341

Re: Brake Residual Valve Location Help
 

Thanks Black_Sheep. After doing a little more thinking about it I guess I answered my own question where to put the front residual valve. I'll install it just off the master cylinder then run line to the wilwood 'FI" proportioning valve port because reading the wilwood manual says.

"Wilwood’s new Combination Proportioning Valve substantially simplifies mounting, plumbing, wiring and brake proportioning adjustments on vehicles with custom brake systems. The combination block maintains full isolation between front and rear fluid circuits and can be used in conjunction with any tandem outlet or dual mount master cylinder assemblies. The rear circuit has a single inlet and single outlet with the adjustable proportioning valve. The front circuit has a single inlet with two outlets. It can be run as a single outlet with one outlet plugged, or used to split the plumbing on its way to the front calipers."

The adjustable valve is only for the rear which I plumbed correctly with the residual valve near the rear brakes. I guess I should have thought this through before starting to freak out LOL.

Re: Brake Residual Valve Location Help
 

I would say the residual valve could be mounted in either position depending on ease of mounting but, if it were me, I would mount a single res valve next to the master cyl.
the other issue you may encounter is the system being a bit difficult to bleed due to the "P" trap that is in the lines near the firewall mounted valve. there is a low spot there that could result in air being trapped. it may be better to run a small spiral of line below the valve which doesn't allow any line to go up-down-then back up. there are also stainless flex lines available that work well in this scenario because they allow some flex due to cab/line movement etc. you could attach/clamp the lines at the frame then run flex hose up to the valve and back.
running dual lines to each front brake is great but really, for the amount of fluid the calipers require, a single line run from the master that is run up to a "T" that goes to each wheel would also work.

Re: Brake Residual Valve Location Help
 

Outside of ease of access I'm just wondering why one would mount the adjustable proportioning valve up that high on the firewall and run that much extra line for the rear brakes. I've got one for mine but plan to mount it inline behind the master cylinder.
I'm with Dsraven in that that setup looks like a built in brake bleeding issue.

I've fought the Ford brake switch on mine for years replacing it about once a year and am going back to the stock switch under the pedal this go around. Maybe because mine was under the truck or what not but it failed about once a year or every other year.

Re: Brake Residual Valve Location Help
 

I agree, I had to re-plumb my lines from the MC to proportioning valve because I turned the loops vertical instead or horizontal. I tried for two weekends to get the things bleed before I realized I could not get the air pockets out of the upper part of the loop. Turned them 90 degrees and was done in half an hour. Under floor is fine, basically you fiddle with at first to get things right then forget about it.

Re: Brake Residual Valve Location Help
 

I finished plumbing the brakes this weekend, the MC is bench bled and installed. Just have to bleed the brakes now. Here are some updated pictures.

The two top ports are the 'FI' and 'RI' ports from the Master Cylinder. I hope there is not to much of a curve in those to? I was talking with a friend and he said the two bottom lines for 'FO' might be ok because of the front residual valve. I guess the only thing I can do is try and bleed the lines and see how they feel. If not I'll have to slice the lines over and re-flare them or get some flex lines like dsraven said, or should I just do that anyway for the bottom 'FO' ports and save myself some in-needed hassle?

Re: Brake Residual Valve Location Help
 

few more

Re: Brake Residual Valve Location Help
 

Is your master cylinder actually below the level of the wheel calipers? If not you dont need residual valves.

Re: Brake Residual Valve Location Help
 

Yes.

Re: Brake Residual Valve Location Help
 

Some good info on all the parts you are playing around with ....

Here's an excerpt from an article by Dean Oshiro at Hot Rods USA:

Residual valves are pressure valves used to retain pressure in the lines. The most common use is on a hot rod when there is a floor mounted brake pedal and master cylinder. Mounting the master cylinder (M/C) below the floor positions it below the calipers. Gravity will cause the fluid to flow away from the calipers. The residual valve will retain pressure within the lines. (i.e. 2 pounds residual valve will retain 2 pounds of pressure, 10 pound will retain 10 pounds.) Drum brake master cylinders have residual valve(s) built into the master cylinder. This is needed to maintain pressure against the cup seals in the wheel cylinders. If you are using a disc brake master cylinder or after market you will need to install a 10 pound residual valve for the drum brakes. Do not install a residual valve if your master cylinder already has one in it. This will cause the brakes to lock up after the second application to the brake pedal.

Distribution Blocks or Combination Valves: One of the biggest misconceptions is the distribution block or combination valve. Almost every factory car has one. This usually serves as a metering block to adjust the proportioning to the rear brakes, as a "T" fitting for your front left and right front brake lines and brake light warning switch. What people fail to understand is that each car is "engineered" for a specific distribution block based on weight, braking characteristics and tires. So generally most factory cars have different blocks.

Ask yourself this. How can one distribution block be engineered for all applications? So, we have this 23T with tiny tires in front and big tires in the back, we have a 57 Caddy and a 57 Chevy pick up. Do you really think the braking is the same for all three vehicles?

Save yourself some headaches install a adjustable proportional valve in the rear brake lines.

Copyright reserved by Dean Oshiro.

Re: Brake Residual Valve Location Help
 

That's what the wilwood has. Built in rear adjustable proportional valve.

Anyone have any thoughts on the two upper lines going into the wilwood? Those are from the MC for front/rear. Or is the routing only a problem on the two front lines coming out of the bottom?

Re: Brake Residual Valve Location Help
 

if it were me I would rework the upper lines (I assume the outlets) so they come upwards in a coil, like you wrapped them around a can of soup. you will still have some extra line for repairs etc but they would not be looped up higher than the res valve. then purchase a couple of "brake bleeder repair" fittings, available at napa ( UP BF117, they are pipe thread fittings with a bleeder screw in them) and install them in T fittings at the outlets of the block which should be the highest part of the system. 3/16-inch tubing is one of the most common sizes used in brake systems, which makes use of a 3/8-24 inverted flare nut. you would need a T fitting with the proper threaded ports. install the T's so the brake lines will come out the sides of the T and the bleeders will be across from them on the other leg of the T. the base of the T would go into the valve. that will allow you to bleed the air from the system at the high point because the block will be the highest part of the brake line system. it is probably going to be hard to get the air out of that area unless you have some bleeders there. once bled at the valve then bleed at the calipers. the other option is to manually bleed the system at the outlet fittings of the block by cracking the lines while a buddy steps on the brakes. just make sure the buddy doesn't let the pedal go until the lines are tight again. same theory as manual bleeding at the bleeder screws. this is definitely going to be messy and remember brake fluid usually softens or removes paint.

OR,

install the valve down low, like near the master cyl as shown in the illustration. that way you may not have the bleeding issue. once the valve is adjusted you will probably not be playing with it anyway. a few slides under the truck until you get it adjusted may be worth it. you could also cut an access hole in the floor of the cab for access if you think you need to be able to get at the valve often enough.

Re: Brake Residual Valve Location Help
 

Thanks for the great information dsraven. As I've said before you are a great wealth of knowledge.

What I might do instead is to get some 'L' 3/8-24 fittings and install them in the wildwood block. Then route the lines at a 90 degree angle into the block illuminating the loops. That should resolve the issue I would think and an easy fix. thoughts?

Re: Brake Residual Valve Location Help
 

that should work with a little extra stuff to tidy up as well. I would do the soup can spiral on the tubing attached to the bottom of the valve. just so the tubing is all lower than the valve is instead of going up past and then coming down into the valve which creats a high spot in the tubing before the valve. then do the 90 deg fitting and another soup can spiral on the lines attached to the top of the valve. the spirals give some extra tubing for repairs if needed as well as some room for body flex etc.
when you bleed the brakes start with a bench bleed of the master cyl, then go to the prop valve and loosen the tubing in the upper fittings like you would if it was a bleeder screw. that should help get the air out up to that point. when all good then do the furthest away wheel and then the second furthest away wheel and so forth till you have clean, fresh fluid at each bleeder and no air bubbles. remember to keep the master full so you don't suck in any air bubbles and have to start all over again. the pedal should be hard when done, no spongy feeling.

Re: Brake Residual Valve Location Help
 

Exactly, set it and forget it. Unless you make a drastic change in tire size or alter the brake system in some way, no further adjustment will be necessary

Re: Brake Residual Valve Location Help
 

Had a little time to work on the truck over the weekend. From the recommendation of DsRaven I made some changes to the residual valve and brake line routing. Hopefully this new setup will work better. Let me know what you think.

Re: Brake Residual Valve Location Help
 

i don't mean to hurt your feelings, but...
not sure why you'd go thru all the trouble to install the mc under floor and then plumb that mess on the firewall
an adjustable proportioning valve will be a one time adjustment, it's not something you need to tweak weekly
i'd change it as you have it drawn behind the mc

Re: Brake Residual Valve Location Help
 

I have a question, are you using copper line for your brake lines, or is that just the light or photograph making the lines look like they are copper?

Re: Brake Residual Valve Location Help
 

Copper Nickle easy bend lines.