I've looked thru brake plumbing threads but they haven't quenched my thirst. I am running Lincoln drum brakes all around on my roadster with 820-15 tires on back and 560-15 front . Should I run a proportioning valve or something to control brake bias between front and rear ? What are my options for running thru the frame fittings ? Remember, I am trying to resemble an early sixties build. I will appreciate your opinions. Thanks , Bill
With 4 wheel drums, no need for a proportioning valve. you will need 10 pound residual valves in the lines to the front and rear wheels, (assuming you have a dual master cylinder) To stick with a early 60's vibe, weld or bolt small brake hose tabs to the bottom or top of the frame and run your hard line to it. Thru the frame fittings is more of an 80's street rod thing. 39 or 40 ford front brake hose frame brackets work great and are not hard to find. pretty sure you can get them from Bob Drake.
With the same brakes, front and rear, but with dramatically different tires, you should install an adjustable proportioning valve. You do not want those big rear tires locking up early. The valve can be placed where it is not easily seen so that it does not distract from your early sixties build style.
I would run a proportioning valve just to have the ability to fine tune it. Residual pressure valves if teh brake master is below the level of the wheel cylinders. I used thru-frame fittings to run the front lines, but if that's too street-roddy for you, measure the max outside diameter (hex) of the inverted flair nuts you'll be using. Research grommets with a panel hole that OD (or the next available size) and an ID matching your brake line dia (3/16"?). Drill the rails that panel OD, split the grommet so you can get it around the line and in the rail hole. Provides a clean way of passing a brake line thru the frame rails without the "billet" look.
This may be a bit clearer. On the left, you can see where I ran the rear brake line (below) and fuel line (above) thru the center cross-member. Grommets are a must.
I would also install an adjustable proportioning valve. It's money and time well spent on a non-stock custom system to keep the rears from early lock up. Residuals were used and needed on all vintage drum brakes, regardless of master location, but will help minimize pedal travel even on later drums. If none are located internally in the master you use, install 10 # valves inline and close to the outlet ports.
I would use a prop valve for sure. I also like the look of through the frame fittings. Here's a roadster I am doing with the Lincoln brakes, and through the frame fittings I found. I use the Napa hoses because the ends are silver, part UP7600 on the front. I use hose UP4900 on the back with a standing bracket, let me know if you want a pic of how that looks.
Brake proportioning valves are vastly overrated IMO. Keep in mind that prior to '67 when dual brake circuits became required, you rarely if ever found them installed OEM. They gained in popularity after '67 when disc brakes showed up and the valves allowed the OEMs to limit their brake parts combinations and 'adjust' any mismatch away. Before '67, Detroit sold (and rodders modified) literally millions of cars without them with little or no ill effects.
Here's the pic of the rear hose I belive it was for a 1 ton 39 ford truck? It has 5/8" - 18 external threads on the end so it could easily be put through an unboxed frame rail, crossmember or flat bracket with a jamb nut on it. I just used some scrap pieces I found under the band saw and drilled and tapped them and screwed the hose end in. I'm trying to attach a sheet I made up of all the rubber hoses from Napa that work good with the early ford brakes, I have the lengths and fitting ends on it as well, but I don't post on here. Patrick
Thanks Patrick , That was to be my next question ( hose length ) ^^^^ Ditto ^^^^^ I saved your rear hose pic . I like it. We had our last cruise for the year tonight. A fella brought his 30 Model A coupe highboy that was built ( supposedly ) back in the sixties. It had a simple tab welded to the bottom of the frame for his brake hose. I'm giving this some thought. I appreciate all the input from you guys. Thanks , Bill
DOT brake performance requirements were minimal until the mid '60s, when proportioning became standard with front disc brakes because of the almost 2 to 1 pressure requirements of disc vs drum brakes. But proportioning could have been very beneficial with some earlier factory drum/drum systems, as many accidents caused by early rear slide may have been prevented, and is why, imo, an adjustable prop valve is good idea today with any custom non-stock brake system, including disc/drum, disc/disc and drum drum. Have to disagree with you Steve, but the problem is prop valves are not totally understood by many on the HAMB, along with some well known brake component suppliers. Residuals come in a close 2nd.
I'll agree with that statement.... I've installed three adjustable proportioning valves over the years on various modified cars (upon recommendation from 'experts'), and in two cases got the best braking results with the valves wide open; in other words, they weren't needed. The third one was installed on a very nose-heavy pickup, on that one the valve helped. To tell the truth, with the OPs big'n'little tire combo, I'd be more concerned with the front brakes locking before the rears, and a proportioning valve won't help with that. If you really want to CYA, decide where you would put the valve if needed and route/install a line coupler there. If you have rear lock-up braking issues, it will be a simple matter to install the valve in place of the coupler later.
An adjustable proportioning valve "wide open" simply means proportioning begins at a higher system pressure, usually around 1000-1200 psi. Normal braking may be fine without the valve, but panic stops, especially with power assist, would be in this higher pressure range. As to the last sentence, the front brakes should always lock before the rears, and is the whole purpose of the prop valve.
willyz guy , Patrick, I've been studying your rear brake hose pic and I'm curious about your lower shock mount. Got any pics? Thanks, Bill
Very very Nice. I shit canned those so-cal spring hangers because they would bend with spring loads. Check them before you put it on the road.
In regards to "thru frame" fittings I just copy what a stock 1940-1948 Ford car had. The specialty fittings make for a nice clean installation and all the parts are available at the restoration places. Sent from my iPhone using H.A.M.B.
Thanks 31 Vicky, I might gusset them just to be safe. I have used them on previous cars that have racked up miles on them with no issues that I know of. A few years back I got a set and one had a bad twist in one and I straighted it out and thought it didn't take as much effort to straighten it as it should have for a forged part. I used to make my own because I can't stand to use the flat steel ones.
Just for you and Not to hijack this thread. https://www.jalopyjournal.com/forum/threads/rant-save-your-money.863086/ It's closed but goes over the bending issue
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