modern dual circuit air over hydraulic brakes

[fleetmech]

I decided to start a new thread instead of adding more to the enormous dual circuit threads already in existence. Also, these ideas are not new. I came up with them, then did some research and realized they've already been done, even at the OEM level, just apparently not for deuces.

Please note, the idea of this build would not be for stock looks, but ultimate safety and modern part availability.

Essentially the idea is this: instead of adding the cost and complexity of hydroboost/ hydramax, why not use air to operate a dual circuit MC? After all, the stock deuce airpack is essentially a fluid controlled air piston that pushes on a second master, and the m105 brakes are 100% an air chamber pushing on a master.

We could utilize the reasonable cost MCs available and activate them using an air brake chamber off a big rig controlled by a big rig air treadle. Stepping on the brake would send proportional air from the trucks already existant air tank(s) to activate the air chamber which would push on the master. This would eliminate hard to find airpacks, hydraulic systems, pumps, backup pumps, wiring, pedal/ lever ratios, mounting obstructions and probably be cheaper. It could also be built out of good DOT approved parts common at local truck stores and would then be easy to service.

This system could be mounted just about anywhere convenient on the truck in any form you desire and require only the standard brake connections, flexible DOT air lines, a treadle, and maybe a check and quick release valve or two. it would take some fabrication, but nothing outlandish. A piece of extra heavy wall box tube and some gussets may be all thats required.

In its most basic form this would give split hydraulic circuits, and a single air circuit. This may be enough for some, as air systems are quite robust and can often function even with some loss through a damaged line. If you would like the system to be super redundant, there are several options. Firstly, you could use a spring brake chamber for your actuator and plumb in a standard truck parking brake valve. In the event of air loss, the brakes would come on (probably quite hard), but it would get you stopped as a complete fail-safe and could serve as a temporary all wheel park brake if needed. It would probably be wise to cage the spring when the truck is left for long periods...

The second option would be to use two single masters (deuce oem ones?) like the airforce trucks did, but use twin modern air chambers to actuate them. This would give two complete air and fluid systems and if combined with two spring chambers, you would have a whole lot of redundancy at your command.

Since the air treadle would be controlling the air, you could retain or modernize your air lines to the rear for trailer towing.

A quick google of "air operated master cylinder" will show you exactly what Im talking about.

What do you guys think?

 

[Mullaney]

I decided to start a new thread instead of adding more to the enormous dual circuit threads already in existence. Also, these ideas are not new. I came up with them, then did some research and realized they've already been done, even at the OEM level, just apparently not for deuces.

Please note, the idea of this build would not be for stock looks, but ultimate safety and modern part availability.

Essentially the idea is this: instead of adding the cost and complexity of hydroboost/ hydramax, why not use air to operate a dual circuit MC? After all, the stock deuce airpack is essentially a fluid controlled air piston that pushes on a second master, and the m105 brakes are 100% an air chamber pushing on a master.

We could utilize the reasonable cost MCs available and activate them using an air brake chamber off a big rig controlled by a big rig air treadle. Stepping on the brake would send proportional air from the trucks already existant air tank(s) to activate the air chamber which would push on the master. This would eliminate hard to find airpacks, hydraulic systems, pumps, backup pumps, wiring, pedal/ lever ratios, mounting obstructions and probably be cheaper. It could also be built out of good DOT approved parts common at local truck stores and would then be easy to service.

This system could be mounted just about anywhere convenient on the truck in any form you desire and require only the standard brake connections, flexible DOT air lines, a treadle, and maybe a check and quick release valve or two. it would take some fabrication, but nothing outlandish. A piece of extra heavy wall box tube and some gussets may be all thats required.

In its most basic form this would give split hydraulic circuits, and a single air circuit. This may be enough for some, as air systems are quite robust and can often function even with some loss through a damaged line. If you would like the system to be super redundant, there are several options. Firstly, you could use a spring brake chamber for your actuator and plumb in a standard truck parking brake valve. In the event of air loss, the brakes would come on (probably quite hard), but it would get you stopped as a complete fail-safe and could serve as a temporary all wheel park brake if needed. It would probably be wise to cage the spring when the truck is left for long periods...

The second option would be to use two single masters (deuce oem ones?) like the airforce trucks did, but use twin modern air chambers to actuate them. This would give two complete air and fluid systems and if combined with two spring chambers, you would have a whole lot of redundancy at your command.

Since the air treadle would be controlling the air, you could retain or modernize your air lines to the rear for trailer towing.

A quick google of "air operated master cylinder" will show you exactly what Im talking about.

What do you guys think?

.
My opinion - for what that is worth - is that your idea is pretty sound.

The lawyer dogs will be all over you if anything ever goes wrong though. They will be asking questions about your personal pedigree and where your engineering sheep skin is. Even if your idea is better by thirty years, it would be a hard sell in court...

 

[fleetmech]

I suppose I should have clarified that I was looking more for thoughts on the mechanical rather than the legal, but its not invalid as we're never far from the law these days.

Hot rodders have been swapping and modding brake and steering systems since about 6 months after cars were invented. There's liability in it, as there is in just about everything these days from using a public bathroom, to hydromax swapping, to driving a historic vehicle in general. One might even consider that any system that makes drama statistically less likely, is something to be considered. I hate to put this bluntly but I would surmise that many 'bobbers' didnt have their chassis alterations designed by an automotive engineering firm or spring mounts welded by a certified welder and then x-rayed.

I dont remember the forum rules about posting non vendor site links, but the exact system I described is (or at least was recently) available for purchase as a kit. That would certainly put some else's name to any issues that might be of concern.

 

[Mullaney]

I suppose I should have clarified that I was looking more for thoughts on the mechanical rather than the legal, but its not invalid as we're never far from the law these days.

Hot rodders have been swapping and modding brake and steering systems since about 6 months after cars were invented. There's liability in it, as there is in just about everything these days from using a public bathroom, to hydromax swapping, to driving a historic vehicle in general. One might even consider that any system that makes drama statistically less likely, is something to be considered. I hate to put this bluntly but I would surmise that many 'bobbers' didnt have their chassis alterations designed by an automotive engineering firm or spring mounts welded by a certified welder and then x-rayed.

I dont remember the forum rules about posting non vendor site links, but the exact system I described is (or at least was recently) available for purchase as a kit. That would certainly put some else's name to any issues that might be of concern.

.
Absolutely! And bolting on parts that have "a pedigree" of sorts is definitely designing from scratch. And, like you said too - engineering done by somebody else helps with the drama.

I think you could easily post "screen grabs" to show the design elements without any complaints from the Mods. One of the main complaints is disappearing links - and pictures posted will solve that problem in the future.

 

[fleetmech]

Air-Hydraulic Brake System with 1-3/4 to 2 inch Master Cylinder for Medium Trucks

Our Air-Hydraulic brake system uses an air-valve/pedal assembly to apply a remotely mounted air brake booster. It uses air pressure from a belt driven or 12 volt onboard air system to control the air-hydraulic booster, just like the brake system on super sized big rigs and buses, but it pushes a...

www.powerbrakeservice.net

I understand the misery of disappearing links, But most of the pictures I can find might be copyrighted, and I'd rather deal with our mods, so here is a link to a setup that looks like it would work in our rigs.

 

[banditt1979]

Air-Hydraulic Brake System with 1-3/4 to 2 inch Master Cylinder for Medium Trucks

Our Air-Hydraulic brake system uses an air-valve/pedal assembly to apply a remotely mounted air brake booster. It uses air pressure from a belt driven or 12 volt onboard air system to control the air-hydraulic booster, just like the brake system on super sized big rigs and buses, but it pushes a...

www.powerbrakeservice.net

I understand the misery of disappearing links, But most of the pictures I can find might be copyrighted, and I'd rather deal with our mods, so here is a link to a setup that looks like it would work in our rigs.

I like the idea. You would spend a lot more than that for 2 air packs and a dual master. I found a dual master that almost bolts up where the single goes but couldnt determine all the specs as the dorman guy could not provide.

 

[DaneGer21]

I like the idea. You would spend a lot more than that for 2 air packs and a dual master. I found a dual master that almost bolts up where the single goes but couldnt determine all the specs as the dorman guy could not provide.

I still think something like this would be ideal, with the addition of another air pack. If the specs would work of course. The 2nd pic would include a clutch setup if needed.

 

[sue]

I still think something like this would be ideal, with the addition of another air pack. If the specs would work of course. The 2nd pic would include a clutch setup if needed.

The problem is that your probably a billionaire or at least a hundred millionaire right? That’s why melvin belli will take you to court for years if you modify your beat up old army truck and improve the brakes.
And then have an accident. Be very careful because there is a .0000000000000001% chance of that happening. You’ve been warned!!!!!

 

[DaneGer21]

The problem is that your probably a billionaire or at least a hundred millionaire right? That’s why melvin belli will take you to court for years if you modify your beat up old army truck and improve the brakes.
And then have an accident. Be very careful because there is a .0000000000000001% chance of that happening. You’ve been warned!!!!!

I guess I better repo all custom hot rods all over the world then; right?

I’d then in return sue Wilwood; you know the number one brake distributor for inferior parts…LOL

 

[rustystud]

I understand all the worry about modifying brake systems. The world we live in today is very litigious. That being said, if you use common sense and quality brake parts I don't see a problem. I'm not talking about using quality parts and then just "spot welding" the brackets on sort of thing. I'm talking about doing quality work. Something you would see on a "Hot Rod" car. If you're in an accident, the inspector will see that your system was built well and was totally able to stop the truck well within Federal and State specifications.
In fact, if your really worried about the legal implications. You can have your vehicle tested by your local State Patrol. At the transit agency we had brake force testers that we used on buses after every brake job. The results were recorded just in-case there was an accident, proving the bus was in compliance with Federal Safety Laws.

 

[fleetmech]

You can be sued if someone breaks into your house and hurts themselves...

One of the many advantages I see to a system like this is the use of non specialized components. The supply of airpaks isnt infinite, and the last ones were built a long time ago. Personally, I think it would be a waste to invest in big changes and add a second airpak at this stage.


Another method one could theoretically use that is close the the air force style is a pair of hydra-vacs. (fair warning, im not sure how available those are.) Chevy and a few others used this system into the 70s on single circuit juice brake medium duty trucks. In essence its the same as the stock deuce system but with a vacuum operated booster as opposed to compressed air. A dual master in place of the single and a pair of hydra-vacs and you'd have the basics of an a/f truck. A Ford super-duty vacuum pump and reservoir and you'd be good to go. Its a lot more plumbing, but gives you a full time hydraulic connection if thats what you want.

 

[rustystud]

You can be sued if someone breaks into your house and hurts themselves...

One of the many advantages I see to a system like this is the use of non specialized components. The supply of airpaks isnt infinite, and the last ones were built a long time ago. Personally, I think it would be a waste to invest in big changes and add a second airpak at this stage.


Another method one could theoretically use that is close the the air force style is a pair of hydra-vacs. (fair warning, im not sure how available those are.) Chevy and a few others used this system into the 70s on single circuit juice brake medium duty trucks. In essence its the same as the stock deuce system but with a vacuum operated booster as opposed to compressed air. A dual master in place of the single and a pair of hydra-vacs and you'd have the basics of an a/f truck. A Ford super-duty vacuum pump and reservoir and you'd be good to go. Its a lot more plumbing, but gives you a full time hydraulic connection if thats what you want.

The main problem with a "Hydro-Vac" is the lack of vacuum in a Diesel engine. Yes you can add a "vacuum" compressor as Chevrolet did on the early diesel engined vehicles, but it is expensive and not nearly as efficient as the Deuces "airpaks" are. Plus your now trying to add this vacuum pump to the engine. Not much room there as it is.
Plus the "Hydro-Vac" units are really scarce. I wanted to add one to one of my older trucks years ago and checked all the local wrecking yards and could find nothing. They haven't been made since the late 1970's. They weren't that common even then. They only came in Medium size trucks with a gasoline engine. Most of those trucks had Diesels then. The more common brake unit on Gasoline trucks was the Hydraulic driven power booster. Most Medium size trucks had air-brake systems by the mid 1970s. I know as I worked on plenty of them.
As far as legality goes, (like I mentioned) have the truck tested by your local State Patrol. That would put a stop to any litigation if there was an accident. After all the State Patrol approved it.

 

[fleetmech]

The main problem with a "Hydro-Vac" is the lack of vacuum in a Diesel engine. Yes you can add a "vacuum" compressor as Chevrolet did on the early diesel engined vehicles, but it is expensive and not nearly as efficient as the Deuces "airpaks" are. Plus your now trying to add this vacuum pump to the engine. Not much room there as it is.
Plus the "Hydro-Vac" units are really scarce. I wanted to add one to one of my older trucks years ago and checked all the local wrecking yards and could find nothing. They haven't been made since the late 1970's. They weren't that common even then. They only came in Medium size trucks with a gasoline engine. Most of those trucks had Diesels then. The more common brake unit on Gasoline trucks was the Hydraulic driven power booster. Most Medium size trucks had air-brake systems by the mid 1970s. I know as I worked on plenty of them.
As far as legality goes, (like I mentioned) have the truck tested by your local State Patrol. That would put a stop to any litigation if there was an accident. After all the State Patrol approved it.

Like I said, its just another option if someone wanted an original brake pedal and fully hydraulic system. The super duty vacuum pump is a smallish electronic pump, and one of the more robust things Ferd ever engineered. They used it on the powerstroke trucks to run hvac, hubs, and boosters on some models.

I find your idea to have the 'staties' inspect a vehicle enlightening; it really shows the difference between different parts of the country. On this coast, that would be somewhere between unproductive and actively detrimental...

 

[davidb56]

Like I said, its just another option if someone wanted an original brake pedal and fully hydraulic system. The super duty vacuum pump is a smallish electronic pump, and one of the more robust things Ferd ever engineered. They used it on the powerstroke trucks to run hvac, hubs, and boosters on some models.

I find your idea to have the 'staties' inspect a vehicle enlightening; it really shows the difference between different parts of the country. On this coast, that would be somewhere between unproductive and actively detrimental...

I had a vacuum pump on my Ford 1989 F250. I still got a spare somewhere, but not the truck. My 1992 F 450 (super duty) brake system ran off the power steering pump. I forgot what it was called. And my current 1994 F350 has a vacuum booster, but it is a gasser (460=plenty too). I really like both the air pack idea Fleetmech linked, or a system similar to the Ford F450, as I could later run a power steering unit off the pump too.

 

[Jbulach]

I had a vacuum pump on my Ford 1989 F250. I still got a spare somewhere, but not the truck. My 1992 F 450 (super duty) brake system ran off the power steering pump. I forgot what it was called…

Hydro-boost…

 

[rustystud]

Like I said, its just another option if someone wanted an original brake pedal and fully hydraulic system. The super duty vacuum pump is a smallish electronic pump, and one of the more robust things Ferd ever engineered. They used it on the powerstroke trucks to run hvac, hubs, and boosters on some models.

I find your idea to have the 'staties' inspect a vehicle enlightening; it really shows the difference between different parts of the country. On this coast, that would be somewhere between unproductive and actively detrimental...

I take it there is an "adversarial" attitude towards the State Patrol on the East Coast then.
Out here in Washington State we look open the State Patrol as a good thing to have around. They can be a pain when your caught speeding on the Freeway ! , but in general we like them. They do provide many services like inspecting your home-made trailer so you can buy insurance, and inspecting your crazy "Hot Rod" for street use.

 

[Mullaney]

I take it there is an "adversarial" attitude towards the State Patrol on the East Coast then.
Out here in Washington State we look open the State Patrol as a good thing to have around. They can be a pain when your caught speeding on the Freeway ! , but in general we like them. They do provide many services like inspecting your home-made trailer so you can buy insurance, and inspecting your crazy "Hot Rod" for street use.

.
Here in the North Carolina, they set appointments and will inspect vehicles. They are pretty good folks too. Willing and Interested is a nice way to describe them. Their official role isn't ticket writing and most of the guys who do that work do actually have some mechanical aptitude. Part of the License, Theft, and Weight Enforcement crew...

 

[fleetmech]

Ive been to North Carolina a bunch, I like it there!

Back to the brake system, disregarding the unanswerable question of American tort law, does anyone have any major concerns with a system like I described/ linked to?

The way I see it, the system gives us a major margin of safety in the form of dual circuit hydraulics, as well as a last ditch backup in case of complete air system failure. Also, the system can be completely tailored to the individual preference. If you want true double redundancy, dual single masters run by dual spring brake cans would give you two complete air and hydraulic circuits. Conversely, if your building a woods buggy and just want to replace a malfunctioning or less than available airpack, you could probably air operate the deuces stock master with parts from the local napa.

 

[rustystud]

Ive been to North Carolina a bunch, I like it there!

Back to the brake system, disregarding the unanswerable question of American tort law, does anyone have any major concerns with a system like I described/ linked to?

The way I see it, the system gives us a major margin of safety in the form of dual circuit hydraulics, as well as a last ditch backup in case of complete air system failure. Also, the system can be completely tailored to the individual preference. If you want true double redundancy, dual single masters run by dual spring brake cans would give you two complete air and hydraulic circuits. Conversely, if your building a woods buggy and just want to replace a malfunctioning or less than available airpack, you could probably air operate the deuces stock master with parts from the local napa.

I really don't see any advantage to going this route. My "AirForce" deuce with the dual master cylinder and dual airpacks works great. The master cylinder is still available for purchase and the airpacks are still rebuildable. Now you can just keep the dual master cylinder and go with a more modern airpack if you so choose. As far as the "Unobtainium" master cylinder bracket goes, just weld one up. With all the costs associated with the system your thinking about, you could easily afford to have a fabrication shop build you one or two.
Even the airpacks can be totally rebuilt with Stainless Steel sleeve inserts. Going this route would save you money and time and still be pretty much stock.
You can still stop a Deuce with total air system failure too with the factory system. Yes you well be standing on the brake pedal, but it can be done.

 

[patracy]

Air-Hydraulic Brake System with 1-3/4 to 2 inch Master Cylinder for Medium Trucks

Our Air-Hydraulic brake system uses an air-valve/pedal assembly to apply a remotely mounted air brake booster. It uses air pressure from a belt driven or 12 volt onboard air system to control the air-hydraulic booster, just like the brake system on super sized big rigs and buses, but it pushes a...

www.powerbrakeservice.net

I understand the misery of disappearing links, But most of the pictures I can find might be copyrighted, and I'd rather deal with our mods, so here is a link to a setup that looks like it would work in our rigs.

I'm interested in one of these myself. Mainly I just need to have a recommendation of what MC we could use. Because that's really nothing more than a brake can with the push rod cut down and a mounting plate made between it and the MC.