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Delta Dirt

actuate air brake cylinder hydraulically????

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Anybody ever tried actuating air brakes hydraulically--------thinking outside the box, but wondering why the same controlled hydraulic pressure would not cause the same reaction on the air cylinder (pot) to work air brakes.

Thinking about utilizing truck axle as a goose neck trailer axle. My truck has hydraulic brakes----no air.

Got some off the wall ideas-------all keyed around saving $$$$ and working with what I have and access to. (am familiar with electric and electric/hydraulic brake systems on the factory ordered axles)-------not familiar enough with the $$$$$ it takes to buy them!!!!!LOL

I never have torn an air cylinder (brake pot apart). What would be the downside???

DD

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It could be done ,take some experimenting , air brake cans are fairly long travel

so as the brakes wear the brake can has enough stroke to handle the slack,

Very easy to adjust air brake systems though , they use a worm drive slack adjuster,

Just thinking about it , the most difficult problem to overcome would be the volume of

brake fluid needed to actuate the cylinders that replace the air brake cans,

Word of caution do not ever.... ever... take apart a Maxi-brake style air can they have a spring

inside that has enough force to kill you , They can be taken apart with the proper special tools,

Interesting topic hope someone else chimes in

Kevin

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Exactly what is the Maxi brake style can????

Had wondered about volume------might want to set up separate master cylinder purely for trailer??

And-----my truck has the hydraulic park lock (pressure supplied by pump similar to power steering pump). Probably more volume here----maybe less pressure and actual hydraulic oil. Would require metering valve tied to brake pedal---but might be best bet???

Back in the '80s------I rigged up a vacumn actuated system for operating pure hydraulic brakes on truck axles under goose necks------worked like a charm. Utilized a booster when loaded----no booster when empty. Barely utilized the truck brakes.

What got me to thinking air brakes------I want to use a hvy duty front axle (10---12,000#)------and most in that range will have air brakes. Plus----the maintence costs seem so much cheaper.

All ideas welcome.

DD

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DD The Maxi brake is a spring operated park brake, released by air. Sounds like you have a Lucas Girling rear brake on your truck. It has a spring operated park brake, released by low pressure hydraulics.

Don't try to have a hydraulic trailer brake system directly connected to your truck brakes. A brake system designed for hydraulic brake fluid, and operated with a vacuum servo would be good.

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DD here is a youtube video with a short description of a maxi-brake can

Can you explain the system you built , sounds very interesting, I am thinking you used a GM system???

I have often wondered why they use overly complicated hydraulic drum brake systems, with finicky automatic

adjusters, leak prone wheel cylinders, when the "S" cam air brake systems are so reliable and easily serviced.

After the 18" snowstorm is over and done up here in Mass, I will get some real pictures of brake cans etc.

Kevin

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Thanks for the video------I was familiar with the "double pot" cylinders; but never the Maxi brake term.

In reality------the park lock works very similar to my Lucas-Girling system.

Will snap a picture of the vacuum actuated "aparatus"-------I still have one of the old grain trailers (cut down 600 Ford-----and I basically used parts that I had on hand). Probably could do same thing with the GM system-------but I didn't have them in "inventory"!!!

Try to get pic today-------bright and sunny------low of 22--24° last night. That' cold for us!!!

DD

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Kevin-----

Got some pictures on the vacuum acutated hydraulic brake system I put together (late 70's----early 80's??).

I utilized a conventional master cylinder with a vacuum booster cannister substituted in lieu of the brake pedal. This gave me "non-boosted" brakes.

Plus---------I mounted the conventional vacuum booster cylinder (from the truck that I had cut down). Had one vacuum hose feeding the master cylinder and another feeding the booster. I simply uncoupled the booster supply when empty.

I actuated all of this with a small hydraulic valve that opened the vacuum to the feed hoses when I barely mashed my brake pedal in the puller truck. I had a small cable hooked from the brake pedal to the lever on the vacuum valve (hydraulic)-------the lever was spring loaded so that it opened the feed of the vacuum as the brake pedal went forward; and closed as the stronger brake pedal spring returned the pedal back to top end.

The unique story on this "Rube Goldberg" design is that the small hydraulic valve came off of an old IHC one row cotton picker!!!

This was not my original idea---------but that of a friend in Arkansas who had cobbled up something similar; and I improved on it some. (don't remember exactly what his set up was----don't believe he was utilizing the booster) Seems like I had 6--700 psi on the straight master cylinder and 1,200+ psi off of the booster???

Hope you can follow the thought process with these pictures (and it is not really hooked to the old F-20!!!)LOL

post-1200-0-52655400-1388807120_thumb.jp

post-1200-0-44798700-1388807181_thumb.jp

post-1200-0-85116500-1388807260_thumb.jp

continued next page--------couple more pictures

Delta Dirt

Avon, Ms 38723

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continued from previous post----

post-1200-0-93973600-1388807668_thumb.jp

post-1200-0-53361500-1388808028_thumb.jp

We hauled 300---350 bu. on this old cut down van------------had another that I bought a grain bed for that would haul 400---450 bu on. Both had dump hoists under them-----the one in the pictures still has its hoist. We would occasionally just hitch them on the rear of a farm tractor if we were going straight to the bins----no worry with the trucks.

And-----------this is the "project roll back". I want to strip cab, etc and convert roll back to a Goose Neck pull trailer. (hope I am not condemmed the he!! for talking about cutting down a Loadstar!!!)

post-1200-0-20293700-1388808256_thumb.jp

Delta Dirt

Avon, Ms 38723

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Very Nice !! That's a fine bit of creativeness, B)

A bit of info, regular sizes of air brake "pot" or "can" diaphragms are called a "30" also a "36"

this refers to the surface area Sq Inches ,Sometimes they are smaller on front axles "20" i believe.

So a 30 size can at 120 psi air pressure develops 3600 lbs of pushing force, a 36 size makes 4320 lbs

Since the cans only operate on 120 lbs of air pressure it would be necessary to replace them with

some form of wheel cylinder/slave cylinder designed to handle hydraulic pressure.

This may help you determine the bore size of the slave cylinders that will be needed for proper braking.

As far as the type of system to make the cylinders work something similar to what you already built

should be fine as long as the available volume of fluid is sufficient.

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Ii keep thinking the ratio will be a real problem. Low pressure air with volume vs higher pressure oil with almost no real volume by comparison. Have to move a lot of oil to satisfy an air pot, and getting it "back out" might be slow... Would be easy to overload that diaphragm.

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Thanks to both------I am in the thinking/planning stages right now.

Had figured I would need to control (limit) pressure----do you think the rubber diaphrams would be effected by brake fluid or hyd oil????

Just thinking------thanks for the comments. Necessity was always the reason for invention!!!!!

......................still thinking; ----on a rear axle with the rock shaft action----a spring loaded hyd cyld could be substituted in place of the air pot pretty easy?

And----------if $$$$$$$$$ were not so hard to come by; some low profile factory axles sure would make it easy. Funny---------but I don't believe I would know how to drive on Easy Street!!!!LOL

DD

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Easy Street is way down on the left after hard knock blvd. and directly across from shuda wuda cudda way,

I keep programmin it in my nav says you can't get theyuhh from heeyuhh

Those brake rubbers get all spongy and fall apart when the air compressor lets a little oil vapor by..

Could always put an external return spring to help pull it back,

Were you thinking of something like a Porta-Power cylinder??

Good Luck

Kevin

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Reckon that would be similar------wasn't thinking porta-power; just negative spring loaded to give the return effect.

Really like your findings on Easy Street!!!

I am a farmland real estate broker/appraiser (with scrap iron running through my blood)--------I have run across some strange locations from time to time. Including "****'s Half Acre"-----and Easy Street;-----they both looked like good places to be FROM!!!!!

DD

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I will keep your profession in mind

Unfortunately I will have to sell my families home that my dad built in 1959 due to many reasons

the primary one being taxes ,I live about 20 miles east of Boston and the property taxes are out of control

some of the highest in the nation , where the house is located it is on 1 acre and under 3000sq ft house

taxes just creeped over 12k annually some of the residences in my town are well over 100k in taxes

,My wife and I are going to buy a small farm somewhere way south of here,

hopefully can get a little more privacy from yuppies and a little more land for the money,

Sorry for the hijack

Kevin

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No such thing as hi-jacking my thread------my mind rambles all over the board. I am still trying to catch my breath over your tax statement!!!!

How far are you from Salem???

That's one thing I really enjoy about the old tractor boards--------is being exposed to and learning what all is going on in other parts of the country. I am 70 yrs old and seemingly still learning something new everyday.

When you get too old to learn------it will be time to hang up your hat!!!!!! (note-----I didn't say anything about remembering)

DD

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I didn't figure there would be an oil problem? Seems like they should tolerate some oil given the compressor and catch tank and all that. Have no experience with them though.

12K is just sad.

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I'm a bit puzzled here. Sorry t is late night and there have been way too many late nights recently.

You want to cut off the truck and just use the back end? And it has air pots?

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Truck as is runs IH vac/hyd---------but need to replace booster, drums, shoes, wheel cylds.

Want to end up with low profile tandem on trailer. Got to thinking about hvy duty front axles------most of them run air brakes. And do away with as much un-needed weight as possible.

If could find 12,000# front axles with hyd brakes-----would just go with my "Rube Goldberg" set up. Probably some out there somewhere------

Ideally----would put a pair of torx flex axles under it.

May never get to it anyway-------I am getting real slow physically. Probably just need somebody to "talk me out of the old truck"----------but gotta have something to dream/think about. Seems like the old scrap iron relaxes my brain----and the business side of the computer strains my body and brain!!!

DD

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If you did end up using brake pots with oil instead of air , I think I could get you enough brake rubbers to last you a lifetime :)

We have an excavating job coming up this season in Watertown Ma, Just about 3 sq acres , the site was formerly owned by

B. F. Goodrich Tire and Rubber Co. and they used it for their dump !! We have to excavate down an honest 30 feet deep and

remove all the rubber sheets, shoe soles, millions of brake rubbers,forklift tires,and trimmings from every product they produced

since before WWII till about 1975 when they finally stopped them from burying it ,Apparently they produced millions

of raincoats and boots for soldiers When we run our TD15B over the site the

entire 3 acres moves and shakes , Then when you try to dig with an excavator the rubber stretches and wants to pull the machine into

the hole , I will be sure and get some pix of the action when we get rolling.

Kevin

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Sounds like an interesting project-----so where do you haul it for "re-disposal"???

De- contaminate site A and further contaminate site B???

DD

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Lets not get into specifics DD, political victory was declared and that is all we need to know.

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The rubber stinks to high heaven but according to all the testing ,and there has been a lot of it, it is not hazardous !!

It has to be removed for structural reasons to put buildings there , Large hotel, underground parking, etc.

It will be screened then trucked to Rhode Island facility then loaded on freight cars and pointed west

"coming soon to a town near you" as the saying goes lol

Kevin

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Delta, you could install an air compressor on your engine, and install a trailer spike and a relay valve and use the trailer brakes with air.You'd have excellent brakes plus the maxi's for parking.Not likely be DOT approved but brake fluid in the maxi pots wouldn't be either.

Cooter

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Good Idea!! and always nice to have air pressure handy for low tires etc.

Cooter whats a spike? some kind of control valve ,like the one on the right side

of steering column.

Kevin

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Yep, trailer spike is just a variable air flow valve.Older trucks just had them clamped onto steering column.I'd put a couple of air tanks on the truck for supply and one on the trailer with a R12 valve and you'd be good to go.Wouldn't be all that big of a deal to gear it up.Anything is better than juice brakes, in my mind anyway.

Cooter

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