Looking for Alcohol Evaporator Kit for M35A2

[greenjeepster]

I don't see how that intake system works... if you put a vacuum gauge on that port you will notice that that is a surge port...not vacuum. If unplugged it draws air out and pushes it back in. I do not logically see any way that it will draw alcohol vapor into the system. Maybe that is why they did away with that system?
All evaporators I have ever seen until now has been a Pos pressure system like what M16ty described.

My current truck does not have an evaporator on it and although I have not had it long it has been in the teens and single digits for the last few weeks and I have had no problems with freezing. Drain you tanks down when you shut the truck off and close the valves after wards and you should not have moisture in the system to freeze.

 

[Srjeeper]

There seems to be some confusion here between a Alcohol Evaporator System and a Alcohol Injection System

The Evaporator System draws VAPOR ONLY into the compressor thru it's intake. It is not a pressurized system.

The Injector system injects metered amounts of liquid directly into the air brake system after the compressor. This system is pressurized.

They both work equally well when used on the systems they were designed for.

 

[greenjeepster]

I understand the system just fine. Look at the picture of the intake system and look where it is connected on the intake. Then take a vacuum gauge and hook it up to that port and see what it does when the compressor is started.

It will surge. It would be a great place to hook a milking machine to milk a cow, but it is a terrible place to plug in a alcohol evaporator. It is similar to taking a ball and putting it into a piece of pipe.... Then tip the pipe one way and before the ball gets to the end tip it back the other way....

If somebody can explain how this is working please do... I am all ears

 

[Srjeeper]

It's that very back & forth pulseing, that creates bubbles inside the container, that creates the atomized vapor that is then drawn into the compressors intake along with the air it compresses.

 

[ida34]

If your intake is pushing air back out then your compressor is bad. If the intake is pulsing that is not a problem. Inside the compressor there are reed valves that make sure the direction of the air is one way coming in from the intake side and pushing out towards the tank side. If a compressor is working properly it has to take in air. When it does so it also takes in a small amount of alcohol vapor. The pulsing is tied to the timing of the compressor. It has to pull then push. for the time it is pushing it can not pull in more air. A twin cylinder should show a more consistent vacuum and this is what I have but some trucks have a single cylinder compressor and this would show a more pronounced surge. Maybe your truck has a single cylinder compressor. My main point is, the intake side has to draw in air or the compressor is not working. It will draw air from all open ports on the intake and of course will take smaller amounts from smaller orifices.

 

[Srjeeper]

When the system is calling for air there should be no pulse, only when the air pressure in the system has reached 120 and the gov. shuts off.

 

[greenjeepster]

When the system is calling for air there should be no pulse, only when the air pressure in the system has reached 120 and the gov. shuts off.

So then the evaporator only works when the system is compressing air?

 

[saddamsnightmare]

January 12th, 2010.

Correct, Greenjeepster:

The air compressor on my M35A2 is a single cylinder unit whose unloading valve is controlled by the governor. When the system reaches shut off pressure the unloader opens so the compressor will not draw and compress air. When the system governor reaches the low air pressure cut in point, it closes the unloader and the compressor draws in and compresses air.
To get alcohol into the system the other day to initially unfreeze the tanks, I allowed it (the compressor) to draw several capfulls of alcohol through the filter port, and when it was pumping it drew in as much as I could reasonably feed it. The diagram in the TM9 parts book does show it plumbed to the 1/8"NPT port on the top of the filter casting, and there would be sufficient draft there to pull alcohol vapors if the main port can pull alcohol liquid.
Regrettably the price of the evaporator kits on here is almost more then I can justify at present, though they are slightly less then new civillian units, but I drain the tanks several times a day normally, but if the truck is running in 25*F and below weather, the drains will freeze without alcohol in the system, then you are plucked..... Over the road trucks and railroad locomotives all have a similar system to keep the air brakes working in winter....

Hopefully we have hammered out the details.... now to find a serviceable unit.

Cheers,

Kyle F. McGrogan

 

[greenjeepster]

Actually you are not plucked.... your truck has hydraulic breaks even without air. If the air brakes freeze on an airbrake truck it causes the spring brakes to engage and the truck quickly comes to a stop and cannot be moved until the air system is thawed out... On a deuce you will have less boost to the brakes, but still have brakes and no spring brakes to worry about...

Save your money and drive on.... I am not sold on the intake system. I would spend the money on a positive pressure system and retrofit if there was a need for an evaporator on one, but I don't see the need.

This would be the best option if you absolutely wanted one: http://cgi.ebay.com/ebaymotors/Hald...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

 

[cbvet]

Having just experienced a frozen compressor, I think the cheap & simple evaporator is a great idea.

My own fault. I started the engine without clearing away the snow covering the mushroom. After about 10 seconds the compressor stopped turning. Frozen.
Got it into my shop & warmed it up. Compressor's fine.
It seems possible that driving in a heavy snowstorm, the compressor could draw in moisture & freeze.
The alcohol evaporator would probably prevent that.
I know, there are still brakes without air pressure. But this simple addition could save a belt and/or compressor.
I've driven a lot of miles in cold weather & snow without problems, but this looks like cheap insurance.

 

[saddamsnightmare]

January 11th, 2010.

Gents:

I am fairly familiar with the deuce, having experience with M135/M211's and the present M35A2, of the three types I prefer the latter. Yes you still have brakes with the air system frozen up, what you don't have are quick reacting brakes and a hard steering truck as the air o matic won't do too well either without air. I admit I am currently in an area that doesn't get this cold often, but my next posting could be as far north as Anchorage, Alaska, or West Virginia, both places known for getting fairly cold in the winter. Ergo i gotta fix the starter problem , get cab heat and an evaporator unit, because air assist is very good.
CBVET, if you look at "Saddam's Nightmare" in my icon or avatar (whatever the !@#$$@#) it is, you will note the 4" elbow as a field mod applied to the mushroom, many units in cold weather/snow areas applied these to get the mushroom outta the snow. It also keeps the filter drier in rain and a dry filter is a happy filter. I think this mod ran me about 4 to 6 bucks with the clamp. You must be pulling your air brake air through the crossover hose from the compressor to the air filter cannister. I have thought about applying that mod, usually seen in the fording kits, to keep the air brake compressor from having to draw dirty air that passes through the radiator (a lot of sandy roads around here, you know).Thanks again, gentlemen,

Cheers,

Kyle F. McGrogan

 

[IMA944T]

Ok how about this. Line coming from air filter housing going to simple bottle. The line would have to go almost to bottom of bottle which would be below the level of antifreeze that would fill bottle. The another line would come from compressor to the top of the bottle but barley go through cap. This line would never come in contact with the antifreeze. When compressor draws air in, it would have to come from filter housing through the line which the air would be drawn through the antifreeze then through the line going to the compressor.
Simple yet effective. No postive pressure so the bottle could be very simple glass or plastic.

 

[IMA944T]

Anybody know how much CFM the compressor puts out?
Going to try my Idea next week unless someone comes up with a Do not do it reason.

 

[greenjeepster]

Should work. The bubbling from the air passing through the anti-freeze will vaporize some alcohol and take it to the compressor. I think it would be smart to turn your pop of valve down to about 80 lbs so that the compressor is drawing air constantly on cold days. That will keep a steady supply of alcohol headed into the system.

 

[cranetruck]

The original vaporizer system appears to work well, was original equipment on the m656/xm757 series (1969).
I have had mine for years and it consumes about a pint of alcohol every 1,000 miles.
The CFM of the compressor is about 7...

 

[IMA944T]

What did the guy on the earlier post pay for his OEM unit? Looks nice but I think the simple design would work for most situations. Moneys tight for me.

 

[saddamsnightmare]

January 13th, 2010.

Thanks Cranetruck, The CFM on the single cylinder compressor did seem a bit anemic when combined with the service tank CID capacity. I have noticed that a lot of maneuvering at low speed will allow the Air O Matic to outrun the compressor output and set off the low air pressure alarm. I have been thinking of plumbing in another set of airbrake tanks and parallelling them to the service reservoir just to get some reserve capacity for maneuvering at low speed. Still, I would not be without the Air O Matic by any choice.

Cheers,

Kyle F. McGrogan

 

[mbarber84]

What did the guy on the earlier post pay for his OEM unit? Looks nice but I think the simple design would work for most situations. Moneys tight for me.

If you are referring to mine, I believe I paid just over $110 for it after shipping. Purchased frm Ebay. I didnt think it was too expensive, as the kit comes with everything needed including easy directions. It fits just like an NOS kit should, and it serves the purpose. One point, the original directions call for the use of pure Methanol. I purchase my methanol second-hand from a friend who home-brews good biodiesel, so it can be had. If you need any other info, dont hesitate to ask. Might want to keep checking on ebay, they pop up from time to time.

P.S. - Take extra care when installing the bracket and assembly directly to the compressor, as I had to re-try several times. Make sure you load up all seal areas with a good silicone or similar gasket material, and give it plenty of time to seal and set!

MB

 

[mistaken1]

Another wrinkle:

From this page:
http://www.bendixvrc.com/itemDisplay.asp?documentID=5147

Bulletin No: PNU-120-000 Effective Date: July 11, 2008 Cancels: N/A Page: 1 of 1
Subject: Bendix® Alcohol Evaporators and Injectors
Bendix Commercial Vehicle Systems LLC discourages the use of alcohol in the air brake system as a means of
preventing a freeze-up and will consider the Bendix® air system components’ warranty void if analysis shows that
alcohol was added to the air brake system. Please see Technical Bulletin TCH-008-042 for details.
In keeping with this position, the following part numbers will only be available until the current supply is depleted,
at which time they will be considered obsolete with no future orders filled.

 

[mistaken1]

double post