Air Dryer for an M35A2

[shootiniron]

Been looking and really no joy yet.Where to find an air dryer for the A2?What about the cost?Any ideas as always will be greatly appreciated.Thanks!

 

[gimpyrobb]

Lots of them on egay. Just not sure which one to use.

 

[Rustygears]

If you are looking for one to cover the entire truck air system, the stock one used on the A3 is the commercial 'Haldex' model 'Pure Air'. These are very common on commercial trucks and are simple and rugged as well as designed for both extreme heat & cold.

They are available through many discount truck supply sites and flea bay. The automated self-cleaning feature is really nice.

 

[Alredneck]

I asked about a Bendix unit but they want 3-400 bucks and I though that was ridiculous. I do reccomend one but would comb the junk yard and find a good used one. Also the make sure your govenor is free from gunk and working with in its PSI ratings. The one on my deuce and M54s look just like the bendix govenor on my International. I think the new one for my International when we replaced the air compressor in it was 75, the compressor was almost 600. Fun Fun when You have truck trying to make money off them! And now it sits with a blown motor!

 

[shootiniron]

Haladex "pure air" 24v is the one right?

 

[WillWagner]

Haladex "pure air" 24v is the one right?

You only need to worry about that if you want the heated flavor.

 

[gimpyrobb]

What does the heat do? I know I got a refrigerated compressed air dryer for my shop air and that cold makes the condensation drop out. I don't see how heat can help.

 

[m-35tom]

the drain area is usually heated on the pressure drop type of dryer but i have never had a problem with no heat on mine.. it just keeps the moisture from freezing on really cold days. you should bve able to find a used unit for $50.

tom

 

[Blood_of_Tyrants]

From what I know about air dryers, they come in two flavors.

There is the mechanical type that uses refrigeration system to cause the moisture in the compressed air to condense on some refrigerated tubing (the compressed air is circulated passed the tubing). The moisture is gathered at the bottom and on the better units is automatically dumped.

Then there is the desiccant type which means that the air passes through a chemical that readily absorbs the moisture. However, when the chemical is "full" of moisture, the way to get it out is to heat it for a period of time, usually with a built in heater. Since this means that the dryer will be out of service for a period of time, usually several hours as the heat drives out the moisture, this isn't an option for many people. But it is a good option for the hobbyist as it is much cheaper than a refrigeration type dryer.

 

[m-35tom]

but we are talking about vehicle air dryers and neither of these are used. the only common type is the pressure cycle type where beads readily absorb moisture from pressurized air and release almost all of it when the pressure suddenly drops.

tom

 

[WillWagner]

To service, spin a new element on it.

 

[Rustygears]

The replacement filter kit has both spin on filter and new dessicant cartridge as well as a few other items. It takes about 10 minutes to replace these items and no special tools. Once done, you essentially have a completely new dryer, except for the housing. If you get a used one cheap, put the replacement kit (available multiple places selling OTR discount truck supplies) and get a factory fresh dryer system. I did this on my A3 and I no longer have any moisture in my wet tank when I open the purge valve.

 

[shootiniron]

Is there a certain model that will work the best or just any 24v unit?

 

[Rustygears]

The Army used the Haldex "PureAir' as the stock 24V model (heater included) in the 'A3. That is a very common commercial unit used on many big rigs. It's really bulletproof. I've seen them on flea bay for under $100 NOS. Probably available elsewhere surplus as well.

 

[gimpyrobb]

Bringing this thread back.

I ended up getting one of the A3 type air dryers. The guy selling it was worried that it is listed in the CTIS(should use lots of air) section of the A3 TM. In all of the searching I have done, NONE of the air dryers for trucks list a cfm. Is this a concern I need to worry about or not. Everything I have read leads me to "NOT", but I wanted to be sure.

 

[quickfarms]

If the air dryer feels heavy when you pick it up it is probably pluged with moisture

 

[rosco]

The only trouble fre air dryer is the alcohol snifer. They are adequate for all weather conditions, even the extremes that we encounter here in the North. The one that often comes with the M35A2 is adequater and trouble free.

 

[gimpyrobb]

I never thought about that. Will the alcohol system give the air dryer fits?

 

[rosco]

The snifer is all that you need! Drain your tanks daily. Go to a heavy truck shop and get the "Pull Cord" type drain cock, so you don't have to crawl under there. The only modification to the stock Deuce snifer, is to wrap some duct tape around the jar and the metal top, so that jar doesn't rattle loose, and fall off.

 

[cranetruck]

Agree with Rosco...why add components that will make the operation of the truck more dependent on the batteries... besides, it's not a bad idea to use an alcohol evaporator along with you "dryer" too.
My xm757 has 3 stages of air tanks and there has never been any moisture in the 3rd tank in my experience. It came from factory with an alcohol evaporator/vaporizer.