| Author | Message | ||
| RJL Rating: |
What's the difference between the AD-2 and the AD-9 models? My 4106 doesn't have one, so. . . TIA, RJ PD4106-2784 Fresno CA | ||
| Chuck Newman (Chuck_newman)
Rating: N/A |
RJ, Check out http://www.bendix.com/products/ViewLiteratureDownloadMenu.do?key=AirDryers Also, anyone needing to know more about air brake systems in general, download the Bendix Air Brake Handbook. A wealth of information and diagrams. Chuck Newman Oroville, CA | ||
| Buswarrior (Buswarrior)
Rating: N/A |
Hello RJ The older AD-2 is just over 21 inches tall and 6 1/2 inches wide, the AD-9 is just over 14 inches tall and 9 1/3 inches wide. The AD-9 has more desicant and will give you more flexibility in locating it, due to the shorter height. Of importance, you have to have enough piping between the air compressor and the dryer for the air to have cooled enough that the desicant isn't damaged. I can't find the info on how far. Something like at least 6 feet maybe? (Stock install on the MC7,8,9 is up under the front axle, so there is plenty of pipe mileage to cool the compressed air.) Also, popularly, your bus may have an alcohol evaporator plumbed in somewhere. If you do, be sure it isn't upstream of your air dryer. You shouldn't introduce alcohol to the air dryer, it harms the desicant. The alcohol evaporator belongs downstream from the air dryer, if you continue to use it. There are also many newer dryer models that have spin on desicant cartridges, making servicing a very neat and quick job. For an in service bus, you would want to be sure you use a dryer that is "big" enough for the air needs of the bus, but a busnut typically doesn't run a duty cycle that a smaller tractor trailer dryer wouldn't do the job well. A smalller dryer just means the desicant will not last as long, but who amongst us will be wearing out the desicant? Don't forget to run a wire for the heating element in the purge valve. You never know when you and the bus might accidently find yourself in sub zero weather.... Just run it to a toggle switch somewhere if you are a warm weather follower. MCI wired it into the coach heat circuit - reasoning, if you need heat for the passengers, the air dryer needs heat for the purge valve. Swing past the local truck wreckers and see what you can find. happy coaching! buswarrior | ||
| john w. roan (Chessie4905)
Rating: N/A |
Go for the newer model as parts could be difficult to come by in the future for the older model. Make sure your air compressor isnt passing a lot of oil from worn rings before you install it as dessicant doesn't like it.Air dryers are great. | ||
| Tim Jones (Torquester)
Rating: N/A |
RJ, Buswarrior has some good info. I'd go for an AD-9. There is no need to switch the power to the purge valve heater it is thermostatically controlled. You can find re-manufactured units on sale sometimes at truck parts suppliers (seems like around $179.00 USD). If you have an alcohol evaporator get rid of it if you add the dryer, there is no need for it. The discharge line from the compressor should be installed with a downhill run to the dryer and the line should be copper for about six feet. In my opinion a dryer is the best thing that you could add to your system in order to make it safer and more reliable. The AD-2 uses a loose dessicant to refill and should soon become obsolete. The AD-9 uses a dessicant cartridge. I'd stay away from the new spin-on cartridge dryers for this application. hth, Tq | ||
| Jeff (Jeff)
Rating: N/A |
My AD-2 had a cartridge when I rebuilt it. My local heavy equipment supply company had the AD-2 dessicant cartridge on their shelf. There was a core charge on the dessicant cartridge. Jeff | ||
| Tim Jones (Torquester)
Rating: N/A |
Jeff, While it is true that you can buy a rebuilt cartridge for an AD-2, it is also true that the cartridge was rebuildable by the end user. Rebuilding required replacement of the loose dessicant material into the cartridge. This is not possible with the newer AD-9 dryers. It may be that Bendix has made the loose dessicant obsolete. If you would like conformation of these facts you can refer to the service manual here: http://www.bendix.com/downloads/service_data_sheet/082403.pdf hth, Tq | ||
| Jeff (Jeff)
Rating: N/A |
Thanks. I just know I took apart the bottom of my AD-2 air dryer. There was a wire for the heater I removed. Removed three bolts and then popped off a spring clamp. Inside there was a cartridge and an O ring that had a bolt in the center. It went the entire length of the cartridge to the top of the air dryer. It fell out. I wiped the insides dry and clean. Installed the new cartridge and replaced the bottom cap with a new O ring. Squeezed the spring back in place and tightened the three bolts and attached the wire. Jeff "Take Another Road" Member 4:10 Club Rustless not Busless in Buckroe 1988 TMC RTS-06 6V92-TA DDEC IV/V731 |
