I have a 2005 Sterling lt7501 crane truck and lately something in the air brake system has been freezing up. Twice in the last 45 days the truck was stuck on the side of the road because it wouldn't make air. We had to take the output hose off the compressor and get alcohol into the system for it to thaw out and build air again. Seems to take about 20-30 minutes of highway speed driving when the temperature is in the teens or less for it to start acting up. I heard the dryer discharge so I know it's atleast doing that. I have other trucks out in this same weather and they aren't freezing up so it must be something with this truck.
When was the last time the air cartridge was changed?
It doesn't have a spin on cartridge. It's just a big cylinder, doesn't look serviceable. If it is Im sure nothing has ever been done with it
(02-07-2018 )hhow55 Wrote: [ -> ]When was the last time the air cartridge was changed?
You have excessive amount of moisture in your air system. That points for inefficient air dryer filter . Drain your air tanks more frequently. Pour a lot of brake antifreeze/alcohol in and work it true the entire sistem . Replace desiccant filter/ dryer filter . Be sure air sistem is dry . Use designated brake antifreeze. If you have to , change filter on demand during winter.
Edit :
Ahhh , how come no desiccant on air brake sistem ???
I don't think there's a changeable filter on this dryer. It's a bendix AD9 If that tells you anything??
(02-07-2018 )tree98 Wrote: [ -> ]I don't think there's a changeable filter on this dryer. It's a bendix AD9 If that tells you anything??
It is . Is bolted to the body . Isn’t spin on . If You can’t find a filter only , there’s eBay .
AD9 are completely serviceable from the purge valve to the desiccant dryer in the middle. You just have to unbolt them and pull them apart.
Ok, we'll I think I'll just buy a new one this time and take the old one apart to see what it looks like inside so I'll be familiar with it for the future.
(02-07-2018 )Chamberpains Wrote: [ -> ]AD9 are completely serviceable from the purge valve to the desiccant dryer in the middle. You just have to unbolt them and pull them apart.
Is it an older style dryer with a sniffer bottle? Maybe it is empty if there is one.
You can put half a bottle to a full bottle of safetybrake brand directly in air tanks also, this helps a lot. How about your purge valve? Easy enough to change.
Is your compressor discharging oil? Check when you dump moisture out of your wet
tank with pull cord or when governor stops compressor when it sneezes.
Add more in discharge line. If all this doesnt work, service dryer.
Theres a small metal ring in there look carefully...a new one is included in the kit butf the old one looks good I just leave it. Clean up oxydized metal before installing new one for a good seal.