I'm a road service mechanic in the Rockies with 30 plus years behind me & this was a pretty good video. Changing the desiccant in the dryer is a good idea that gets forgotten on many trucks & can lead to dryer failure or premature compressor failure due to it over-working. BTW the big hose on the compressor head is actually coolant not oil. If you see oil residue at the dryer, you either have a failing compressor or it's pulling oil from the intake manifold through the air supply line, in which case you need to solve the cause & rebuild or replace the dryer.
Awesome job men!!!! So many people need to know these things about the air compressor and purge valve its unreal. Thanks for helping all of us out here.
The Bendix dryers like that one are supposed to be serviced every year or every 2 years if it's one of the longer service life units. The desiccant cartridge needs to be replaced and the purge valve and check valve rebuilt. The desiccant absorbs the moisture in the air as it passes through and is purged out when the purge valve is opened allowing the air to move backwards through the filter and out of the purge valve. As the air compressor ages, the lubricating oil starts to get by the worn piston rings and into the air. The oil contaminates the desiccant making it ineffective. The purge valve on the dryer is held open until the air pressure drops to the governor's cut in pressure. There is a check valve on the output side of the dryer so only the air in the dryer is purged. Some dryer systems have a different purge system that does use some system air to purge the desiccant. Some dryers use an extra tank to supply purge air. Those often are never serviced because they take too much time. Many places replace them with a rebuilt unit or a different brand that has a spin on filter that is much easier and quicker to service, like a WABCO unit. We serviced the air dryers in the summer to make certain the air system was dried out before the weather got cold enough to freeze the brake system. Once there is moisture in the system, it is difficult to get it out. We found it much better to spend the money servicing the dryer every year to avoid having problems on the road. Having to tow one vehicle costs more than it cost to service the dryers on thewhole fleet.
Hey JC... I heard you. But, just saying, I've rebuilt more than a few Bendix and Wabco purge valves. The only parts that usually go bad are the O-rings and disk, and they're cheap. New valves are usually $100+ (much more if you're buying a Bendix part in a Kenworth package).
Good explanation on everything! Glad the cleaning worked, but don't blame you one bit for wanting to replace. The parts are cheap enough it's not worth risking getting stuck on the road over. Thanks for the video!
This was a great video J.C. I’m looking for an M923 truck which will be my first foray into air brakes. Knowledge like this will become invaluable for me in the future I’m sure.
Most air dryers have a filter that most people never change. I have had the filter plug up and not let the purge valve close. When putting the purge valve back together use vaseline or light oil on the o rings. And when you change the purge valve change the filter
Nice fix. Seems it didn't need much but a cleaning. Just some easy labor. I can understand you wanting to replace it and driving it to make sure the problem doesn't reoccur. As always nice work.
It looks like it might be time to replace that whole dryer assembly, or at least change the cartridge inside. That black gunk shouldn't be making it to the purge valve. Those Dryer's should have the cartridge/filter changed yearly. My Cost on a AD9 Air Dryer is 112.99. Rather change the whole thing, as opposed to fighting with the filter and the purge valve... Just some thoughts from a fellow Big Truck owner. :) Thanks for sharing the video! Looks like it has helped quite a few people so far
i have not found the dryer that cheap but it is not much more than the purge valve by itself. i will replace the entire dryer. where did you find it that cheap?
@@j.c.smithprojects my local Pete dealer. Martin's Peterbilt. It's a trp unit, not bendix but still great quality. They had em on special in October. It's just a bendix AD9 dryer. Pretty universal. I can msg my parts guy and get a current price for ya.
Good job explaining J . C good job I’m having same problem with my 2011 cascade I put new air dryer on ..and what it was doing when I get up farther in the north we’re it’s cold my brake light come on and then ..I have to pull over but it’s some wrong with my heater cord on the air dryer ..I can’t get no volts to it
Good explanation. However the compressor doesn’t actually free wheel like it would if operated by a clutch. It’s actually always pumping but when the governor has the reed valves closed the air that’s compressed on the upstroke expands on the down stroke so in theory no “work “ is being done.
Good fix JC, and great explanation of how the compressor unloads at designed pressure. Hope your day got better after this video. Work safe! Doug@ the "ranch"
Well I got my air brake system video i asked for great info jc that style air dryer is a bendix ad9 and the compressor is also the newer style bendix that replaced the tu flo 550 .
You can get rebuild kit for those but I recommend new soon possible. What happens in Arizona is that valve get heated up and it will throw that purge valve on the ground. Then you have to bypass to get home. $100.00 fix in the older trucks.
The air compressor governor does two functions. In your application it opens the unloaded valves after it builds the correct air pressure and it sends a air signal to the air dryer to purge air.
@@willmann30 if you have a constant air purge at frequent intervals you have a air leak between your unloader valve and your air purge valve and you probably can’t hear it when the engine is running. You won’t see the air pressure drop on your air gages when this happens. Shut your engine off just after your air dryer purges and look for a air leak between your air dryer and air compressor. You can also charge your signal line to your purge valve on your air dryer with shop air and engine off so you can hear the air leak. I hope this will point you in the right direction.
I won't rebuild the purge valves either, thier not that expensive , I'd rather pay the money for a new valve than be stuck, I usually replace the governor also, people don't drain there air tanks enough, they can get stuck open and you won't make any air.
Ok, l know more than l did before (l thought the whole assembly had to be removed from the truck & cleaned out) l'm not understanding about the cruise control - the air dryer on the Mack Granites we have gets it's orders from the fan clutch & air conditioner (that's what l was told) and we go through fan clutches on a somewhat regular basis down here
My 2006 Columbia will build air to 150 psi once I put it in gear to drive the alarm buzzer will come on and the air drop between 120 100 psi still be hearing the buzzer alarm can someone helpe here pls.
I am trying to figure out whether you have done this before, or if you have a copy of the factory service manual. You know an awful lot about the air brake system, that's for sure. 😏
I'm a road service mechanic in the Rockies with 30 plus years behind me & this was a pretty good video. Changing the desiccant in the dryer is a good idea that gets forgotten on many trucks & can lead to dryer failure or premature compressor failure due to it over-working. BTW the big hose on the compressor head is actually coolant not oil. If you see oil residue at the dryer, you either have a failing compressor or it's pulling oil from the intake manifold through the air supply line, in which case you need to solve the cause & rebuild or replace the dryer.
Awesome job men!!!! So many people need to know these things about the air compressor and purge valve its unreal. Thanks for helping all of us out here.
The Bendix dryers like that one are supposed to be serviced every year or every 2 years if it's one of the longer service life units. The desiccant cartridge needs to be replaced and the purge valve and check valve rebuilt. The desiccant absorbs the moisture in the air as it passes through and is purged out when the purge valve is opened allowing the air to move backwards through the filter and out of the purge valve. As the air compressor ages, the lubricating oil starts to get by the worn piston rings and into the air. The oil contaminates the desiccant making it ineffective. The purge valve on the dryer is held open until the air pressure drops to the governor's cut in pressure. There is a check valve on the output side of the dryer so only the air in the dryer is purged. Some dryer systems have a different purge system that does use some system air to purge the desiccant. Some dryers use an extra tank to supply purge air. Those often are never serviced because they take too much time. Many places replace them with a rebuilt unit or a different brand that has a spin on filter that is much easier and quicker to service, like a WABCO unit. We serviced the air dryers in the summer to make certain the air system was dried out before the weather got cold enough to freeze the brake system. Once there is moisture in the system, it is difficult to get it out. We found it much better to spend the money servicing the dryer every year to avoid having problems on the road. Having to tow one vehicle costs more than it cost to service the dryers on thewhole fleet.
Hey JC... I heard you. But, just saying, I've rebuilt more than a few Bendix and Wabco purge valves. The only parts that usually go bad are the O-rings and disk, and they're cheap. New valves are usually $100+ (much more if you're buying a Bendix part in a Kenworth package).
Dude, thank you. Very informative. Its great when people explain how things work.
Good explanation on everything! Glad the cleaning worked, but don't blame you one bit for wanting to replace. The parts are cheap enough it's not worth risking getting stuck on the road over. Thanks for the video!
its far easier and cheaper to change it now than over paying later when i am stuck. especially now that winter has arrived in full force!
Now I know where the ‘Nice Hiss’ comes from.
This was a great video J.C. I’m looking for an M923 truck which will be my first foray into air brakes. Knowledge like this will become invaluable for me in the future I’m sure.
Dude. That helped incredibly. Im having an issue with the purge valve. I can hear it. Im a new schoolbus owner so its all new. Thanks
Good job, thanks for the explanation! I have several air leaks; they are really hard to find unless they are fast leaks.
Most air dryers have a filter that most people never change. I have had the filter plug up and not let the purge valve close. When putting the purge valve back together use vaseline or light oil on the o rings. And when you change the purge valve change the filter
Thanks for taking your time going over every thing
Another great informative video. Thank you for explaining the fundamentals of how an air brake system works
Thanks for taking some of your precious time to share your knowledge about it ! Its really helpful 👌😎
absolutely helps I own the exact model. I'm thinkin maybe I should have one on hand in the truck . Thanks for the video
Nice fix. Seems it didn't need much but a cleaning. Just some easy labor. I can understand you wanting to replace it and driving it to make sure the problem doesn't reoccur. As always nice work.
Great video and Repair JC
Good job explaining the problem and how to fix it
Thanks that exactly the problem I have with my 2009 FR series 60 engine 14 L thanks again for your help
Well done Sr thanks 👍👍👍
This was a very great video. Help me get out of the gym. Appreciate you.
It looks like it might be time to replace that whole dryer assembly, or at least change the cartridge inside. That black gunk shouldn't be making it to the purge valve. Those Dryer's should have the cartridge/filter changed yearly. My Cost on a AD9 Air Dryer is 112.99. Rather change the whole thing, as opposed to fighting with the filter and the purge valve... Just some thoughts from a fellow Big Truck owner. :) Thanks for sharing the video! Looks like it has helped quite a few people so far
i have not found the dryer that cheap but it is not much more than the purge valve by itself. i will replace the entire dryer. where did you find it that cheap?
@@j.c.smithprojects my local Pete dealer. Martin's Peterbilt. It's a trp unit, not bendix but still great quality. They had em on special in October. It's just a bendix AD9 dryer. Pretty universal. I can msg my parts guy and get a current price for ya.
Great Video.
Great job explaining
Good job explaining J . C good job I’m having same problem with my 2011 cascade I put new air dryer on ..and what it was doing when I get up farther in the north we’re it’s cold my brake light come on and then ..I have to pull over but it’s some wrong with my heater cord on the air dryer ..I can’t get no volts to it
Thanks for explaining that. Really helpful
This video is really cool. I just got done fixing a similar problem with the exact same truck at school
Thank you very much! It helps me🙏
Good explanation. However the compressor doesn’t actually free wheel like it would if operated by a clutch. It’s actually always pumping but when the governor has the reed valves closed the air that’s compressed on the upstroke expands on the down stroke so in theory no “work “ is being done.
Just started having this problem on my 91 F350, thanks for the info!
you know...i have been following your build since the beginning. glad this came at a good time for you. are you near binghamton?
J.C. SMITH PROJECTS thanks for following along. Yeah I am right in Binghamton.
when i owned a trucking company, I use to deliver to north norwich motors
I learned a lot, thank you
Nice tutorial on the air dryer function. And ideas for trouble shooting.
Some good information 👍
Great job thanks
Great explanation, ty!
Great video
Good job 👍🏽
Thank you so much for this video! That what was wrong with mine and I followed your example to the very end. Thank you!
that is great. it is exactly why i make videos. i hope to help others who might be experiencing the same issue.
Great video. Thank you.
Good fix JC, and great explanation of how the compressor unloads at designed pressure.
Hope your day got better after this video. Work safe!
Doug@ the "ranch"
Understood thanks big help, cheers .
Good to know! Thanks!
Nice truck, good motor and trans! Company truck dashboard. It will make someone a good truck!
I am using this one. someone will have to wait until i am done with it. might be a little while.
Great job.. thx for posting.
Well I got my air brake system video i asked for great info jc that style air dryer is a bendix ad9 and the compressor is also the newer style bendix that replaced the tu flo 550 .
Good vidio mr. thanks for letting us know that trick
Good job bro. Thanks you ,
Gracias amigo
💯💯💯💯💯 thanks for sharing
Thank you for the information and education.
You can get rebuild kit for those but I recommend new soon possible. What happens in Arizona is that valve get heated up and it will throw that purge valve on the ground. Then you have to bypass to get home. $100.00 fix in the older trucks.
thanks ,, great work
Thanks for this video! I didn’t have to have my truck towed.
What did perg cost you when you bought it?
air dryer wire what are they used for or The purpose mines was completely off
The air compressor governor does two functions. In your application it opens the unloaded valves after it builds the correct air pressure and it sends a air signal to the air dryer to purge air.
What if it purges every 2 minutes on first start up but you have absolutely no air leaks at all?
@@willmann30 if you have a constant air purge at frequent intervals you have a air leak between your unloader valve and your air purge valve and you probably can’t hear it when the engine is running. You won’t see the air pressure drop on your air gages when this happens. Shut your engine off just after your air dryer purges and look for a air leak between your air dryer and air compressor. You can also charge your signal line to your purge valve on your air dryer with shop air and engine off so you can hear the air leak. I hope this will point you in the right direction.
Thanks that was so helpfull
I can make some good money with that truck great combo old Detroit series 60
good reliable engine right there. so much better than the junk available today.
The Series 60 sounds good.
it runs very well 455 hp gets it down the road just fine.
JC I have an air pressure problem is there a way we can visit about it?
Have sane problem today. I appreciate it!
I won't rebuild the purge valves either, thier not that expensive , I'd rather pay the money for a new valve than be stuck, I usually replace the governor also, people don't drain there air tanks enough, they can get stuck open and you won't make any air.
Freightliner m2 106 really worth double the price of an international MV ? Class 6 26,000 lbs
M2s are better trucks. Internationals are cheaper and have a lot of issues.
I’ll bet the dryer element has not been changed for years. The contaminates have started getting in the valve.
Ok, l know more than l did before (l thought the whole assembly had to be removed from the truck & cleaned out) l'm not understanding about the cruise control - the air dryer on the Mack Granites we have gets it's orders from the fan clutch & air conditioner (that's what l was told) and we go through fan clutches on a somewhat regular basis down here
i dont know anything about those mack granites. i have never owned one. they are not very popular around here.
a new cost $350 a all filter it's better to buying a new it will give you same problem to much dirt inside good luck man
My 2006 Columbia will build air to 150 psi once I put it in gear to drive the alarm buzzer will come on and the air drop between 120 100 psi still be hearing the buzzer alarm can someone helpe here pls.
The buzzard is your low air pressure switch
What if the secondary tank builds air but not your primary
My 2006 freightliner it build air on and off One day build air quickly other day is not
I am trying to figure out whether you have done this before, or if you have a copy of the factory service manual. You know an awful lot about the air brake system, that's for sure. 😏
i have had trucks with air leaks before but this was my first purge valve issue.
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Second first
You talk god damn much 5:16
you complain too much