Deere Mack Posted March 24, 2011 Share Posted March 24, 2011 Hello I hope all is well. Started having troubles with air pressure not building. Its off and on as of now, more off than on. So trying to figure out my problem. I replaced the governor about 2 years ago, but was under the impression this only relieves the pressure at 120 psi and doesn't have anything to do with building air (not for sure). No leaks bad enough to cause it not to build at all. It will build at times but when it loses pressure it will not recover. Air Dryer? Any direction would be appreciated. Thanks, CpVin # 1M1AA18Y7TW061901 Quote Link to comment Share on other sites More sharing options...
Deere Mack Posted March 24, 2011 Author Share Posted March 24, 2011 Took off the regulator run some cleaner threw it and blew it dry, seems fine...popn' off at 120PSI. I really have to run up the rpm's or it will not build pressure. Run the up the RPM's(full throtle) and it seems to build at a normal rate and will hold pressure with engine off. Quote Link to comment Share on other sites More sharing options...
Rob Posted March 24, 2011 Share Posted March 24, 2011 Took off the regulator run some cleaner threw it and blew it dry, seems fine...popn' off at 120PSI. I really have to run up the rpm's or it will not build pressure. Run the up the RPM's(full throtle) and it seems to build at a normal rate and will hold pressure with engine off.I'm still recovering from "Momma" Bitch Slapping me last night for opening my mouth when she says I shouldn't have...... Other than that, I'm doing fine.Sounds like the unloaders in the compressor head are sticking partially open. Rebuild kits are under $20.00 and they are easy to install. Get some denatured alcohol to clean up the area(s) under the access covers on the compressor when apart. If a Midland compressor, be certain to lube up the valves and seals with the enclosed grease liberally.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
Deere Mack Posted March 25, 2011 Author Share Posted March 25, 2011 I'm still recovering from "Momma" Bitch Slapping me last night for opening my mouth when she says I shouldn't have...... Other than that, I'm doing fine.Sounds like the unloaders in the compressor head are sticking partially open. Rebuild kits are under $20.00 and they are easy to install. Get some denatured alcohol to clean up the area(s) under the access covers on the compressor when apart. If a Midland compressor, be certain to lube up the valves and seals with the enclosed grease liberally.RobThanks man! I feel your pain....dog training is a life long process.I appreciate the info. That seems like a cheap enough fix it shouldn't break the bank. Just need some denatured alcohol, I think I drank all mine, unless Tennessee whiskey will work, and a kit. First I'm hoping someone on here can look at my Vin and tell what compressor I have. Vin # 1M1AA18Y7TW061901 Quote Link to comment Share on other sites More sharing options...
Deere Mack Posted March 25, 2011 Author Share Posted March 25, 2011 Making threats to it did no good! Quote Link to comment Share on other sites More sharing options...
Deere Mack Posted March 25, 2011 Author Share Posted March 25, 2011 How often do the pressure regulators go out? This is a lowboy truck, so it sits around quite a bit, so I'm thinking this could be bad for them. Mine isn't but about two years old, but I've got a sneaky feeling. After all they are made in meckeco Quote Link to comment Share on other sites More sharing options...
Rob Posted March 26, 2011 Share Posted March 26, 2011 Making threats to it did no good!That is a "Midland" compressor. It is easy to service and the unloader rebuild kit comes with instructions. There will be a tag affixed to the compressor that will identify which unit it actually is.Most trucks are like women in nature. They know us men have needs only they can provide. Be nice offering love, affection, respect, and such, and the relationship will go far. Meet up with some psycopath, (typically Peterbilt) and have your life planned, charted, administered, and orchestrated with poor "service" throughout your time together.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
Deere Mack Posted March 26, 2011 Author Share Posted March 26, 2011 I replaced the air governor and it seemed to have fixed part of the problem, the compressor starts recovering around 90PSI. Now it is to slow on building pressure. I'm thinking its the air dryer, I'm almost certain it hasn't been serviced in many years. I've had the truck for alomost 4 years now and I sure haven't. Would this cause it to build slow? Didn't know exactly how they work or if they could clog up. Here's a pic of mine if anyone can tell me which one it looks like or anything helpful is always appreciated! Quote Link to comment Share on other sites More sharing options...
Rob Posted March 26, 2011 Share Posted March 26, 2011 Looks like a Bendix AD-9 to me. If the purge valve is not sealing in the bottom of the unit the air system will be slow to build and bleed off when the engine is shut down.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
rhasler Posted March 26, 2011 Share Posted March 26, 2011 Looks like a Bendix AD-9 to me. If the purge valve is not sealing in the bottom of the unit the air system will be slow to build and bleed off when the engine is shut down.RobYep, AD-9. I've heard/read stories of counterfeit desiccant cartridges being made with cat litter and such which will plug up almost immediately and cause the system not to build air. Something to watch out for when purchasing parts. Quote "Mebbe I'm too ugly and stupid to give up!" Link to comment Share on other sites More sharing options...
Rob Posted March 27, 2011 Share Posted March 27, 2011 Yep, AD-9. I've heard/read stories of counterfeit desiccant cartridges being made with cat litter and such which will plug up almost immediately and cause the system not to build air. Something to watch out for when purchasing parts.I always ran AD-4 series on my trucks if they had dryers. Never had problems with any of them but they were serviced with OEM Bendix kits yearly. I found this much less expensive than being broke down someplace. I have two trucks with AD-2 series and they work well also but are a bit expensive to work on. I installed new heaters yearly also.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
Deere Mack Posted March 27, 2011 Author Share Posted March 27, 2011 Thanks for the info and identification. I fixed every possible leak I could find but if it sits for a while it loses pressure. So are there rebuild kits for these? Would I be better off replacing it with a differnt model/kind? Quote Link to comment Share on other sites More sharing options...
Rob Posted March 27, 2011 Share Posted March 27, 2011 Thanks for the info and identification. I fixed every possible leak I could find but if it sits for a while it loses pressure. So are there rebuild kits for these? Would I be better off replacing it with a differnt model/kind?Rebuild kits are readily available. You can rebuild the assembly for about $60.00 or so and it takes about an hour. Another cause of system bleeding down could be the check valve, or valves installed into the wet tank inlet. If these don't seal the system pressure will discharge throught the compressor valves that are not designed to seal and hold back pressure. No need to replace this unit unless the main housing is corroded. You can buy the complete rebuilt baseplate assembly and basically everything would be new.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
Deere Mack Posted March 27, 2011 Author Share Posted March 27, 2011 thas great. It's buggn' me not having the air system up to par. After I get this corrected, I've got an air bag on the lowboy that needs to be replaced. Thought about useing a can of fix-a-flat on it. Quote Link to comment Share on other sites More sharing options...
Rob Posted March 27, 2011 Share Posted March 27, 2011 thas great. It's buggn' me not having the air system up to par. After I get this corrected, I've got an air bag on the lowboy that needs to be replaced. Thought about useing a can of fix-a-flat on it.You're asking for a whole lot of problems if you use that stuff. Replace it and be done.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
Deere Mack Posted March 27, 2011 Author Share Posted March 27, 2011 You're asking for a whole lot of problems if you use that stuff. Replace it and be done.RobRob, It must be gettn' close to your bed time. I was kiddn'........I sware though, if it were my grand dad, it would run threw his mind.. He'd be off to the dollar store for sure! Quote Link to comment Share on other sites More sharing options...
Rob Posted March 27, 2011 Share Posted March 27, 2011 Rob, It must be gettn' close to your bed time. I was kiddn'........I sware though, if were my grand dad, it would run threw his mind..Nothing surprises me. I've seen guys try to use a tire patch on a blown air bag. Fix a flat will plug the release valves used when you dump the air in the suspension.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
rhasler Posted March 27, 2011 Share Posted March 27, 2011 If the secondary air system (red needle) drops first and then the primary leaks off it could be because of the air bag leaking off the secondary system and then a check valve not fully seating and allowing the primary system air to bleed into the secondary circuit. Quote "Mebbe I'm too ugly and stupid to give up!" Link to comment Share on other sites More sharing options...
Deere Mack Posted March 27, 2011 Author Share Posted March 27, 2011 I'd have to be stranded to even use that stuff in a tire. I worked in my dad's shop when I was younger changing tires etc. and I hated when a tire came in with that stuff in it! Hated it ever since... Quote Link to comment Share on other sites More sharing options...
Deere Mack Posted March 27, 2011 Author Share Posted March 27, 2011 If the secondary air system (red needle) drops first and then the primary leaks off it could be because of the air bag leaking off the secondary system and then a check valve not fully seating and allowing the primary system air to bleed into the secondary circuit.That makes since, the lowboy bag isn't leaking too bad. The trailer is unhooked and I'm still having the same problem. Quote Link to comment Share on other sites More sharing options...
Deere Mack Posted March 27, 2011 Author Share Posted March 27, 2011 I have a quick connect on my secondary tank. If I add air to it(2ndry)with the shop compressor should it fill my primary too? Quote Link to comment Share on other sites More sharing options...
Rob Posted March 27, 2011 Share Posted March 27, 2011 I have a quick connect on my secondary tank. If I add air to it(2ndry)with the shop compressor should it fill my primary too?As I understand the system. No. The systems are separated by a check valve that precludes bleedback from secondary to primary. If you place your shop air charge valve into the primary supply system tank both systems will charge but not vice versa.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
Deere Mack Posted March 27, 2011 Author Share Posted March 27, 2011 Future reference for rookies like myself. This is a link to the Bendix AD-9 service data, it opens in PDF. CLICK HERE Quote Link to comment Share on other sites More sharing options...
rhasler Posted March 27, 2011 Share Posted March 27, 2011 thas great. It's buggn' me not having the air system up to par. After I get this corrected, I've got an air bag on the lowboy that needs to be replaced. Thought about useing a can of fix-a-flat on it.I misread this last night, missed the part about the bag being on the lowboy. The trailer air supply should be coming from the "dual air" circuit. I'll see if I can find a diagram. Quote "Mebbe I'm too ugly and stupid to give up!" Link to comment Share on other sites More sharing options...
rhasler Posted March 27, 2011 Share Posted March 27, 2011 This might help you out some, it's a little fuzzy looking but it should still be legible.CH and CL with Full Trailer Connection without ABS.pdf Quote "Mebbe I'm too ugly and stupid to give up!" Link to comment Share on other sites More sharing options...
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