Anybody know what type of compressor we have on a 1999 u320 coach? There are different parts numbers for the haldex air dryer. Evidently this type of compressor needs a return line to manage the oil that comes off the compressor. I'm curious if I'm just putting the wrong air dryer on?
A '99 should have a SS series compressor. It may be the SS296E as that was standard back then. If you are ordering a dryer for the QE series then you will have a problem as they are totally different. They did make a 296 in the QE series so it can be confusing. To make sure you need to look at the blue tag on the side of the compressor to be for sure.
Mike
Thanks. Here's my problem if you've been following my other thread. I had problems with the air dryer, not purging and the PSI pegging. At 150. I replaced the governor. No change really. Finally took out the air dryer and did the bypass. I noticed that there was a lot of oil in the communication line from the D2 governor. That seemed to work and my pressure's on the drive were between 120 and 130. I ordered a rebuild kit for the air dryer from find it parts but did not get the bottom part just the top. My bad. Rebuilding it yesterday. Put it back in and did not get a purge. I wasn't able to drive the coach but at 1,500 RPM I was able to get it to 130. DA33100X was the part that I installed 9 months ago in Arizona. It didn't last a year. In researching I saw that video about a different type of air dryer needed for the holset type e compressor and started to have a little panic attack because I have ordered another DA33100X from Napa and a picking it up in the morning. I don't want to throw good money after bad and put in the wrong thing. The original air dryer did not have a communication line between one side and the other so I'm thinking I'm okay but still worried. So the question is is how much oil should there be coming through that communication line from the D2 governor to the air dryer? What happens with that oil?
The more I research the whole air system the more intrigue I am. But for now, I just want to be able to drive down the Mazatlan and start sucking down some margaritas on the beach without having to worry about it too much.
It's kind of hard to see the tag on the compressor. It's probably full of dirt too. Too. I'll try squirting some brake cleaner on it tomorrow. Just don't have a whole lot of time....
Bob
It sounds to me, like Mike says, that you must be sure what model air compressor you have. There is apparently lots of room for confusion when talking about Holset compressors and air dryers. See the videos below for a brief mention of the problems that might be caused by using the incorrect dryer with a Holset compressor. If you have already seen them just ignore them.
https://www.youtube.com/watch?v=EAZJuaX1xNM
https://www.youtube.com/watch?v=LjWQStJxXf8
Bob,
I haven't followed your whole history of this problem, so you may have already seen the post linked below. If so, just ignore it.
Haldex air dryer isolation valve (https://www.foreforums.com/index.php?topic=17590.msg118355#msg118355)
Some time ago I read about the isolation valve issues and bought a new isolation valve only to find out my coach doesn't have one. It sits on my spare's shelf looking for a home. Probably put it on the classified along with other spares that were not needed.
Hi, this is so confusing but also interesting. Well this is what happens when you read part numbers off the website without actually checking to make sure that you're getting the right part. And that is all my bad.
So after dragging my stuff out of bed and taking chief for a brief walk I sprayed some parts cleaner on the side and took a picture of the air compressor. Looks like I have the whole set holset compressor which means that if I put in the wrong air dryer I'm going to have trouble with it correct? And I'm due to pick up one at Napa in a few minutes and it's going to be the wrong one. I'm guessing that I'm going to try to cancel that and put in the bypass and not worry about it until I get back to the US in April. Anybody have any other ideas on this one? Thanks.
Bob
I'm late to this discussion, but reading all the entries above leads me to this "armchair expert" opinion.
I'd like to hear Mike's (Pamela & Mike) opinion on this matter, cuz he really knows all about this subject!
1. Your air compressor is a SS296E.
2. The SS296E requires an air dryer with a built-in Econ valve and/or a isolation valve.
3. The DA33100X dryer you have ordered from NAPA is not compatible with the SS296E compressor.
4. The correct Pure Air Plus dryers with built-in Econ valves would be the DA33200X and the DA33240X.
Page (.pdf) below is copied from the Haldex reman catalog. Note I specified only dryers compatible with Holset "E" type compressors.
Pure Air Plus™ Air Dryer - Haldex product category (https://www.haldex.com/en/na/air-dryerair-line/air-dryers/haldex-newremanufactured/pure-air-plus-air-dryer/) (Under "filter by" on the left side of page, open "Notes" category, check "E" type compressors)
Bob,try and call James Trianna at Foretravel and run this by him and get his input,I would not run the bypass until April,that oil
will end up in your air system and no amount of Margaritas will help.
Bob I'm confused how a defective dryer would cause excessive pressure and installing a bypass would allow pressure to function normally? I would think a defective dryer would cause low pressure issues and moisture issues. Still think you have regulator/control issues with dryer problems added to them.
Scott
More info from Haldex about compressor/dryer recommended combinations.
https://www.haldex.com/globalassets/north-america/documents/compressors/l55384.pdf
Just looked the compressor on my '99 looks nothing like Bob's compressor 2 air lines on top and governor on the side. Don't see any tag or label from top or underneath. No isolation valve and a DA33100 dryer was on my coach when we bought it. I have put both kits in it twice now and never any problems. Evidently not all 99's are created equal.
From the stuff I was reading up above, it seems the 1999 model year was when Cummins transitioned from the Holset compressor to the Wabco compressor. Perhaps you have a Wabco.
I found the catalog linked below when I was poking around looking for info on this subject. Contains diagrams of all the types of compressors. You might be able to ID your compressor from the pictures?
http://precisionrebuilders.com/pdf_catalogs/AirCatalogPAB-0902.pdf
With the tag showing a SS296E as Chuck stated in his post #7 not only does the dryer need a econ valve it also need the isolation valve or it will cause the compressor to pump oil. With the varying supply of parts during the builds it is best to check the tag. It is not unusual to have Cman have a different compressor than Bob. The other thing is with not being the original owner the original compressor may have been changed out. You should be able to go to Cummins with your engine number and find out what compressor was on the engine when it was shipped.
Mike
Thanks Chuck,
The Wabco looks the closest. My air lines go out the top not the side. The picture doesn't have a top view.
Hey all Mark = texhub here. Bob and trusty Chief have started the journey to Mazatlan Mexico. He reinstalled bypass. Canceled the Napa order. We/I watched utube compressor and air dryer videos too late last night. There is a quick video on bench testing air dryer
https://youtu.be/ZJqLRDfnMmY.
A great d2 change out video.
https://youtu.be/FHGcXvDmZ5E
Yesterday I asked for this. Its for 2 sets of bypass fittings. Credit to a fellow forum member
Shared album - mark hubbard - Google Photos (https://photos.app.goo.gl/weg95NimdEvn9mu27)
So the plan is. Drive with bypass. Figure it out in Mexico. I believe post #7. Is right on. I have an 1999 U270. As of now. I haven't determined setup. This discussion is great as so many could be, what if are present with all coach's. When final decisions are made. It should be added to the parts list at beginning of Tech forum.
Bob does have oil sign in communication line from compressor. Unknown if line is blocked. No oil sign at air dryer. Old air can. Not cut open. It might be of interest.
Yikes, I believe my setup is the same as Bob's but none of the issues with air pressure like Bob is experiencing (my coach originally came with the N4250-DA33100 dryer - which I "just" replace with the same one...). I looked and have not observed any oily air dryer exhaust or oil from the wet tank drain... I do not know what an isolation or econ valve is or looks like. Mike, Bob, Chuck, Cman - should I order the different air dryer mentioned in Chuck's reply #7 summary? and verify with Ronnie at FOT? Below are photo's. Thanks Bob for starting the thread and for all those who have blazed this trail!
Walt,
You got one visible in the las pic. It also looks like all the required hoses are there and in place to work properly. You should be good to go. I wouldn't panic over the DA33100 as that is most likely what came on the coach. I would upgrade next time to the 33200 though as it was the upgraded model.
Mike
The Econ valve is built into some dryer models. It is an internal passage in the aluminum base.
As Mike says, you already have a Isolation Valve on your dryer, which is probably why you are not having any problem.
When you do get around to rebuilding or replacing your dryer, you should consider getting a new fresh isolation valve to go with the new dryer. Cheap insurance.
KN23500 - Isolation Valve - Haldex product (https://www.haldex.com/en/na/valves-9c82abc0/solenoid-and-isolation-air-valves/isolation-valve/kn23500/)
Thanks Chuck as I don't have the IT skills to do a point and tell pic.
Mike
Mike, to ask another way, does using the DA33100 with a isolation valve and SS296E compressor satisfy the requirement for the Check valve and Econ valve?
The attached document states: The compatible dryer must maintain pressure in the discharge line
while the compressor is unloaded or an Econ Valve and Check Valve must be used in the system.
https://www.haldex.com/globalassets/north-america/documents/compressors/l55384.pdf
Bill,
If it is working properly Yes.
By what I understand the econ valve was though up as a "belt & suspenders" kind of thing along with the isolation valve in case of failure to close for some reason. (or someone left the isolation valve off not knowing it's purpose) Yep I know of several coaches that this happened to and the control air lines were plugged.
A lot of RV techs don't understand that this is one place (air dryers) one size fits all don't work.
Mike
Thanks Mike, I have this set up currently and was a little confused by this thread.
Bill,
The OP does have major air problems we just need to figure out what is going on with his system.
There is good info here in this thread, it can just get confusing due to all the different engine, air compressors, and dryer combinations that have been used through all the years. What works on a 8.3 is different than an M-11 in the same year of engines. Throw in Detroit and Cat engines and you have a mess.
Mike
Scott, I honestly don't know how to answer that except for the fact that putting in the bypass kit and taking the air dryer out fix the pressure issues. It was no longer pegging at the top of the dial. I'm thinking that I had the isolation valve in the previous air dryer and didn't pay that much attention to the part number. I read on the forms that this is the part that they use so I didn't think anything different. I'm definitely going to put in a different air dryer. Or rebuild the bottom of the one I have now with a new purge valve and put in an isolation valve. I've got a few months to think about it since I don't really want to pay for shipping down to Mexico. But my air dryer is sitting in the front seat of my Jeep so I might be able to get them sourced in Mexico. Appreciates everybody's input on this and hopefully it won't be confusing but it will be a frame of reference on which one to use and which one not to use. The bottom line is check your air compressor on the engine. Trying to get some degreaser / brake cleaner into that area was difficult. I didn't want to get up in the ground and spray up when it would come back down on me and I already spent enough time underneath the coach taking the air dryer out and putting the bypass on. And and bit me in the auxilla area and it hurt. I did not want to get back down again so I had to spray between the air conditioner compressor in the mount for it and then put my phone kind of in sideways and take a couple pictures until I got something presentable. I'm just glad it's not the air compressor that's having problems. And I don't think it's the unloader valve because it seems to be maintaining pressure now at 110 psi.
And I replaced the governor with a new one. I guess it's possible that that governor's defective as well, but I don't think so since the pressures are holding right at 110. I used to think that the purge on the dryer was the system get rid of extra air pressure, but now no from the research that it's just to recycle and clean the dryer. Dryer. Also notice some oil on the passenger front of my Jeep being towed today. It's spotting nothing major but it wasn't there before. Also, when we got to where we're staying tonight in Mexico I open the wet tank and I got a good amount of water out along with some additional desiccant powder. I think as the water level climbed during the day it was hitting places it didn't hit before and washing the desiccant off the side of the tank.
Scott, I honestly don't know how to answer that except for the fact that putting in the bypass kit and taking the air dryer out fix the pressure issues. It was no longer pegging at the top of the dial. I'm thinking that I had the isolation valve in the previous air dryer and didn't pay that much attention to the part number. I read on the forms that this is the part that they use so I didn't think anything different. I'm definitely going to put in a different air dryer. Or rebuild the bottom of the one I have now with a new purge valve and put in an isolation valve. I've got a few months to think about it since I don't really want to pay for shipping down to Mexico. But my air dryer is sitting in the front seat of my Jeep so I might be able to get them sourced in Mexico. Appreciates everybody's input on this and hopefully it won't be confusing but it will be a frame of reference on which one to use and which one not to use. The bottom line is check your air compressor on the engine. Trying to get some degreaser / brake cleaner into that area was difficult. I didn't want to get up in the ground and spray up when it would come back down on me and I already spent enough time underneath the coach taking the air dryer out and putting the bypass on. And and bit me in the auxilla area and it hurt. I did not want to get back down again so I had to spray between the air conditioner compressor in the mount for it and then put my phone kind of in sideways and take a couple pictures until I got something presentable. I'm just glad it's not the air compressor that's having problems. And I don't think it's the unloader valve because it seems to be maintaining pressure now at 110 psi.
And I replaced the governor with a new one. I guess it's possible that that governor's defective as well, but I don't think so since the pressures are holding right at 110. I used to think that the purge on the dryer was the system get rid of extra air pressure, but now no from the research that it's just to recycle and clean the dryer. Dryer. Also notice some oil on the passenger front of my Jeep being towed today. It's spotting nothing major but it wasn't there before. Also, when we got to where we're staying tonight in Mexico I open the wet tank and I got a good amount of water out along with some additional desiccant powder. I think as the water level climbed during the day it was hitting places it didn't hit before and washing the desiccant off the side of the tank.
Keeping my Foretravel running wouldn't be possible without you guys. Thanks for your explanations, photos and support.
Bob, I plan to make the drive to Q and arrive Jan 22. Let me know if I can carry some parts to you as I am close to Foretravel and MOT (if needed).
If you do want to buy a new isolation valve I will sell the one I bought for $75.00- shipped.
Haldex KN23500 Isolation Valve, OEM# N15842J: AnythingTruck.com, Truck &... (https://www.anythingtruck.com/product/070-KN23500.html)
Bob,ask on the forum for someone with your year and engine and air compressor to see what dryer they have and go from there.
Walt's coach and Bob's have the same set up you are talking about.
Mike
Thanks but I'm in Mexico headed for Mazatlan. Won't be back stateside until April.
Bob,try cracking the drain valve open just enough to let water out but maintain air pressure,may help.
David, I did that on the drive down from South Dakota and it did keep the pressure from maxing out. Also kept the wet tank empty which was nice.
What I need to do now is fine. Either the correct air dryer which is choice number 2 or modify the existing system to work for now which is my number one choice. That would mean getting the bottom purge valve rebuilt so I need that kit as well as the isolation valve. That would be the least expensive way to modify things to work for now. But in the meantime I don't really plan on driving my coach for 5 months. So no hurry. Twig says there's plenty of trucks in Mexico with this arrangement, so that's what I'll be looking for. If worse comes to worse, I'll drive back up to the US and with the same bypass draining the wet tank as I go until I get back to the US.
Bob, keep in mind that using the drain to keep the water out will run the compressor continuously. Might be better to let it cycle as I believe from your previous posts that the unloader valve came unstuck and you were cycling at 130 psi. Then drain at each stop you make. That is if the governor is working at the time you come back.
Yeah Chuck, once I put the bypass in that's what I did. I left the tank closed and just emptied it from time to time. Which reminds me, I didn't empty it after I got the Mazatlan so there's probably water in the tank and needs to be drained. I'll do it tomorrow. If I can find a way to get mail sent down here then I might just buy that isolation valve off of you. It'd have to probably be shipped via DHL though which would incur additional shipping costs cuz it would be international.
The other thing I need is to rebuild the purge valve. I'm going to see if I can get that locally.
Had an interesting thing to happen to me and twig coming down off the mountains into Mazatlan. An 18-wheeler in front of us rear brakes caught fire and there was no place for him to pull over so he just kept going. I don't know if he even knew it. I tried to radio twig on the CB to say hey back off that trucks on fire. Twig finally saw it and went around him. We pulled over a few kilometers further down and he came in behind us no longer on fire so I guess in the end everything worked out but he wasn't driving anywhere else for a while.
If you have the Pure Air Plus you also need to check the turbo saver to see if the seat end has broken off. If you order the DQ 6020 a new turbo saver valve comes in that kit so replace it rather than thinking it is for another air dryer.
Mike