We were cruising along all systems go, all of a sudden level system warning light comes on and travel light is out. Air pressure dropped to 90 in front and 70 in back. So pulled off and stopped at the first margin wide enough to get off the highway. I have a Bendix D2 governor with me. I need to find where in the engine compartment it is and how to tell if that is the problem... And I need to find out ASAP! Any trouble shooting suggestions would be welcome. I have the air schematic handy, I don't see the governor labeled on it, though I think I can tell which symbol is it from the proximity to the compressor. Going to pop the bed and see if I can spot it now.
Don
It shoukd be to the right of the engine as you face it. It has a black cover on it and under the AC compressor. You can take off the black cover and turn the screw all the way one direction then back the other way. It should free the diaphragm and lit you build air. I think you turn it counter clockwise but it has been four years since I had to do it. Then open it up again and see if you build air. It should get you off the road where you can change it out.
Hi Don,
On our 1997 U320 the governor is just behind the air conditioner compressor. Not to hard to reach from the back/outside. It may be the same location for you. Best of luck.
Raymond
If that doesn't fix it then go to air purge valve on the bottom side of air drier.
The gov will probably be the culprit... my suggestion of purge valve is next.
Something similar happened to me last year only I was parked and could not release the brake. It was the air dryer filter, it had come loose about a half a turn. Re tightened and air pressure returned. Cost me $80 for that lesson. This has happened two more times. Per the advise of an old mechanic friend put a clamp and a small spring on it to keep it tight.
With new D2 in hand look on right rear frame for the old unit if it is where mine is on my 1998. Was in plan sight on the frame rail, curb side. On my 1993 it was mounted on engine block almost impossible to see, curb side, from inside with bed up. I found it easier to replace with the D2 off the block, when trying to get the tubing nuts to make up again.
Don,
Here is where the governor is located on our 99 U270. Mark
Is that the original location of your Cummins air filter or did you relocate it there? I like that location far more than where mine is.
That is the factory location.
Mark
Update... Changed out the air Gov., no change in symptoms. Still won't build pas t 30 psi or so. The air dryer has what I think is a purge valve that is continuously dumping air while running. The exhaust port on the new Gov is also outputting air continuously but I think it normally does that until cut out. Should the bottom of the air dryer have some kind of hood or muffler? It was extremely dirty there and also has what looks like an adjustment screw. I don't think it should be dumping air like that when it isn't up to pressure... Thoughts? Does anyone have the part number of the dryer purge valve for a 99' ISC.
Don
depending on how close you are to a truck or hardware store, you can bypass the airdryer altogether with pipe fittings and a 1/4 plug. Disconnect the 2 large hoses at the bottom of the dryer and get pipe thread beveled connectors to join the 2 together. Then find the 1/4" hose that comes from the governor to the side of the dryer and screw the plug into that and you can run at 110 lbs forever. Happened to me in the middle of the desert.
Don,
Haldex Pure Air Plus is the air dryer. Service kits with part numbers are on this page:
http://epi.hbsna.com/products/dept.asp?msi=0&sid=974DA552B9D44D01BBD190038AAA6798&dept_id=2581&parent_id=0 (http://epi.hbsna.com/products/dept.asp?msi=0&sid=974DA552B9D44D01BBD190038AAA6798&dept_id=2581&parent_id=0)
Large truck parts/service place should have service kits. Some NAPAs may have them in stock as well.
Bit of a warning, IIRC that purge valve is notorious for snapping off in the dryer when you try to remove it.
Don,
I think these may help -- all of our OEM installed dryers are alike, so if yours hasn't been redesigned.......
Sounds to me as though the Governor is unloading but the purge valve is stuck or only partially shifting. The compressor can't build air with the purge valve stuck partially open.
As Twig already suggested, I would temporarily bypass the air dryer until I got somewhere that I could put in a remanufactured air dryer (easiest) or rebuild what you have with a new purge valve (more difficult).
Neal
I know you have a Haldex air dryer, but for the benefit of readers who have a Bendix air dryer, there are four little bolts on the bottom of the air dryer around the purge valve allowing you to change out the purge valve on the side of the road in a matter of minutes if you have one with you... which you probably should cuz they're inexpensive, small, and lightweight... but even if you don't have a new purge valve with you take out the old one, clean it, and put it back in to see if that fixes it.
Okay, useful suggestions abound! Thanks one and all! I may have the parts to bypass the dryer with me, but there are several hoses connected to the dryer and a 1/4" plastic air line, which I believe is the one that Twig said needs to be plugged. That I have done. The outlet hose on the bottom of the dryer assy appears to have 3/4" female pipe thread (I haven't removed it yet) and there is one othe slightly smaller outside diameter hose that is connected up on the side. Are these the two hoses that need to be joined to bypass the dryer? I happen to have a short 3/4" pipe nipple with me if that is the correct size. I also have a 1/2" nipple as well, but pretty sure it isn't that. If this works out, I will by a rebuilt unit in Calgary and take the old one to rebuild back home.
Don
I have tried to attach a picture off the fitting I used.
Don,
On mine I disconnected the two big lines at the bottom of the dryer then connected them with the above fitting.
Big line from the compressor and big line from the dryer to the wet tank .
I disconnected the 1/4 inch line that went it the wet tank.
All info I got from Twig while sitting on the side of the road.
Don, I know there have been many suggestions here but my 2 cents is that if you can get a service kit for it close to were you are just take it off and rebuild or just do the purge. It really is easy to do even in place. You have masterd many tough issues so this one to you is a 1 out of 10. I have done this rebuild now 5 times (total service) and wish all things are that easy.
JohnH
Ty's went in the toad to try and find a fitting. Nearest town is 13 miles from here and not very large. I guess the in and out hoses are the ones with the ¾" threads are the two to join. Still not sure about the ¼" line to plug. The one that goes to the governor is braided and uses a similar tapered fitting as the large hoses only smaller. The one I have a plug fore is a ¼" plastic line like the step air cylinder uses, a compression ring fitting. We only have slow internet on our phones at the moment. I will try to attach a picture of the bottom of the dryer with the two large hoses removed. Can anyone confirm that the two hoses that attach to the areas where a hose has obliviously been removed are the correct ones to join and that the plastic line (still in place here) is the one two plug?
Thanks, Don
Edit: naturally, posting picture from my phone ends up upside down ???
Don't worry about it - we can see what you're asking about (wish I had the answer, but I'm sure someone will chime in soon).
Where are you guys currently located? Maybe a Fofum familiar with the area can offer parts vendor suggestions?
Bless you Michelle! We are 49 miles south of Calgary in Alberta, Canada on north bound HWY 2 (just north of a town called Nanton).
Don
Don, been looking on google earth and there are a few diesel shops around High River but most of course in SE Calgary. Nanton seems pretty big enough for a shop. Find the local cop shop RCMP and ask them to locate one for you.
JohnH
Don,
I've used Calgary Diesel Services in the past; they are in south Calgary and good to work with. Their number is (403) 262-5750 (ask for Peter or Rod). If they have what you need (they may also have a new/replacement dryer on hand), I could pick it up for you and bring it out first thing in the morning.
Grant
Don,
Attached find some notes on your photograph. My Control Port from the governor is nearly opposite the inlet port. There is a label "Control" cast right into the dryer bottom casting. Yours looks a bit different. But there is only one line, with 1/8" NPT end fittings, that goes directly from the governor to the dryer. That's the one you need to plug -- at either end.
After bypassing the dryer, on engine start, watch your gauges carefully to make sure that the compressor is still being controlled by the governor. Be ready to shut down if pressure isn't being properly controlled.
Good luck and best wishes.
Neal
Don, what Neal said is correct, except the inlet fitting is a JIC fitting. The threads are not tapered like NPT are. Good luck and hope you get on the road soon
Richard B
Thanks all... Too tired to say much except we made to Calgary. I managed to scab together a bypass fitting out of the two elbows (separating them from their fittings was tough) that the dryer in and out hose were connected to couple with a ½" female pipe threaded gate check valve that I had on hand. Pressure built up to 123 PSI but not beyond and stayed up above 110 PSI all the way to Northwest Calgary in a church lot across from Calaway Park where we will be staying the next few days.
Now to get some sleep...zzzzzz
Check your treadle valve,under steering wheel,hard to find,mine blew took along time to diagnose. John
Right you are, Richard. Thanks.
The air system inlet and outlet hose end fittings are JIC. In my midnight rush to get some thoughts back to Don, I landed the arrow on the JIC end of what appears to be a JIC to 1/2" NPT elbow. The Haldex dryer inlet and outlet ports are 1/2" NPT.
So, it might serve us well if we all carried:
- 1/2 X 1/2 NPT female coupling (would have to use the 1/2" NPT fittings off the dryer (or like), in order to connect the inlet and outlet hose ends)
- 1/2 X 1/2 JIC male coupling as John Duld suggested (directly couple air system inlet and outlet hose ends)
Neal
This essentially what I made by the side of the road last night... But doing it out of the original elbow fittings required more disassembly than I would have liked, especially since I couldn't raise the coach to put in the frame blocks. Had I this part, yesterday's stay would have been at least 6hrs shorter and had I this part and known what the problem was, I could have done in about 20 minutes!
Just for information in the future, if you can't locate the line coming from the governor to cap off you can open the water bleed valve on wet tank to balance air pressure until you get to a better location. In other words the pressure will build and build but once the bleed valve is opened a smidgeon, the air pressure will balance.....too high pressure....open a smidge more....you get the idea.
I've been following this blog, and very happy that Don was able to effect a solution to get off the road. I intend to make up an emergency bypass kit.
Neal's post indicates a 1/2" x 1/2" JIC coupling.
Barry and Cindy's post indicates a 3/4" x 3/4' JIC
Are these the same fittings?
Thanks for the help, Dave A
I am not sure of how the fittings are described properly, but one end of the elbow is ½" male pipe thread and the other (JIC) end is roughly the same diameter as a ¾" male pipe thread without the taper and with a 37 degree bevel on the end. These seal metal to metal on the bevel and the pipe thread end needs a sealant. Using the original elbows for the bypass will cost you a lot of time! I am trying to locate a rebuilt unit now but they are not apparently commonly stocked in Calgary. Using just a straight JIC male coupling to join the hoses is possible as Twig says, but on our coach, using two elbows with a female pipe thread coupler makes it much easier to minimize hose rerouting. I will have more to say about that when I catch up on some z's.
Don
Not at my computer, but I think the following is correct:
Size 1/2"
DESIGNATOR JIC-08
THREADS 3/4-16
MALE THREADS OD 3/4" (.75)
FEMALE THREADS ID 11/16" (.69)
Neal
Don,
You may feel a tiny bit better about your recent misadventure, if you realize that others have benefitted from your experience. I have been telling myself for some time that I needed to go through my air system. My air dryer was last changed (by PO) in either 2011 or 2012, at 148,000 miles. I now have 164,000 miles, and it's either 2 or 3 years, so I figure it is due. I don't mind doing this maintenance stuff a little early, in the comfort of my driveway, rather than on the side of the road in the middle of the night.
I made a run to town today, found a remanufactured Bendix AD9 in stock at NAPA, bought it for $169.00 + tax and core charge. I think my coach presently has the AD4 so this may be a "upgrade" when installed. I also picked up a new D-2 governor at NAPA. Although my (original?) D-2 is still working fine, I will feel better having a fresh one in place.
I will keep the old one for a emergency spare.
I also stopped at a hydraulic store (lots of those around here in the heart of the oilfield) and bought the parts to make the emergency dryer bypass. I actually got sufficient parts to make 2 of them - if I ever come across another Foretravel stalled on the highway with air dryer woes, I'll have a extra one to loan him! The part numbers and description are shown below. Total for all 6 pieces was $30, so it only costs about $15 to buy yourself a great deal of "peace of mind". Cheap insurance! ^.^d
Part #2501-12-08 3/4 M-JIC / 1/2 M-NPT / 90 DEG $5.30EA
Part #5000-08-08 1/2 F-NPT / 1/2 F-NPT / COLLAR $2.96EA
Thanks Don, Neal and cajk, Off to find a hydraulic shop or may even try a big box store.
Love this forum...dave a
Chuck, wow, you went first class and bought stainless steel fittings!!
Yes, everything in the oilfield is
high-dollar (but, the fittings are "Made in China".... as is the D-2 governor).
What looks to be a cross-reference for the elbows
Stainless Hose Fittings LTD. | STAINLESS STEEL 90° ELBOW ADAPTERS (2501-12-08) - (http://www.stainlesshosefittings.com/index.php?id=2315)
It is easier to get the coupler that Neal shows in his write up, that way you only have to take the two large hoses off at the dryer and hook together and plug the small line to wet tank.
Crazy J
2002 Foretravel U320
2009 HHR
I have not actually used this bypass device yet. I will have the opportunity to try it during the process of removing my old dryer for replacement. I will decide then what arrangement would work best on my coach. Don (see quote above) seems to think the "2 elbows + collar" setup is preferable for his coach. Different strokes for different folks!
I haven't had any luck finding A rebuild airdryer (part # DA33100x) in Calgary, or even in Edmonton in stock some place... even with the help of a Calgary foreforum native (thanks Grant!), though Grant found someone in Edmonton who claims to be able to rebuild your own (for about $270 I think) and turn it around in one day. I may go that route if I can't find the kits in stock someplace. My Internet access is fairly limited (only via my phone) unless we go hang out at Starbucks or some such. From what I have looked at, the part numbers are DQ6020 (Major repair kit), and the DQ6026 (Genral Repair Kit). Can anybody who has done the rebuild verify these part numbers or tell me what the proper numbers are to do a complete rebuild?
Thanks, Don
It looks like there is more than one type of dryer plumbing installation so you will need to inspect yours so you can get the fittings needed to bypass your dryer.
Also be sure you carry the wrenches to get those lines disconnected.
Mine were very tight and access was limited.
Don they are the right #s and really it is an easy service, but better if you take it off after screwing the dessicant filter off first as you really need to get a good hold of it to break seal.
Drive with it like it is now and see if you can make here as part of the round trip. We are only 10 hrs from Edmonton but have family here till Tuseday and no room for parking etc but after that no problem.
The Air dryer is same as mine and those parts cost me total of around $168 for all from Ryder Fleet parts in US. Total time to service is around 2 hrs in and out. They are available here but cost 2x that
JohnH
Don , I did mine recently. It looks like you have the right numbers. Mine had the same symptom as yours but I was able to build pressure. It just purged almost constantly. It turned out to be a broken turbo saver valve. It comes with a new one in the kit. It is really an easy process to rebuild it. Here is a picture of the broken plastic valve.
Mark
Don, here is a photo, with notes, I took in early 2011 at FOT. BTW, they removed that large air line shown to make access to the pop-off easier.
Dick
Here is a follow up on our recent roadside "adventure". We made it to Calgary just fine. The Air built up to about 123PSI and didn't go past that. We stayed in Calgary for a couple of days at Calaway Park campground, which has nothing much to recommend it unless you like paying an exorbitant amount for a crowded poorly designed campground with $10 a day WIFI (we passed on that :o ). The good of it was a nice dinner and meet up with Grant and Betty who are two of the nicest people you could hope to meet. Grant (of the forum) hooked me up with the fittings for EDB (to reference Chuck's thread) so if this happens again, I won't have to spend more than 30 minutes or so by the side of the road.
Back to the subject at hand... We left Calgary heading north towards Dinosaur Trails campground, but not without incident. About halfway there, I noticed that the air had built up over 130PSI and was still climbing. As soon as I noticed, I used the brakes to keep dumping air until I could get to a spot wide enough to get out of the flow of traffic (which thankfully, there wasn't much of). There I cracked the tank drain valves and started back up again. The rear tank had quite a bit of water come out and one of the fronts just a bit. Anyway, once we started out again the air keep building in spite of the valves being cracked open. I stopped two more times making an adjustment each time until we could proceed without exceeding 135PSI or thereabouts. I figured that since I didn't plug the connection between the Dryer and the governor, the cut out wasn't kicking in... though I don't yet have a clue what changed between the first leg of the trip with the bypass and the second unless there was just so much more moisture in the air on the second leg.
Anyway, I pulled the governor back off to take a look and I noticed part of the old gasket was still stuck on (not sure how I missed it by the side of the road, but conditions weren't good...) where the governor bolts to the compressor. Maybe that had something to do with it? I used a male pipe thread plug to seal the control port on the governor because I couldn't find any flare caps of that size to plug the hose end and made sure mounting area where the gasket goes was clean. Since that port between the mounting bolts is one of the three "Unloader" ports and matches up with a port on the compressor, I am guessing that the one that goes to the dryer is splitting the air with the one attached to the compressor which should explain why the the bypass works without over building pressure, unless the one going to the dryer is spilling out into the open are through a passage in the dryer and then the compressor unloader doesn't have enough air pressure to signal the compressor stop compressing.
Of course, the air systems in our coach is an area which I have a long way to go before I feel that I have a good handle on it, so I could be completely wrong and would appreciate if if any of more experienced forum members could set me straight.
I finished phase 2 of my bypass, but I have to wait until the campers in the space directly behind me leave in the morning before I can test it... unless a nice wind comes up from the right direction! The reason I am still messing with the bypass is that I couldn't find the parts to either exchange the whole dryer unit or even locate a locally available source for the rebuild kits in Calgary. I don't like driving the coach like this, but I don't seem to have a choice just now. Mastering the air systems of our coach and maintenance thereof has bumped way up my list of must do activities!
Don
Don, like I said earlier in this posting "get your a-- over here and let us rebuild the Dryer etc over the pit" as I do not like hearing about Forum members stuck on the road when there is room and facilities for fixing properly your problems. Maybe you do not want to come this way and do not like fresh fruit and veggies???
JohnH
That's a very generous offer, John, and I know Don would love to have a pit to work in rather than crawling under the coach! However, we have promised my kids in Edmonton this visit and they, not to mention myself, would be very disappointed to skip it when we are so close. Also, we would be even more nervous getting the coach over the mountains and all the way to your place than we are about getting it to Edmonton in its present "bypass" condition.
We are both looking forward to visiting you and seeing your setup mid September if your are home then...sure hope there's still some fresh fruits and veggies left!
Tys and Don
well from Edmonton thru to Rocky Mtn House is flat then it is a short distance thru the rockies to eastern BC AND it is on your way home to S Diego via 97 and I 5. depending on a few Dr visits we should be in Utah in mid Sept. It really is not that far here, but whatever you want to do is fine of course.
JohnH