| Author | Message | ||
| Buddy Tennison (Buddyten)
Registered Member Username: Buddyten Post Number: 73 Registered: 7-2005 Posted From: 74.234.104.216 Rating: N/A |
Hey Guys. Been a while since I posted anything, as I am an Insurance Adjuster and have been in LA working for about 3 months. The last couple of times that we had the old Eagle out, I noticed some occurrences that I need some info on. We have quite a bit of moisture in the air system. I have manual dumper valves on my tanks, and try to remember to dump the moisture out frequently. I have noticed that my brakes have a "spongy" feel when first applied. They stop ok, but when you first apply the pedal, it feels kinda soft. Sometimes, just before coming to a complete stop, it acts like something "breaks over" and the brakes act like I've slammed on the pedal. About a year ago, had new brake shoes installed on front, and the rear ones appeared to be in good shape so we didn't change. Had all the brakes adjusted, so I don't feel like it is a problem with the shoes. When I dumped the tanks last Saturday (after several nights of pretty cold weather), it seemed like there was an extraordinary amount of moisture came out. I dumped it through 2 cycles of build-up to insure I got as much out as possible. I have also noticed that apparently my skinner valve has some moisture. When I turn the key off, it takes about 3-4 seconds before the engine shuts down. In a very cold environment ast year, it did not cut off at all, and had to kill the engine in gear. Is there some type of air system anti-freeze that I can add to keep the moisture out? If so, where do I put it in? If you have any other suggestions about my brake/air situation, please let me know. Thanks | ||
| John MC9 (John_mc9)
Registered Member Username: John_mc9 Post Number: 704 Registered: 7-2006 Posted From: 72.146.79.19  Rating: N/A |
Re: "Sometimes, just before coming to a complete stop, it acts like something "breaks over" and the brakes act like I've slammed on the pedal. When I dumped the tanks last Saturday (after several nights of pretty cold weather), it seemed like there was an extraordinary amount of moisture came out. " Back in the 60's, they dumped alcohol into the Eagles to keep the lines from freezing. There was a port on the driver's side, if I remember right. But if we (drivers) dumped the water out at the end of our trip, it usually wasn't necessary to add any alcohol. It sounds like the air dryer isn't working as it should. When was the last time you overhauled it? If it's loaded and too contaminated, the moisture won't stay in the filter, it'll just be forced into the lines and chambers. And the rollers/cams oughta' be checked for rust.. Having the brakes lock at any time, can be disastrous on slick ground. There's no way I'd continue to drive a 11 ton vehicle -like that- under any circumstance. | ||
| Paul Lawry (Dreamscape)
Registered Member Username: Dreamscape Post Number: 403 Registered: 5-2007 Posted From: 217.35.103.132  Rating: N/A |
Hey Buddy, What year of Eagle is yours? On my 68 01 I installed a Bendix AD-9 a few weeks ago. It never had an air drier, as it was an option back then. You might want to think about doing that if you have a lot of moisture in your air. Come join us at Eagles International. We have a new website and would like to have more birds on board. www.eaglesinternational.net (Message edited by dreamscape on December 08, 2008) (Message edited by dreamscape on December 08, 2008) | ||
| Jack Conrad (Jackconrad)
Registered Member Username: Jackconrad Post Number: 892 Registered: 12-2000 Posted From: 71.54.29.215 Rating: N/A |
Adding alcohol will help prevent problems with freezing, but will not prevent the moisture from forming. All air compressors create moisture as the air is compressed (high humidity=more moisture). The moisture HAS to be removed, either by an automatic air dryer or by manual drain valves (or both). Jack | ||
| Bruce Henderson (Oonrahnjay)
Registered Member Username: Oonrahnjay Post Number: 310 Registered: 8-2004 Posted From: 72.12.39.78  Rating: N/A |
Jack C wrote "Adding alcohol will help prevent problems with freezing, but will not prevent the moisture from forming. All air compressors create moisture as the air is compressed (high humidity=more moisture). The moisture HAS to be removed, either by an automatic air dryer or by manual drain valves (or both). Jack" Jack, a very experienced truck mechanic (now in his 70's and retired) told me "they make an auto drain for air tanks called a 'spit valve' - everytime it senses the surge of the compressor cutting in or out, it released a little burst of air and thus any water that's settled in the bottom of the tank". Have you ever heard of these? Do they work - in a bus air system? (PS I am planning to go to a modern, US-made, air dryer, too.) Thanks, BH NC USA | ||
| Mel La Plante (Mel_4104)
Registered Member Username: Mel_4104 Post Number: 96 Registered: 7-2006 Posted From: 154.5.119.1 Rating: N/A |
the old guy will kick in on this and will tell you that every night or when ever you shut down for the day drain your air tanks of all the moisture, this does not mean that you have to drin the air tanks completly but just enough to get the water out. now are you sure that you have drained ALL the thanks it looks like you are not draining your wet tank which is the first tank off the compressor and by your post when you say that the skinner vale is getting moisture you have a build up of water in one or more tanks. check your manual and see how many tanks you have and one of them may be a duel tank that will have 2 drain outlets. remember all tanks have a drain on them although some times guys will put a plug in them if the drain cock is leaking air and the next guy will not notice it and it can fill with water. as on other posts you can put pull chain drains on your thanks that wok well and are cheap to buy and easy to install, this is the old guys way. now the young guys with lots of money go to a repair shop and have them put on air driers or an outo dump sustem. the reason these are put on new vec. is there are a lot of drivers out there that are point and steer guys and know nothing about how it runs or stops and shuts down. | ||
| Tom Christman (Tchristman)
Registered Member Username: Tchristman Post Number: 47 Registered: 1-2006 Posted From: 66.218.33.156 Rating: N/A |
Highly recommend you install an air/water separator. They are standard in new Freightliners. I've always had one and you only have to check the tanks maybe once a month-usually no water. Good Luck, TomC | ||
| Paul Lawry (Dreamscape)
Registered Member Username: Dreamscape Post Number: 404 Registered: 5-2007 Posted From: 217.35.103.132 Rating: N/A |
Buddy, Not sure on your 80 Eagle, but I would think you have an air drier. Do you have a manual? Even my 68 has auto drains, but I still like to check them manually cause I don't trust 'em. Paul | ||
| David Dulmage (Daved)
Registered Member Username: Daved Post Number: 226 Registered: 12-2003 Posted From: 66.78.122.119  Rating: N/A |
I'd check to see that there isn't a problem with the 'S" cam & roller assemblies in your brakes. If operating properly, your brakes should work smoothly all the way to a full application. As for an air dyrer, if your coach is equipped with one, the cost of getting it serviced is not very high and it should go a long way to eliminating any moisture problem. FWIW DaveD | ||
| Mel La Plante (Mel_4104)
Registered Member Username: Mel_4104 Post Number: 97 Registered: 7-2006 Posted From: 154.5.119.1 Rating: N/A |
Buddy in your post you are talking about two thing brakes and moisture. i do not know what air brake coures you took but up here the DOT requires you to check your tanks every day of operation, this serves two good uses,it drains the water out of your wet tank and you can tell when you are getting water in the brake tank and if you have water in your aux. that is a big NO NO. also by draining the tanks after use you get to find out when your compressor is starting to go as it will both water and oil from the compressor into the wet tank. this is why you drain that wet tank so often is to be sure that any of that oil does not get into the air brake lines and if it is getting into your aux tank then that will start afecting things like air horn, wipers,air bags and other air operated items such as the shut down valve. if you have water coming out of the skinner valve you have some very ugly time ahead of you to clean out those lines, if you stast getting oil into the air lines that oil will rot the diaphram in the air pots and air suspension bags which means that you will have to replace them very soon. it is not a job you will enjoy doing as that oil will turn to gray goop and very sticky and messy, even a drop creates a mess. when was the last time you checked the brakes as to adjust ment? i check and adjust mine every 1,500 miles 2,000 max, and even if you have auto slack ajusters get under ther and check them as they do fail and will fail when you are not looking at them. so check the ajustment on them as mentioned you can have one cam causing trouble but you will see that when under there and if you are not on a pit be sure that you block it proper if you deside to slid under to look at them. just rember a 25, 000# bus will crush you real quick if an air bag goes whole you are under there. | ||
| Paul Lawry (Dreamscape)
Registered Member Username: Dreamscape Post Number: 405 Registered: 5-2007 Posted From: 217.35.103.132 Rating: N/A |
He states he has an Eagle, should not have any air bags unless a PO installed some for a leveling system. Good point about crushing anyway! | ||
| Mel La Plante (Mel_4104)
Registered Member Username: Mel_4104 Post Number: 99 Registered: 7-2006 Posted From: 154.5.119.1 Rating: N/A |
Paul the list i gave was just a general list as to what may or may not be working off the aux. tank and is not specific to any bus type nor is the list complete it was just ment to state that any anything that gets into an aux. air tank will get into those lines controling those features and the items themselves and can be very hard to clean out. while on the subject of eagles, we had a tour bus come into our area to go to Mt. Washington ski hill however they could not drive it of they BC ferrie, the air tanks were full of water, not only the wet tank and the brake tank but the aux tank. due to freezing weather the tanks froze solid and it took a heavy wrecker and a freight truck to pull it of the boat. when they got it on land we had to take a tiger tourch to the tank to melt the ice out of them.when the driver was told that he would have to take the bus to wa repair shop for check up and he did not know that there were air tanks on the bus and did not know they had to be drained dailey. he desided to not go to the shop but continue to the ski hill however he was stoped at a weigh scales and the bus impounded. the company sent in a new driver and the people arrived at the hill a day late. yes it was an eagle bus but it was not the fault of the bus just a poor driver and maintenance program. | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1425 Registered: 12-2000 Posted From: 76.68.134.176  Rating: |
This was written in response to a busnut having his bus frozen up, and he also has some custom air plumbing installed by the previous owner... He suspects that he may have also fed water into the bus via his shop air, since that's the last way he aired it up. He was reporting some success at functionality, as the day had warmed to over freezing. I am offering here an aggressive resumption to operation, now that his air system is polluted and it is winter, not routine practice. You might find something useful in this: snip Yup, hooray.... But you'll be freezing it right back up again. If you are having this kind of trouble so close to the freezing point, you have problems that will come back. Never mind the popular misconceptions, Alcohol is only a miracle liquid when you drink it...and only for a short while. Brake Alcohol is an anti-freeze, not a thawing agent, and you have to get it all the way through the lines as a vapour, when the moisture is thawed, and hope that the moisture picks up enough anti-freeze to stay wet when it gets cold again. Cold alcohol will not thaw cold ice. And the parts it has touched have already sucked any heat out of it from being inside or wherever it was stored. And the "no free lunch compromise", brake alcohol has a bad habit of weakening the lubricant in the valves, so you get them to stick later in the warm weather... Oh dear. If the valving is frozen shut by a lick of moisture on the seat, holding the rubber bits tight, you'll get no air through and of course, no alcohol through. Every check valve, every filter, every relay valve, every component that has a seat and a rubber seal, every droop in the hoses or piping... all potential sources of grief. The time for keeping an air system dry, is ALL THE TIME, 365 DAYS A YEAR, not just as the cold approaches, as you have discovered. Check the mileage of hoses and pipes in the bus, they've all got damp, wet moisture and slop in them now. How is that going to magically evaporate and become dry? This is no different than trying to dry your hands with a washroom blower that the heating element has failed...you'll be blowing a long time to get 'em dry... So it'll take a lot of running with a supply of dry air, which will require air drier maintenance and or install... Ok, scolding is over, for the moment.... The solution from the frozen north, where freezing up can cost you your life, or at least a few toes: Your goal is to keep the system dry, no alcohol needed, no valve lubrication issues, no frustrating loss of functionality in the cold weather. How to get there from here: Never mind the alcohol evaporator for now, it isn't enough to aggressively solve this problem, you need a healthy puddle of alcohol in the bottom of every tank so that the vapour may spread strongly to all components that may be affected by the moisture and be freeze prone. An outboard motor fuel line with the primer bulb, a female airline connector substituted in the outlet end, open pipe on the inlet end goes into the gallon of brake alcohol. Hold on to the fittings you cut off, someone will want them for the boat. And a couple gallons of brake alcohol. The drains on every tank get replaced with a male airline fitting and a quarter turn valve. (This also makes taking pressure readings with a tire gauge and filling with the shop air an easy routine.) Drain the tanks of air and whatever else will come out, and then pump a quarter to a half gallon of brake alcohol into each of the air tanks. You have 4 stock, one ahead of the rear axle, two behind the front axle and one up under the driver. If you find other places to store air.... well, I wouldn't be surprised, someone has been playing with it already. Start bus, go for a drive, operate all air system components repeatedly, seats fill and empty, wipers, washer, brakes, service and parking on and off a dozen times or better, front door air lock. still have the radiator shutters? Go and use the bypass valves to run the air through and through out the system. Air horn? The air suspension is the devil, hard to get flow though that without having access to the height valving. Hope for the best on this one. Leave the alcohol in the other tanks until spring, now, drain the wet tank, if you don't like the colour of what comes out, get your trusty primer bulb rig and pump in some more alcohol to help rinse it out some more. Now, drain the wet tank every time you use the bus. I will expect that your bus has no air drier or it is now useless. If you are going to use any heat, I'd contain the heat around the wet tank, transferring the warmth to the air contained there-in, and let it travel to the other places. Applying heat directly to valves with a torch is another catch 22 - that valve may have frozen seals, but the seals are made of...rubber and plastic materials...which melt or otherwise change shape if heated too much..rendering the valve inoperable or making it a leaker. You MUST be careful applying heat to valves that belong to you. That "thing" in the picture is unknown to us, and is someone's attempt to capture moisture for reasons best left unsaid to maintain whatever slim chance I still have of being heaven bound. If you have an air drier, it is in the least NFG, in that the alcohol has already been fed into it via that rig in the engine room and rendered the drying desiccant less than effective. Best not to worry about that for now, but do check to see what might be hanging up across from the two air tanks between the front wheels, on the opposite bulkhead. The air drier, if you have it, is both repairable, and replaceable. In the spring, open all drains and leave them open overnight, see what drips out. Service your air drier, rebuild all parts, including the heater element, confirm a good power source. If no drier, install one. Strong consideration to a squirt of your favorite spray lube, one that is not solvent laced into the intake end of the air valves you can get your hands on. Consider replacing the valves you do not know the age of, and then that gets accomplished at the same time. And, go and buy an air drier/water separator for your shop air, and drain that tank regularly too.... any questions? happy coaching! buswarrior | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 398 Registered: 7-2006 Posted From: 75.209.191.165 Rating: N/A |
Great looong post BW... Ian should give that one consideration for Articles of Interest (now or in the future....,or whatever it may be called)  Thanx for all (most) ) of that information! RCB | ||
| Nellie Wilson (Vivianellie)
Registered Member Username: Vivianellie Post Number: 86 Registered: 11-2008 Posted From: 70.52.106.155  Rating: N/A |
This is a really informative thread, at least to the likes of me... like 'Air Care 101' ending with an advanced seminar by BusWarrior. I now fully realize how little I know, and that is a very scary feeling. See, I imagined a bus would be just a bigger, better motorhome. But each day tells me motorhome experience is no substitute for 'bus experience' - of which I have virtually none. BusWarrior: I was thinking you were responding (specifically) to Buddy's 'Eagle' post until I got to your description of tank layout. Then I thought, Gosh, that's exactly how my MCI is laid out! Then I read closer and saw you'd first written this to another Bus Nut. Question: Was your original post about an MCI... or are all these buses laid out about the same? Re: Those tanks behind the front axle... how do I know which is which ('wet' or 'dry')? Forward of those tanks I have an Air Dryer (Bendix, as I recall). How do I service that? Is there a drop-in (or screw-on) cannister or something? Some sort of replacement element? If so, how often should it be refreshed? Seeing as I'm the ?? owner, how can I tell if the AD is still good? I didn't even know those 'behind the front axle tanks' were there until I cleaned the under carriage - one of those jobs I always INTENDED to do, but never got done. But dollars to donuts, nobody's drained them for a long time. I'm almost scared to now... afraid of what I'll see. What should I do? (Tell me I don't have to). That tank in front of the rear axle (in the rearmost driver's side bin, behind a screw fastened cover). What does it do? I didn't know it was there either, until it started leaking. I opened the cover and - guess what? - years' accumulation of road grime and mud moldering inside. I removed the tank and, luckily, found just a couple pinholes under one of the mounts. I had it welded (and pressure tested) and it seems oke now. It SEEMED to have rotted from the outside. The welding shop says the metal is still thick and not particularly pourous. So I'm keeping my fingers crossed. But what do you guys think - trust it or not? The bus has been driven so little in recent years I doubt much condensation is in the lines. At least I've seen no evidence of that. (Well, the air frames are going, one by one, but I'm getting the sense that this is a common problem?) One saving grace (hopefully): My bus has a specifically labeled dump gate - it's on the curb side, near the (original) lavaory plumbing. It has a big red and white label instructing the eoperator to dump it each day. I have faithfully done so any time the bus has run, even if just ideing for awhile. But that's the only drain I knew about. Well now I know better and just hope I haven't caused any damage. But those tanks underneath aren't so easy to get to. I guess this is where you guys have talked about pull chains and such? My gosh, I have a lot more questions but I've already taken up all of Ian's bandwidth so I'll sign off. And thanks for your patience. Nellie Wilson | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1434 Registered: 12-2000 Posted From: 76.68.135.41 Rating: N/A |
Hello Nellie. You know enough to try and know more, you are way ahead of some busnuts....! All air tanks on the coach should be drained periodically, the period depending on usage and equipment. Remember that these things were designed and intended to be run commercially, long miles every day, so maintenance practices are not geared to the casual busnut duty cycle. Some of us put less mileage on in a year than the coach would have seen in two weeks in its former life... The manufacturer has no experience in what the right thing to do for a vehicle that sits around and then gets driven a little then sits around some more. And, who in their right mind would buy an expensive and complicated machine and let it sit idle anyway? Oh, oops, never mind.... You have an air drier and the discharge muffler drain in the back that you have been draining faithfully, so you should expect to get nothing from the two dry tanks and the accessory, and maybe a little mist out of the wet tank, assuming the drier is working well. Your air drier purges when the air pressure reaches cut-out? The big sneeze? Sharp, distinct and then its done? No lingering hiss, or, no purge at all? What appears to be coming out the purge valve on the bottom? Wet, or laced in black oil, or ...? What have you been getting out of the discharge muffler? wet? light brown? oily? black? Most of the moisture is being caught by the discharge muffler and the air drier in a coach set up like yours, so you should expect to see very little or nothing in the wet tank, all things being normal. The air drier has a desiccant in it that "wears out" or becomes less effective with use. As it becomes less effective, you get more moisture in the wet tank. The air drier comes apart for servicing, everything may be rebuilt or replaced. Bendix has kits to restore or renovate, and their manuals are thorough. No worries about that project, it's a relatively easy one, and once done, you are set for many years to come , under typical busut duty cycles. For yours, I'd drain the wet tank, leave the drains open overnight and see what might gloop out, close it up, and then run a test session of many hundred miles/lots of air building cycles to see what accumulates. If you get nothing out of it initially, forget about it, your drier is fine for now, add it to the "maintenance to get around to" list. If there is a lot, I wouldn't be too alarmed initially, you have no way of knowing what was done to it before you got it. All you know is you've done nothing. Take note of the colour and consistency of what comes out. As for all this peering at what comes out: wet, great, light brown milkshake, ok, going towards dark and black, I'd expect the drier and discharge muffler to be also showing the same, the air compressor becomes a suspect, requiring further diagnosis, whether it is crap from an earlier failure or the present compressor passing oil. The wet tank is the first tank plumbed after the air drier, follow the lines from the drier. The wet tank's job is to store air, and be the first place to drop the moisture out that remains in the charge of pressurized air. The wet tank supplies air to the rest of the system, so you should see a line running between the two tanks up front. The dry tank up front is to store and supply air pressure to the front brakes. The rear dry tank is to store and supply air to the rear brakes. The accessory tank supplies the air to the suspension and the rest of the air toys that aren't brake related. Is the accessory tank under the driver's seat in your MC5C? Busnuts need to remember, the coach was discarded by a money making venture because it wasn't able to make money any more. What business in their right mind spends money maintaining an asset they are discarding? We not only have work to do, we have catch up work to do! Which is in large part, a chunk of the fun many of us have maintaining these old beasts, masochists that we are! happy coaching! buswarrior | ||
| Bruce Henderson (Oonrahnjay)
Registered Member Username: Oonrahnjay Post Number: 324 Registered: 8-2004 Posted From: 68.84.6.177 Rating: N/A |
B Warrior wrote: "We not only have work to do, we have catch up work to do!" Hey, BW, thanks for all this info. I am having a very experienced bus shop (contract with GH for over 25 years for maintenance, extensive "church bus" business, etc.) replace my system from the compressor forward. We're putting on a N American spec dryer, lines and check valves, tanks, and brake canisters. We're also taking the mechanical parking brake off and replacing it with an air park/emerg brake valve and "double canisters" on the rear axle. This is necessary because my system is a 30 year old British system - it's a "split system" front and rear but the canisters are all single, the tanks and fittings are rusting, and it doesn't really have a working parking and emergency brake system. Plus, very few spare parts are available for this system and the situation will be worse in the future - update to a N Amer system will mean that parts will be around and probably available at many places on the road and that's a much better situation. I spent my entire working career as a design and spec engineer but only for light-duty vehicles and I'll be the first to tell you that I have very little experience with heavy vehicles. All this detail info on the specifics for a heavy-duty bus system is worth more to me than just about anything else I can think of. Now, I'm working to understand the changes that this shop is making for me and also its working characteristics and how to maintain it. I really appreciate all the work that you did in composing and posting this info. It's very useful and much appreciated. |
