| Author | Message | ||
| Lin Rating: N/A |
I was checking out a bus for sale this week. I had a question about the way the compressor was functioning. The gauge went up to 120# and held there fine. The only thing was that there seemed to be some air blowing off by the compressor every 10-15 seconds. I assume that it was releasing excess pressure. Should it happen like that, or should the governor cycle the compressor off when full pressure is reached and therefore not require any air release? Does that mean the governor needs cleaning/replacing? This is obviously not a major issure, but I was curious. | ||
| TWODOGS (Twodogs)
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the compressor runs 100% of the time the engine is running...the govenor moves the air to the tanks when they need air,govenor needs to be cleaned or replaced once a year...easy job | ||
| tailfeathers
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In reality it is a good sign that you are getting the pop off as it shows the air compressor is good. The governor is adjustable and you might try lowering it a bit. I assume you have an air dryer and that the release valve is good. If in reality it goes off every fifteen seconds and not every couple minutes you might replace the release pop off on the dryer. When you replace the valve make sure all air pressure to the dryer has been released. A couple dollar repair job | ||
| Brian Brown (Fishbowlbrian)
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it sounds like the unloader mechanism on the compressor and/or the governor isn't functioning properly. Although the pistons of the compressor run 100% of the time, they shouldn't be building air when the gov. tells it to cut-out. It should cut back in around 90psi, not continuing to try to compress the air and pop off that frequently. BB | ||
| Gary Stadler (Boogiethecat)
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This sounds suspicious to me. As usual, 2D has it "dead" wrong (sorry 2D, and the pun is intended... you're on my "list" now over the stupid fan thing...I continually wonder why you feel the need to pass yourself off as an authority on almost every subject on this board, when it's apparent to at least me that you're not? ) The way it works is that the compressor does spin all of the time, but the way the governor works is that as the tanks reach pressure, the governor passes air pressure into a port on the compressor that causes it to stop compressing, usually by lifting the intake valve. Then the compressor just sits there spinning but not creating any more air pressure until it's needed, and then it is enabled again. Air is never "blown off". When the governor fails, the compressor will then be compressing all of the time, at which point the next item in the line of safety takes over; an overpressure pop-off valve. If this happens, the pop off valve will open when the pressure hits it's limit setpoint, which in your case I'd guess is 120, and it will close when the pressure gets lower, say 100-110. That will cause the noise you're hearing, and at about the time-rate you're hearing it. Because there are usually 1-way valves between the compressor and the tanks (to avoid sudden 100% air loss if a hose breaks in that path) you wouldn't necessarily see any fluctuation happening on your air gauges. Another thing that can cause the noise you are hearing would be an air dryer. These things remove water from the brake air by compressing it and then reducing the pressure on it, and they cycle quite frequently on their own regardless of demand on the compressor. When they cycle, they let air off with a pop, and it could also sound just like what you describe. So if your perspective bus has a dryer installed, you may be hearing that, but it's just doing it's job normally. So Lin, I have a feeling that you're right on in every one of your assumptions. Unless the bus has a dryer, the governor probably needs replacing. Fortunately it's a common and very inexpensive part. | ||
| TWODOGS (Twodogs)
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I don't care a whole lot for you either you p888y | ||
| Sean Welsh (Sean)
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Well said, Gary. --Sean | ||
| Stan Rating: N/A |
Maybe I should ask for contributions for the fans and see how many people feel like Gary and I. | ||
| TWODOGS (Twodogs)
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,,,,,,,,,,,,,,  | ||
| Brian Brown (Fishbowlbrian)
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Stan, set up a PayPal dontate button and you might be amazed! I'll contribute to all sorts of hairbrained busnut R&D as long as I don't have to put my own bus to the test. BB | ||
| Gary Stadler (Boogiethecat)
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Stan, yes Brian has a great idea. I'd paypal you $100 towards the fan fund tonight. And if you've never used Paypal to buy your bus goodies from ebay, you'll love it. Now I gotta say, I don't mind being called a pussy at all. I've been called much worse, and heck, so what! I do wish that the guy calling me a pussy would learn to spell it though. It's spelled with a U and a couple S's. Not 8's... lets hope he can screw in a couple fans better than he can spell or they might get wrecked before the test even happens@!@ Ok, enough of the silliness. Stan, I'm serious about contributing to the fan fund.... | ||
| ChuckMC9 (Chucks)
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Mr. Brian Blue Velvet Brown, YOU'RE ON! I want to build a shower which has a pan which folds down, docking with the drain in the floor, and the walls hinged on three sides to fold out from the wall. With some gas struts thrown in there somewhere. Heck since you're an architect, you can design it and contribute your labor mostly. Now that you're not doing a conversion you have lots of time on your hands... I'll need a BOM, elev. & plan view, and a paypal donation. I await...;) | ||
| gusc Rating: N/A |
Gary, I agree with your very good and very complete description except I never heard the dryer kicking out moisture every 10-15 sec, every 5-10 min has been my experience. Therefore, I think it is his governor. | ||
| Lin
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Thanks for the info. I must add that my 10-15 second interval was just an estimate. It could have been less. It could well be the dryer, and that would be easy to isolate. The interval may have shortened as the rpm's increased. In that case, I guess it would be the governor. Anyway, if I go take another look at the bus, I will check the dryer first. I wanted to add that I have two electric fans on my bus. I have an oversized radiator that the former owner had installed. I think he took it out of a semi. Anyway, he claimed that he couldn't find a good fan for it and therefore installed the two electric fans. Later, he added a flex fan but left the electric ones on anyway. They were thermostatically controled. I changed that over to a switch up front to use for extra cooling for extreme conditions or faster cool down. They do make a difference on a long hot climb, but I do not know if they would be good enough alone. | ||
| James Maxwell (Jmaxwell)
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A bad spitter valve or a bad check ahead of the spitter is simple to detect. Rapid cycling of the spitter is indicative of a bad check valve in the dryer, which is located just ahead of the spitter valve assy. 10-15 second spitter interval is typical of a dryer problem. Governors usually either won't cycle the compression off, the most usual failure, or won't cycle it on. They seldom flat out fail from breakage, but rather become gummed from contaminated air and just don't operate properly. Cleaning is the solution. The safety pop-off is generally set well above the governor cut-out setting, usually 120 psi. Safety pop-off is generally set at 130-135. | ||
| Tom Caffrey (Pvcces)
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Gary had something wrong with his description of air compressor, governor and air dryer operation, Lin. He said "and they cycle quite frequently on their own regardless of demand on the compressor." Actually, they blow out condensate every time the governor shuts off the compressor, which will depend on how much air is being used by the bus air system. You can prove this on a system that works normally by watching the pressure gauge while the compressor is pumping up the tanks. Right when you hear the air blow from the dryer, the gauge will stop climbing. Then, you won't hear it again until the compressor finishes pumping the next time. When I start our coach after the air is down, I don't bother trying to do anything with the engine until I hear the dryer blow, except to get the generator started. It's possible to use enough air that the dryer will not work properly because it never gets cool enough between cycles; not enough condensate forms before it starts heating up again. I thought his description was a good one. Tom Caffrey PD4106-2576 Suncatcher | ||
| BrianMCI Rating: N/A |
Unfortunately Gary, while for the most part you were fairly accurate with describing the various components of an air system, you were a tad off here and there... For one, most pressure relief valves I have dealt with are set at 150 psi... Since 120 is system pressure...or should be, a 120psi relief valve would be releasing air any time the system topped off... If that truly IS what's happening, then a new relief valve is warranted. And the air dryer, it does not compress air, it has a reservoir that receives compressed air from the compressor AND it has a purge valve that receives a signal from the governor when full system pressure is released which then purges water and contaminants from the dessicant bed. The malfunction as described is in no way related to the dryer although servicing the dryer if it hasn't been done in a long time is a really good idea. This malfunction sounds to me like a defective governor and the fact is while I personally, will not waste my time cleaning a governor (they are so inexpensive) keeping one clean will give it years over it's normal service life Brian | ||
| Sean Welsh (Sean)
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Just to add another $0.02 to this discussion, I experienced this problem myself when a technician failed to properly tighten one of the small control lines between the governor and the compressor. Tightening the line fixed the problem. I never chased down the total cause-and-effect, but I believe the compressor was not getting the "off" signal from the governor, so was continuing to compress, which caused the governor to send more "off" signals which were, nevertheless, received by the dryer, causing it to purge. I don't think the safety ever popped, because the constant purging was relieving the excess pressure. FWIW. -Sean | ||
| Brian Brown (Fishbowlbrian)
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Chuck-ster: Now, as far as dontations of $ or otherwise, I did say "hairbrained busnut R&D", NOT space-saving, "thinking-outside-the-box", possibly patentable ventures. Nonetheless, I'm all over your shower idea with the mental wheels turning. I need something similar for the beach that can pop out of a bay for impromptu showering. The boating crowd may well come to your (our) rescue, at least in inspiration. Hmmm... Shall we hijack this thread further or start another? OK, since when did BNO threads ever care which direction they went! Governors = showers. Engine smoke = sexual prowess. Price of diesel = presidential candidates. Shh, I hear Sean a-knockin'... EDIT: I'm really just kidding, Sean, buddy. BB | ||
| FAST FRED Rating: N/A |
"I want to build a shower which has a pan which folds down, docking with the drain in the floor, and the walls hinged on three sides to fold out from the wall. With some gas struts thrown in there somewhere" Thats the HARD way to get dual use of space. Somewhat simpler is the shower setup I created & installed. After the shower is built in ply over a std shower pan, the entire wall of the shower that faces the center of the coach is boxed. Then a fine hanging locker and a number of drawers can be installed in the "shower. To use as a shower simply unlock the hold ins and slide box into isle. The shower is entered from the side facing the toilet area.A shower curtan is REQUIRED as it would be too much work to have the back of the hanging locker water tight in the open position seal to the frame. Harder to describe than understand , but a REAL PAIN to get the 3 sets of HD glides to line up and take the weight of the moving closet. Works for me , happily the idea was copied by a few Busnuts that visited the Sportscar in Arcadia . FAST FRED | ||
| ChuckMC9 (Chucks)
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Aaah, Fast Fred, I remember your description well and your plan has been on my priority list for more than a year, as one of the several possibilities. It's a big challenge to try to come up with an even more space-saving idea and I'm just about to give up on the wacky notion, but the overarching theme with both is to combine single-use cubic feet into serving two purposes that can only be used one at a time anyway. ...another is a tall table-top that RISES slightly less than twice its height, pulling upward the shower drape surround, which is hung from the bottom of the table-top... Sadly here on the flatlands there are no yachting boat shows from which to glean ideas. And going to RV shows is next to useless because the examples there are all alike, and shall we say, rather uninspired.  Sorry for the thread hijack folks. | ||
| Lin Rating: N/A |
I talked to a guy that had put the commode in the shower to save space. | ||
| DrDave
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Compressor governor... Another thought, If someone fooled with the setscrews in the bottom of the governor housing and adjusted the cut-in and cut-out pressures too close, It will cause rapid cycling. Been there done that. Loose screw (me!) dave... | ||
| TWODOGS (Twodogs)
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lin....two words....athletes diareha | ||
| Mike (Busone)
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You would be able to sh*t, shower, and shave all at once. | ||
| Don/TX
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Come on now, it feels like you are making fun of me. I now have a little bitty RV, potty in the shower, seems to work just fine, in fact I recommend the concept be considered in bus conversions. My theory was you spend a little time in the bedroom, little in the bath, and lots in the living area, so why not allocate the space the same way? | ||
| Jayrjay Rating: N/A |
Hey Don, I can tell you are married by your allocation of time in each area of your coach. We who are single have our priorities aligned a little differently. Since I spend a bit more time in the bedroom than you, I need the shower far more frequently, and often it is used by two or three at a time (for drop the soap lessons?) so mine is a full sized fiberglass pan from HD. I skimped by deleting the kitchen range to make up for it. Like FF says-do it chore way Cheers...JJ | ||
| James Maxwell (Jmaxwell)
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Yeah, ok, JJ, think I've heard this one before. 10 times a night and ain't worked up a sweat yet. | ||
| steve zona
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Hi everyone, I am a newbie here, and would like to say. beyond all the knowledge and info I get from this board, I also get my daily laugh from the posts. guess you gotta be a little nuts to be a bus nut. we are just starting a conversion on an mc9. are in the riverside Ca. area and would like to know if any of you are close enough to get together to chat, and maybe a reputable place to take the bus to find and repair air leaks. | ||
| Brian (Bigbusguy)
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"set up a PayPal dontate button and you might be amazed!" Id like to set up one for my tires I need. Why stop there I need a new drivers side side window too . The plastic and tape covering the big hole is just not holding up any more. But What is a paypal dontate button? Brian 4905 at some crappy camp ground in Vancouver WA. | ||
| Brian (Bigbusguy)
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oh no | ||
| TWODOGS (Twodogs)
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welp...four people didn't like buggythesillys explanation of the compressor...I say the compressor runs 100% of the time,piston goes up,crankshaft turns...govenor tells it when to compress & move air to air tanks....ya' would think somebody that stupid would keep his mouth shut | ||
| Richard Bowyer (Drivingmisslazy)
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When a compressor is RUNNING, it is compressing something. When it is TURNING it is not necessarily compressing. So the compressor is turning 100% of the time and compressing (running) only part of the time. Richard | ||
| Gary Stadler (Boogiethecat)
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For what it's worth, here's a picture of my girl, holding me, Boogiethecat. No cat poo, it's really me boogie. http://heartmagic.com/TheBoogmeister.jpg Am I smug or what ! |