| Author |
Message |
william edgar (Honkytonk1) (216.96.18.88)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, February 05, 2004 - 2:43 pm: | |
I have a 77 MC-8 in excellent condition I am trying to sell and thought it may be a good idea to check with someone that really knows (because I don't) if I should drain the air tanks on my coach at any time? If so, how is this done? |
Nick Morris (Nick3751) (65.117.139.135)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, February 05, 2004 - 7:07 pm: | |
I was always told when I was driving my Gradall working for the county that I was to check the tanks everyday and drain them once a week. Don't know if that's too much, not enough or just right but that's what we're supposed to do with all the dump trucks the lowboy and everything with air. |
BrianMCI96A3 (69.34.169.42)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, February 05, 2004 - 8:59 pm: | |
Okay... the fact is, draining your tanks any time you are going to be stopped for a lengthy period of time, is a good thing
At the end of a day of traveling is as good a time as any.
The REASON for draining the tanks is to remove moisture and debris which over time would rust through the tanks.
EVERY air system has some moisture in it... depending on several factors, including the condition of the air dryer and the humidity, as well as the condition of the air system itself, will determine the amount of moisture and debris in the system.
Drain the tanks when they are full, as the depressurization will remove far more moisture and debris than simply opening the drain on an empty tank.
Tank drain location ultimately rests with the manufacturer and can be any conveintent place for the OEM to put it, in my MCI 96A3 it is in the right side engine bay door near the toilet holding tank.
A smart idea, something I think I'll do myself, would be installing at the drain, a 24V normally closed, solenoid operated valve, wired up to a momentary switch on the dash.
When pulling to a stop for the night you can evacuate the tank from the drivers seat!
Brian |
BrianMCI96A3 (69.34.169.42)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, February 05, 2004 - 9:03 pm: | |
Oh, and besides rusting the tanks, moisture and debris are harmful to most every component of your air system. |
Nick Morris (Nick3751) (65.117.139.135)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, February 05, 2004 - 9:06 pm: | |
Not to metion if you get a lot of moisture in the lines they will freeze up and you won't be able to move till they thaw out |
john w. roan (Chessie4905) (69.162.24.50)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, February 05, 2004 - 10:43 pm: | |
Bendix makes automatic moisture ejectors that are very reasonable in price that ejects any moisture every time the compressor cycles...mounts at drain hole on resevoir(s). Make sure you drain all the tanks. GM says to let the tank drain overnight if feasible, which lets all the oil drain out. |
FAST FRED (63.233.189.119)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 06, 2004 - 5:25 am: | |
Most "Big Truck" parts stores have pull chain drains nicly made in brass for about $7.00 each.
If you will need access to a Pit , trench ,
or to build a heavy duty set of run up blocks to install.
.
Be prepaired for a couple of quarts to gallons of oil/water/gunk from the first tank.
At least daily , and at every stop , we drain the tank , if riding in rain or very humid weather.
Works for me,
FAST FRED |
Craig S (65.202.123.254)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 06, 2004 - 7:50 am: | |
I beleive there are several tanks that should be checked. I've also found that on an MC8, they are not easy to get to at the end of the day. I like the idea of a pull chain or remote valve.
Craig S. |
Phil (204.89.170.126)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 06, 2004 - 7:52 am: | |
My Monaco motorhome has an automatic drain valve on the air tank that actuates avery time I step on the brakes> It does not have air brakes, just air suspension and an air parking brake so the demands on the air syatem are less. This may be a good source for a valve. |
Jim Stacy (32.101.44.24)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 06, 2004 - 3:36 pm: | |
Hey Guys,
I hope you're all aware there might be five or more air tanks depending on make and model. One pull cable ain't getting it.
A nice Bendix air dryer installed between air compressor or ping tank and first main tank is a tough act to beat. It dumps automatically every time the compressor turns off and flushes the filter and dessicant. Saves a lot of worrying about water (or ice) in your air system. FWIW
Jim Stacy |
NEO/Russ (66.83.53.142)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 06, 2004 - 3:57 pm: | |
FWIW, My Neoplan had seven; 5 big tanks, 2 huge tanks and one small tank. Darn if I can get anyone to tell me why. One was wet, the small was by driver for accessories. Obviously need a pair for brakes and maybe two for suspension, but that still leaves a pair unaccounted for. Chalk it off to German Engineering. And yes, it has a Bendix air dryer and drains. |
Sean Welsh (Sean) (64.81.73.194)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 06, 2004 - 8:20 pm: | |
Hey, Russ, one or maybe both of your mystery tanks was probably the emergency brake release tank. You should have a second knob below the parking brake diamond -- if you lose all your air pressure and your spring brakes come on, operating this knob will release the spring brakes long enough for you to move the coach.
-Sean |
Phil Dumpster (24.16.189.48)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 06, 2004 - 9:37 pm: | |
Bendix air dryer is the way to go - works really well up here in the maritime Pacific Northwest next to Puget Sound. Makes you wonder why they call the first tank the "wet" tank since nothing gets in there.
If your bus has an air starter, then you probably don't want to empty out the system. You'd hate yourself if you did that in the middle of nowhere and had no source of compressed air to recharge with.
If your bus had an air starter but was replaced with an electric starter, the air tanks for that (which are huge, about 50 gallons) may still be on the coach but not connected to anything.
I'm hopeful I can run across someone who has an air starter equipped 6V92 (left hand) who wants to convert over to electric, as I'd prefer to have an air starter on my bus. |
FAST FRED (65.154.177.39)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 07, 2004 - 5:37 am: | |
LUKE at US Coach will have all the parts .
Most coach owners refuse to be stranded from a slow air leak and convert to Electric Start before driving old NJ Transits home.
FAST FRED |
BrianMCI96A3 (69.34.169.42)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 07, 2004 - 1:49 pm: | |
While the introduction of the air dryer has rung out
a vast majority of the moisture in modern air systems, there are still plenty of air systems out there without air dryers.
Having attended the Bendix Heavy Duty Brake School more than once, I can also tell you that Bendix teaches that though dryers have reduced the amount of moisture in air systems there still is moisture in the system, and draining air tanks is still an important task.
Brian |
njt5150 (68.243.208.38)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, February 12, 2004 - 11:36 pm: | |
Phil I would love to swap all air system for a electric system. |
Buswarrior (Buswarrior) (64.229.210.125)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, February 19, 2004 - 9:22 pm: | |
Hello all.
Brian, that "drain" inside the right side engine door on an MCI is not an air tank drain. It only drains a small water collecting place just downstream of the compressor, sometimes referred to as a "ping" tank. It's purpose is to catch some of the moisture before it goes any further, Helps with improving the service life of the dryer. Also, you'll get most of the oil here, if the compressor is reaching the stage in its life where it is passing oil.
The tank drains are on the tanks, and have to be drained periodically.
If we want to start another religious war.... let's try to define "periodically" and the "proper methods" to drain the tanks!
For use on a day to day basis on the road, it is very handy to get the cable drains mentioned by Fast Fred and route the cables into the wheel wells, so you just reach in behind the rubber fender, pull and release, having an eye for what is actually blowing out on the ground.
A word of warning to anyone planning to retrofit an airdryer: Be sure that you have enough mileage of piping between the HOT output of the compressor and your dryer for the air to cool sufficiently so you do not cook the desicant. Cooked desicant pretty much reduces the effectiveness of the dryer.
It is very enticing to simply slap a dryer in the engine compartment somewhere.
In a bus, the air dryer is popularly found up under the front somewhere, giving lots of length of pipe to shed the heat of compression.
To give you an idea, off the top of my head, the dryer shouldn't see over 150 degrees of input air temperature, and much cooler would be better, but be sure to check this figure.
happy coaching!
buswarrior |
BrianMCI96A3 (69.34.195.205)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 20, 2004 - 3:09 pm: | |
While it is true that the air dryer should be located as far down stream from the compressor as possible, the intent as told to me by a Bendix representative, is not to keep inlet air temperature down in order to avoid cooking the dessicant, alhtough that too is something to avoid.
While it IS to allow the air to shed the heat of compression, the main purpose behind that: The cooler the air the more efficent is the air dryer in removing moisture from it.
Which is why in most trucks the dryer is usually 8 to ten feet from the compressor, which is just adequate, but in many coaches it is thirty feet away.
Brian |
BrianMCI96A3 (69.34.195.205)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 20, 2004 - 3:26 pm: | |
Oddly enough, having seen "Drain Daily" stickers on hundreds of air tanks over the years, I wrongly assumed that the "Drain Daily" sticker for the ping tank was for one of my air tanks.
I am going to look into solenoid operated drain valves, press a switch (or two or three)then roll forward and examine the asphalt for residue, how easy is that? Heck, easier still, you could do it all from the drivers seat, hit the switch(es) and (carefully) back up while looking for residue
Brian |