For MCI Experts: What was this or what should it be?

[buswarrior]

Excellent sleuthing!

I still have the combo tachograph/speedometer in my 1975 MC8 mounted on the left corner of the dash, as stock install from MCI.

Now, if someone had a box of those nasty tattle-tale cards....

happy coaching!
buswarrior

[roadrunnertex]

Give these folks a call they just might have the round charts.
http://www.atrol.com/tachograph.htm
jlv

[JohnEd]

Buswarrior,

Thanks for the post about the dryer and line length.  Very cool  

When I heard that "rule" about the lines "must be no longer than six feet" I wondered why the mfr wanted "hot" air for the dryer input.  I have never seen a bus dryer up close but if it is full of desicant, they want it cool .  I had dryers on the waveguide air compressors for my radar systems in the Air Force.  Those dryers "warmed the air" to dry it and purge the moisture.  Hot desicant doesn't hold much water...even on purpose.

Thanks again Warrior,

John

[ceieio]

Ya'll got me convinced too! 
I remember  tach-o-graphs  from the '60s.  My dad sold the units.  Drivers hated those things.
Allowed companies to analyze driver habits...speed, shift points, time spent on breaks!  They were crude by today's data collection standards. They were an intrusion on what had been a mostly supervisor free job.  They were a lot of trouble to maintain.  The little discs had to be changed too often.
JR

I knew a few drivers that would hook a bungee cord from the outside mirror to the tach-o-graph when they took a coffee break.  Loosen the mount a bit and the mirror vibrating like crazy with the truck idling would make an interesting graph.

[niles500]

Although already answered - here is the skinny - HTH

http://www.bendixvrc.com/itemDisplay.asp?documentID=4631]

http://www.bendix.com/en-us/service/library/Pages/SDSheets.aspx

TechnicalBulletinBulletin No.: PRO-08-21Effective Date: 11/1/92Page: 1 of 2Subject: Air Brake System – Cold Weather Operation TipsAs the cold weather approaches, operators and fleets alike begin to look to their vehicles with an eyetoward "winterization", and particularly what can be done to guard against air system freeze-up. Hereare some basic "Tips" for operation in the cold weather.Engine IdlingAvoid idling the engine for long periods of time! In addition to the fact that most enginemanufacturers warn that long idle times are detrimental to engine life, winter idling is a big factor incompressor discharge line freeze-up. Discharge line freeze-ups account for a significant number ofcompressor failures each year. The discharge line recommendations under "Discharge Lines" areimportant for all vehicles but are especially so when some periods of extended engine idling can notbe avoided.Discharge LinesThe discharge line should slope downward from the compressor discharge port without forming watertraps, kinks, or restrictions. Cross-overs from one side of the frame rail to the other, if required,should occur as close as possible to the compressor. Fitting extensions must be avoided.Recommended discharge line lengths and inside diameters are dependent on the vehicle applicationand are as follows.Typical P&D, School Bus and Line HaulThe maximum discharge line length is 16 feet.Length I.D. Min.Other Requirements6.0-9.5 ft.½ in.None9.5-12 ft.½ in.Last 3 feet, including fitting at the end of thedischarge line, must be insulated with ½ inch thick closedcell polyethylene pipe insulation.12-16 ft.5/8 in.Last 3 feet, including fitting at the end of thedischarge line, must be insulated with ½ inch thickclosed cell polyethylene pipe insulation.If the discharge line length must be less than 6 feet or greater than 16 feet, contact your local Bendixrepresentative.High Duty Cycle Vehicles (City Transit Coaches, Refuse Haulers, Etc.)The maximum discharge line length is 16 feet.Length I.D. min.Other Requirements10-16 ft.½ in.None
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Page 2
If the discharge line length must be less than 10 feet or greater than 16 feet, contact your localBendix representative.System LeakageCheck the air brake system for excessive air leakage using the Bendix "Dual System Air Brake Testand Check List" (BW-1279). Excessive system leakage causes the compressor to "pump" more airand also more moisture into the brake system.Reservoir Draining (System Without Air Dryer)Routine reservoir draining is the most basic step (although not completely effective) in reducing thepossibility of freeze-up. All reservoirs in a brake system can accumulate water and othercontamination and must be drained! The best practice is to drain all reservoirs daily. When drainingreservoirs; turn the ENGINE OFF and drain ALL AIR from the reservoir, better still, open the draincocks on all reservoirs and leave them open over night to assure all contamination is drained(reference Service Data Sheet SD-04-1 for Bendix Reservoirs). If automatic drain valves areinstalled, check their operation before the weather turns cold (reference Service Data Sheet SD-03-63 for Bendix DV-2 Automatic Drain Valves). It should be noted that, while the need for daily reservoirdraining is eliminated through the use of an automatic drain valve, periodic manual draining is stillrequired.Alcohol Evaporator or Injector SystemsCheck for proper operation of these systems by monitoring alcohol consumption for a few days(Reference Service Data Sheet SD-08-1 for the Bendix Alcohol Evaporator). Too little means thesystem is not receiving adequate protection and too much simply wastes alcohol. As a general guide,these systems should consume approximately 1 to 2 ounces of alcohol per hour of compressorloaded time (compressing air). City pick-up and delivery vehicles will operate with the compressorsloaded (compressing air) more while compressors on highway vehicles will be loaded less. Thesefigures are approximate and assume that air system leakage is within the limits of the Bendix "DualSystem Air Brake Test and Check List" (BW-1279). Last but not least, begin using alcohol severalweeks prior to freezing weather to ensure that the system is completely protected. Use only methanolalcohol, such as Bendix "Air Guard", in evaporators or injectors.Air DryersMake certain air brake system leakage is within the limits stated in BW-1279. Check the operationand function of the air dryer using the appropriate Service Data Sheet for the air dryer.AD-9Service Data Sheet SD-08-2412AD-4Service Data Sheet SD-08-4AD-2Service Data Sheet SD-08-2