passed airbrake exam! some questions

[bevans6]

Well, I took my air-brake course over the weekend, passed with supposedly flying colours.  The course I took was for tractor trailors, so I know a lot about tractor protection valves, glad-hands and spring brakes that I suppose I may use at some point.  I learned a lot about brake adjustment checking, compressor efficiency checks,  how the tanks interconnect and such, so that I can even figure out how the MC-5C schematic works (pretty much completely different than a truck, as it turns out).

I wonder how many people actually do the full daily inspection.  the guy I bought my coach from had owned it for 7 years, and couldn't tell me where the tanks were, or which was the wet tank.  Thank you the air dryer is working properly!

I need to get under and see if I have manual or automatic slack adjusters.  Here, it's illegal to adjust slack adjusters, manual or automatic, if you aren't licensed to do so.  How many people go ahead and adjust things themselves?

How many people actually drain the wet tank fully each day of operation?  How about the dry tank?  If you drain the accessory tank, the suspension settles down on the bump stops - is this hard on them?

Thanks for answering some newbie questions.  I want to start doing this right, and keep on doing this right.

Brian

[Len Silva]

It's a whole lot easier to check and adjust the brakes on a truck where you can practically stand up under it.

[DaveG]

1) adjust the brakes as needed-in many places you can "self certify" if you have been doing it for a while.

2)While the tank immediately after the compressor is going to get the most amount of water and therefore refered to as the "wet tank", all tanks could accumulate moisture and should be drained once in a while. To drain them, all you need to do is open the drain valve a bit for a few seconds...once the water/moisture has gone, close it back up...you do not need to exhaust all the air.

3) bump stops in air bags are for just that purpose...let 'er sit on um.

[akroyaleagle]

Brian,

The test you took was for the commercial license as applies to commercial vehicles. It is a DOT test and should be considered fundamental learning for private vehicle owners. It is mandatory for commercial drivers.

The referenced daily inspection is for drivers that drive different commercial vehicles each day.

You should do a walk around before each departure. You will develop one that fits you and your bus with experience. You should do the part of the daily that checks for air leaks in the system. If your coach doesn't pass, have the system repaired.

You do not need to get under your bus to see if you have manual slack adjusters. You may block the wheels and release the parking brake while the bus is running. Make 6 or 7 full applications of the brakes. If you have automatic adjusters the brakes will adjust themselves. If they do not, you have manual adjusters.

Manual adjustment is not difficult. It is best to have someone well versed in the procedure show you one time and you will know how to do it. It consists of blocking the wheels and if you have bags, block the bus up, release the parking brake and ratchet each adjuster down until the drum contacts the hub. Then loosen the adjuster one quarter turn. That's basically all there is to it. You do not need a license to adjust the brakes on your Private Coach.

I have auto adjusters and routinely adjust them with the brakes as described above. I also check them occasionally when I am under the bus.

I also have auto drains on the air tanks. That's the way to go. We operated tour buses for several years in Alaska. Drivers never drained the tanks. Mechanics occasionally did.
Older buses sometimes don't have dryers that work as well. Drain your tanks once in a while. If you are getting water out you have dryer problems.

I doubt if any harm occurs to the bags. Most older buses leak enough air that the suspension settles overnight.

[bevans6]

Joe, part of my inexperience is that I don't know how to tell if the auto slack adjusters actually adjusted.  How do you tell? 

Anyway, I'll probably do just what I was taught in the Army  those many years ago, and what I do to this day when I drive my truck towing a trailer - a full walk around, lights, tires, lugs, hitch and now I'll just add air compressor, leaks, emergency brake and such to the routine.  Back when i was a Gunner if I didn't drain the air tank every day I got heck, when I was a Bombardier I just did my job right, and when I was a Master Bombardier I gave heck to the Gunners!  (I was Artillery in the Canadian forces).  I have to come up with a routine (and a method) for getting under and actually checking the adjustment.  Probably every 5,000 Km is often enough, or before a trip.

I was more wondering what other people's routines were.  These buses aren't Honda's...

Thanks all

[NJT 5573]

I do a full DOT inspection every day I'm on the road, lights, rubber, wheel studs, etc. the whole thing. I also do a complete walk around inspection including the inner duals every time I stop. I do it all the time in a semi too, its just public safety as well as personal and for the safety of my family. We haul a lot of Haz Mat as well and one mistake is one to many. I don't often catch much, but there is no need to find out I have problems after they have fully developed. Its a lot easier to take care of a problem before it can get serious.

Someone burned a load of fuel in LA a couple of days ago and died. It probably was caused by someone else, but you gotta do everything you can 100% of the time to avoid the big one.

[belfert]

I'm almost positive an MC-5C did not come with automatic slack adjusters.  I suppose someone could have added them later.

I do have auto slack adjusters in my bus, but it is 15 years newer.  I still have the brakes fully inspected yearly for any issues.

[belfert]

Brian lives in a Canadian province that requires air brake certification for vehicles the size of an MC-5C.  No RV exemption there.

[Sean]

I do a full walk-around inspection to DOT standards the first time we move the bus each day.  However, I no longer check tire pressures, because we have a monitoring system for them, and I do not inspect slack adjusters (mine are automatic), simply because there is no safe way to see them on my coach.  We have the brakes and adjusters inspected every time the coach is on a lift or a pit.

For the same reason, I only drain the tanks when the bus is in the air.  I've never found even a drop of moisture downstream of the dryer, and I have an automatic drain on the wet tank.

I do know where all my tanks are, and can access them (with a great deal of difficulty) if I need to on the road.

I also do not do a bleed-down test.  When you drive the same vehicle daily, you become familiar with how long it takes to build pressure to the governor cut-out, when the governor cuts back in, etc..  I can more or less tell how cold it is outside by how long we take to build pressure from 80psi (where the on-board electric compressor keeps it when we are parked) to 120psi where the governor cuts out.

In addition to dual tank pressure gauges, I also have dual application pressure gauges, which helps to spot system trouble early on.  I also have an emergency spring-brake release tank, which I test periodically.

-Sean
http://ourodyssey.blogspot.com

[buswarrior]

Hello Brian.

Good job!

Which materials were used?  "Practical Airbrakes" or something else? The last chapter of those materials has the info on adjusting brakes. To date, I've not seen a superior product offered in the province.

You check the brake adjustment by measuring applied push rod stroke. Same as in the course. You need to take the usual safety precautions (block against collapse) for crawling under your air suspended vehicle.

What vintage is your MC5C? Single or dual air system? Some of that theory of operation in the course might throw you off if yours is single.

For brake adjustment, some periodic interval would be fine, you know where and how it has been driven. However, for air system issues, I'd be quite vigilant after any time the coach has been parked. Busnuts can be lulled into a false sence of security via our "familiarity" with some aspects of the coach, just because it was leak free, valves free, no sticking/grabbing last month.... sitting plays havoc with the inner movements and the seals.

An MC5C had auto slacks as options. My 1975 MC8 is equipped from the factory with the optional SAAB auto slacks, that look suspiciously similar to Haldex.... you never know who started what in the transportation industry... You may also find a mix, the previous owners cannot be trusted....

Yes, the regulations here in Ontario suggest that some training and a certificate from the Ministry of Training, Colleges and Universities would be appropriate for a driver to be messing with the brakes... It isn't a bad thing to take that one day course, lots of good info on the right and wrong ways, versus the grizzled stories. See if you can get your hands on the materials first, have a read and then decide.

That being said, you'll have a hard time getting into trouble for adjusting your own brakes, on your own private vehicle, in this province, unless you screwed it up, and you're liable as owner and driver of the vehicle anyway. Note, the ticket writers work for a different Ministry....

As for pre-trip inspections, you are driving an old, tired, worn out, ancient, formerly profitable, money losing, ex-commercial vehicle.  Until you have caught up all the deferred maintenance, and then keep up with the preventive maintenance,  it would serve you well to regard the coach as failing its pre-trip inspection, until it proves to you that it's rickety self can muster up enough performance to pass scrutiny.

Biggest mistake any driver (and their trainers) makes is regarding the vehicle as innocent until proven guilty. Think of it as broken until proven sound...changes how you look at the coach.

You want your coach to be invisible going down the road to the enforcement community. All lights working, all panels closed tightly, no loud noises that don't belong.... You want it to stop as well as its designers intended because you and your feet arrive first at the accident scene.

Earlier than later, a busnut really wants to have a proper wheel off inspection of the brake components. Then you know, and you can put fresh axle seals in as well. It would not be unusual to need a set of shoes and maybe drums...why would the last owner have put fresh brakes on it to sell it? You can do brakes at home, if you get someone who knows how to do all the right checks and measurements to confirm everything is sound. Buy some time from a mechanic to coach you. Parts are cheap, the labour is what kills you at a shop.

Keep the questions coming!

happy coaching!
buswarrior

[rv_safetyman]

Our Eagle has auto-slack adjusters.  When I drove it home, one of the bogey brakes seemed to "stick".  Turns out that the auto-slack adjuster for the driver bogey had failed to work properly and the "S" cams were close to going over center.  

DO NOT RELY ON YOUR AUTO-SLACK ADJUSTERS -- CHECK YOUR BRAKES AT LEAST ONCE A YEAR (OR MORE IF YOU TRAVEL OFTEN)!!!!

Jim

[Dreamscape]

Believe it or not but I check ours before every run, because we don't travel much, and it feels good to know what is going on. They are called, "Pauls Automatic Slack Adjusters". Besides I get to get dirty and hide for a while!

It just feels good to have the warm and fuzzy before we head out.

Paul

[bevans6]

My M5C is a 1980, one of the Navajo Arizona ones.  I think it has auto slack adjusters, but they are pretty greasy so I didn't get a real close look yet.  the course was a TTSAO course and used their materials.  I found them confusing when trying to relate to my bus schematic.  I don't have a primary and secondary dual system, I have a primary and parking/emergency dual system, obviously the DD3's, and the accessory tank seems to be for the suspension.  I have to study it some more to really get to grips with it.

Thanks, brian

[Len Silva]

Since our buses can be so difficult to get under for a routine brake check, I wonder about the idea of fabricating some kind of "stroke alarm", possibly using magnets and reed relays.

[kyle4501]

Since our buses can be so difficult to get under for a routine brake check, I wonder about the idea of fabricating some kind of "stroke alarm", possibly using magnets and reed relays.

As nifty as that may be, I fear that such a system would breed more contempt for the proper maintenance of a complex machine.

A side benefit of checking your slack adjusters is the visual inspection of all the associated hardware that goes with it & the surrounding area. - Air lines, linkages, suspension, etc