Full air brakes

Hey Swishey, got a couple of questions for you.

Your beloved KW's, what happens if you are driving one of them BOB tail and the warning buzzers and lights go off for LOW AIR ?
What do YOU DO, and WHY do you do it?
What happens to the vehicle, if you totally ignore these warnings ?

Are you totally familiar with the Westinghouse Full Air braking system ?

Just want to know your answers, to make sure of mine, that's all, nothing to do with anything else.

Anybody else who wants to cut in with an answer, then please DO IT.


regards greenie [smiley=vrolijk_1.gif]

Basically if ya don't have air the Maxi's come on and until you either get more air or wind the booster's off with the bolt you can't move. oh and when you wind the booster's off you have no park brake.

I drove from Moonie in QLD to Melbourne via Sydney once in my K104 with only about 450 KPA in the system 2 pump's of the brake pedal and it would stop luckly i had a good run and didn't have to use em much at all.

GREENIE

GuddayM8

Werk basically haz it
But U need to find the air leak n blank it off th@ way may B U only need to isolate the problem

RE:BOB tail and the warning buzzers and lights go off for LOW AIR ?

well duz depend on how fast U loosin air
coz normally if air warnings go off (buzzr,WigWag,Light) u gunna have a few secounds to fimd a place where U gunna park for a while
but haven said th@ if U push n hold in the emergency brake release It can keep the Maxis charged for a while depending on size of problem th@ air is escaping
Normally modern trucks don't dump air real quik there is normally a slight leak th@ grows over time so the drovr is aware of something th@'z gunna need fixin
When U build up max air (120psi) n cruising a drovr can tell how long B 4 the compressor govonor cuts back in
if the compressor is not makeing the 120psi U need to pullover n find problem

RE:What happens to the vehicle, if you totally ignore these warnings
I'd guess U get a full lock up with maxi's n flat spot the tyres n soil the undergarments
LOL
any following traffic will now use U as a aroundabout th@'s if U can controll the full stop

RE: re you totally familiar with the Westinghouse Full Air braking system
I'm familar with the basics but still learning
the compressor 1st feedz the wet tank this tank is the one th@ collects the oil th@ bypasses the rings in compressor
the wet tank then supplies the working tanks via a one way valve
when this tank is full then via a one way valve it supplies the emergency park brake release via a one way valve n the air start is last to cop the fill
when all is filled to 120psi the govonor cuts in n the compressor free wheels until the pressure is used up (Drops) till it is about 90psi n the govonor cuts back in to fill again

Now
Tells us all
why U need the info
n how much U got riding on the bet
LOL
Q: Did U Win?
LOL
cya

You are going to have the Maxis come on if you ignore that buzzer. The other problems you will usually find before that, is that the gearbox wont select low range even though the toggle is down and that the power clutch wont work.
BTW... have Kenworth got power clutches by now?

Yep, that's my understanding of the Westinghouse brake system as well, no air equals a quick full stop until problem rectified.
Drove trucks, trailers, flat tops and heavy haulage,as well as school buses, suburban route buses, charter coaches and express coaches, and I ALWAYS thought that no air equaled a quick full stop.

Learnt something new about 'a' certain european truck and bus manufacture that will curl your toes, it's about the braking system that THEY ALONE USE.

The vehicle in question was being used on a suburban bus route, it's got an AUTO g'box in it, while doing the daily roundy rounders, it broke a copper pipe which was attached to the "out" side of the compressor, this pipe carried the compressed air to the tanks/reservoirs, it released ALL the stored air held in the tanks to the atmosphere.
The warnings went off and the driver pulled over, applied the park brake, yep you read right, applied the park brake, remember, NO AIR AT ALL in the system.
He discovers what's making the noise and there aint a thing he can do about it. So he hops back in and without thinking, drops the park brake lever and the vehicle rolls forward, so he sticks his toe into it and it just drives, so radios in for a change-over vehicle. Then he turns the key OFF to stop the god awfull noises coming from the dash.
So he continues with the run dropping off and pick-up passengers, using just the gears to slow the bus down enough to load/unload. He was even able to use the park-brake once on a hill, yeh, you go figger it out.

He gets to where I'm waiting with the change-over vehicle and proceeds to tell me what he's done, the hair on the back of me neck starts to crawl real bad, me, I just got to take this thing fifty yards up the street and into the depot, was sweating buckets with just that fifty yard drive.

Has anybody EVER come across something like this before ?

regards greenie [smiley=vrolijk_1.gif]

I dont get that at all. I presume we are talking about a full sized bus, ie not air over hydraulic system. The only thing I can think is that the some air was getting through, despite the cracked pipe. Or there is something wrong with the way it is plumbed or adjusted, that was stopping them coming on. I think it is part of a roadworthy test that they should come on at a certain point and hold it on a steep hill.

GuddayM8
Even B 4 i finished reading your last post i also had hair on the back of me neck start n 3 stand up

Me thinks it should have a one way valve so air can only go south n not back uphill
Ifn U get my drift

with new ideas in trucks n buses U never know how n why some of these beasts ever pass a roadworthy
Plumbin n wiring of 2 day needs a lot 2 B desired
Spose the maxis coulda been plumbed up to the emergency tank from new, all works well but the guage can say sumthing else n may B from nother tank

Sounds Like U almost witnessed a catastrophe th@ we all coulda seen on the nightly news

Themz the Brakes
cya

OK, next installment.



Now this particular brand of vehicle, has it's own design for the brake plumbing, it DOES NOT work the same way that just about everybody knows or thinks that they should work, a Mr Westinghouse this beast just aint fitted with!

When this bus got back to the depot for repairs I started to ask some of the drovers about these animals, it turns out that one of 'em did the checks on one of these things before the first run, fired it up and all lights and buzzers were working, so he decided to drop the park brake and wait for the brakes to just come off with the increasing air pressure. The thing started to roll downhill straight away in the bloody yard, so he just took of with NO air for the footbrake AT ALL, by the time he got to the end of the street, he had full air pressure and was able to use the footbrake normally. He then told all the other blokes about it and they ALL did it this way from then on.

After replacing the copper tube, I took it out to a paddock for further testing, this is what I found.

Drive to test site, full air tanks, stop vehicle and pump footbrake until air gauges both read zero. Start motor and jamb it into the big "D", animal just walks away with no air at all, eh, what the F#&%'s going on here. To stop it now, I drop the park-brake, it skids to a stop. Try it again and the same thing happens again, whoa bullock, something really amiss with this thing.

So a quick phone call to a fella in the QLD transport, he said that just aint right and gives me a phone number in Canberra to ring, turns out it's the Federal Office of Road Safety, so I tell me sad story to some bloke and he passes me to another and I tell this new bloke the same sad tale. He listens and starts to ask questions and I just answer them all. Next thing he say's to me is, what time do I start in the morning and where exactly is the depot, I ask why and he say's to me, I'll see you at about 7.30 am tomorrow morning.

By the way, this is back about 1990 and these bits of junk are still being sold today.

Next morning he's there right on time, so I take him out in this thing and show him what it does. I didn't even get ten foot away from stopped, when he starts screaming, "how do you stop this bloody thing."

He then gets on the phone back to Canberra and is on it for over an hour, a fax turns up and it's a complete edition of the design rules ADR 35, which covers air brakes for ALL vehicles. It turns out that this same fella sitting in Bris, was one of the ones that drew up ADR 35 and he reckons that ADR 35 should have the wording, that a vehicle SHOULD come to a complete stop automatically, if the air pressure in all the tanks dropped below 5/8 of the normal operating pressure.

Read that, as it should work, as what Westinghouse brakes were designed to do, idiot proof or driver proof.

Here's the good bit now, when he's searching thru the ADR 35, he CAN NOT find this one sentence, that he new, should be in there. It eventuates that this one sentence was dropped from the legislation to enable this ONE particular brand of vehicle to operate, you go figger out how it was dropped and by what means were used, to make sure it was dropped.

Now I've even been threatened with a multi million dollar law suit, from the head honcho of this mob up here in Bris, it was sent to me in a legal looking letter from their solicitors, if I so much as whisper the name of this brand of european piece of crud.

They are used in just about every capitol city on route bus work and they even have quite a few coaches out on the highway, as well as lots of prime movers. So look over your shoulder when ANY route bus comes up behind, or when one is coming at you, be ready to try and avoid it, if something goes wrong with it.

Turns out the City Council bus mob, were ordered around to the depot and had the message delivered to them in no easy fashion, that they had to inform their drovers of what can happen to this particular brand of vehicle, under certain circumstances, the answer from one smart arse was, "what's all the fuss about, the things are safe aren't they?" Boy. did he get a dressing down, he was told in no uncertain terms of which way was up.

Now I wont tell you the name of these things, just that when they are younger, they are called a BOY.

If anybody ever gets a chance to check this lot out, then DO SO, be prepared for what will happen though. Better still, have a mechanic on board as well, he might even dirty his nappy, once he finds out it don't do it the way he was told it would.

regards greenie [smiley=vrolijk_1.gif]

end of rant !

Sorry M8 I aint into busses much
Dunno who Boy bus would/could B

Put it this way I could plumb up a truck/bus to do wot U just xplained
providing it is on a westinghouse type system or similar

as I previously mentioned:
the maxis coulda been plumbed up to the emergency tank from new

has there been any major accidents caused by the above system?

Cum On Greenie Spill the beans

cya

Not that I am aware of.

regards greenie [smiley=vrolijk_1.gif]