Braking

[Just Plain Jeff]

This is a retrieval from the dreaded thread creep under TOILETS.

Of course, both topics have the same advice: Plan A Head.

Anyway, I have driven several Prevost coaches and ridden in a bunch more. I've spoken with people who actually drive buses for a living and their general consensus is the same as mine: All buses seem to stop differently, none quickly.

Our Vague stops on a dime compared to anything I have driven. Proper inflation, load balance, disc brakes in good repair and all of that make a difference.

When you are coming up to someone in front of you and you are going too fast, the reason for slow braking doesn't matter very much...and doubtful that is what you are thinking about when the school bus' bumper is getting closer and closer.

The intention of this post is to bring up the idea and request from some for their tips about controlling the deceleration of d'bus.

For starters, here' s what I do and others may likely have better ideas:

I think of d' bus as a semi. Or worse. Kind of like a cruise liner. Keep mucho plenty of space in front of d' bus at all times...as if the guy ahead slammed on his brakes NOW, could I stop? I guess that's tip one.

For intown traffic, I have never been ashamed to punch the tranny into a lower gear for better speed control. It actually makes you feel like you are driving when you do it.

We have a real Jake brake on the Vague, unlike some of the lesser imitations, and with the S60, it is very effective; and even more effective at higher speeds. Can't prove this, but it feels like it has a stronger braking effectiveness than our previous 8V92's, likely due to increased torque of the engine. It does seem silly that an XLV would stop better than an XL, but I also suspect that front/rear balance of converted components and load make a difference as well.

There are some guys on this board who are much older than I am who may wish to provide other advice...if they can remember what it was they were going to say.

In the meantime, back to work. Someone has to pay for their Social Security benefits.

[win42]

Jeff: What's all this about my stuff is better than your stuff. On this site that kind of stuff is Verboten. And lay off the old guys, we'll tear you a new one.
So go back to counting you good stuff in private. What's a Vague?

[Jon Wehrenberg]

When I compare the two buses I have had to semis I have driven the buses do not seem to stop as fast.

The simple answer is to back off from the vehicle ahead. There is no other alternative.

From 60 mph the average car can stop in about 120 to 130 feet. We need about twice that distance or more.

[Orren Zook]

Jon,

I was reading your slack adjuster article on the other page and noticed that in one of the photos you show brake shoes/lining. What year coach are those pictures from? Do all wheels use that same style lining? If so. that could be part of the braking problem mentioned in this thread - when new a block style lining (like shown in that photo) only contacts the drum in the center part of the shoe and the lining surface won't make full contact until about half worn out. If a shoe with tapered lining is available for the Prevost application it would give full shoe/drum contact from new and should provide better braking.

[Just Plain Jeff]

win42:

I see that you have actually read the post that I made. Some of the really old guys have problems with that. They know who they are.

As to the Vague, I am not going to give the Liberty guys any more ammunition than they have already invented themselves. So, the qualities of some superior coaches have to be in stealth mode so as to not pop their bubbles. And for those who are regular Lawrence Welk fans, they are really into the bubble machine thing.

Of course the real reason I refer to our Vogue as the Vague, is that I really don't have a clue about anything other than opening up most of the compartments and driving it. That way I don't have to make up stuff about the icky stuff in the back and underneath.

Truth hurts.

[win42]

My old Pappy always taught me to never argue with an idiot. The people watching can never tell which one is the idiot. So I'll end our exchange here and let you go back to watching channel 9.

[Jon Wehrenberg]

Orren,

The brake shoes are from my 87 coach. They actually do make full contact, old or new, probably because the force on them flexes them to make that full contact.

When I relined the shoes and did my first test (my driveway is the testing ground....you need to see it to understand) the new shoes were significantly better than those prior to relining.

[JIM CHALOUPKA]

Thinking about this poor braking thing I wondered about a few things. Not having a bus to check out, just how many wheel/wheel sets have brakes? Wouldn't the braking of any Prevost conversion be a function of Prevost engineering and design and not the converter except with regard to weight.

[Jon Wehrenberg]

Jim,

You hit it on the head. A heavy bus, combined with a heavy toad without good braking or no braking is really going to ask a lot of the brakes.

The converters have nothing to do with the brakes. That is solely a Prevost responsibility.

[timebum]

Any idea why my brakes howl when I come to a stop? If I just hit them to slow a bit they are fine but if I need to use them firmly, they will howl all the way from 60 to zero.

[Orren Zook]

If you've got drum brakes on your coach, excessive wear on the anchor pins and/or anchorpin holes of your brake shoes can cause a harmonic vibration that makes a howling sound.

[matsprt]

Any idea why my brakes howl when I come to a stop? If I just hit them to slow a bit they are fine but if I need to use them firmly, they will howl all the way from 60 to zero.

Most common cause is dust.