DD3s - Pricey Dinosaurs?

[Nellie Wilson]

So, a funny thing happened on the way to the forum. Well, not exactly but thought it a catchy opening.

Anyway, this guy comes by Jack's place with a DD3 can. The can has been disassembled and, wow! what a mess – rust and crud everywhere.  The parts so 'welded' together you couldn't move them by hand.

The funny (scary) thing is, the brake was working just yesterday. A new one from MCI is near a thousand bucks, and even a reman is $500.00. And this got me to thinking... if this happened to me, I would be cooked. No bus, no home, no work.

So I went straight to the MCI site to find out what I could. And, in a nutshell, these things need some major periodic attention – including an overhaul every 100,000 miles. Okay, I've got about 10 years before logging that much and I suspect that's true for most of us.

But prior owners sure logged a few, and who knows how long since our brakes have been
overhauled?  I've been pretty good at keeping them clean and lubed but, mostly, it's been superficial stuff.  I was lucky to have Ralph's help early on, as he checked my slack adjusters and installed a new can.

The aim of my post isn't to make anyone nervous or apprehensive, just to give a heads up – just 'cause our brakes are working doesn't mean they're in good shape.

For my part, I'm stuck... got to head to my next gig (a whole month, so can't miss it). But my next order of business? Tear out these brakes and do what MCI recommends!

MCI owners have another little worry too. DD3s are going (have gone?) the way of Oldsmobile and Pontiac. So seems to me, we should figure a way to corner as much DD3 stuff as we can – used, takeoffs, cores, whatever – and create a stockpile for the (our) future.

In reading some old posts, I noticed Dreamscape (Paul) had begun (or talked about beginning) something like this? Sure not trying to overreach here, but seems we share a common concern that might be minimized by preventive measures?

I'll include that MCI link, and another one (a DD3 simulator) I found interesting. Maybe that (2nd) one has some training videos or something?

http://www.mcicoach.com/fyifrommci/maintMatters/0505.pdf
http://www.braketrain.com/html/dd3.html

Sorry for the terribly long winded post, but I've never been known for brevity.

Nellie Wilson

[Van]

   .

[Dreamscape]

Nellie,

I switched out the DD-3's on our 01 Eagle to 30/30 spring brakes for about 45 bucks each and a little time redong the air lines to the cans. I couldn't see the reason to stick with DD-3's as they are expenseive as you found out. Bendix has stopped making them, but parts are available.

I had quotes from 1K to $1400 for one can, Whew, that's a bunch of dineros! If you found new for 500, that might be for a rebuild, and not many shops do that anymore. At least from what I found.

I'm only posting this for your information as I've heard switching on MCI's are a bit troublesome, not enough room. Others will post with their experience. You might be able to find some shops that still have the cans and parts on the shelf, but they are hard to find.

As many miles as most of us drive, you can replace them and not worry about it for a very long time.

Paul

[buswarrior]

Before tearing into your brakes, best to consider that if you ruin your chambers in the dis-assembly, and you disable the coach, you need $1000 for a pair of re-manufactured chambers, and the wreckage has to be good enough to turn in as a core, or you don't get 'em for $500. And you'll need 4 airlines, and if going that far, an inversion valve and two more airlines, best read up on that one too.

and you screw up your month long gig?

Maybe best to forget it right now?

No matter your outlook on the treatment of animals and coaches, sometimes you have to hit the horse to get the load pulled up the hill.

happy coaching!
buswarrior

[bevans6]

One of the big problems I have when I contemplate conversion to 30/30 spring brake cans is how to re-engineer the system.  My bus only has one dry tank, and modern (no idea when this started to be the norm, I suspect in the mid 1980's) spring brake systems have two dry tanks, interconnected but separated with check valves.  This gives you a dual braking system (front separate from rear is the norm, I think), and a degree of redundancy and emergency braking ability.  The DD3 system accomplishes this with the parking brake/emergency brake tank, which is isolated from the dry tank by a check valve and is supposed to give two or three full brake applications if the air supply fails.

When changing to spring brakes cans from DD3's, what do people do with this?  The spring brake can doesn't have the redundant emergency brake diaphragm, so I don't think you can use the emergency brake  tank from the DD3 system in the same way.  Replumbing the emergency brake tank to act as a second dry tank and creating a true dual braking system seems a bit more of a job than figuring out how to put the cans on in the first place.  I don't think having the spring brakes as the only emergency brake ability is considered proper these days, is it?

Brian

[Lin]

I replaced my DD3's when I got the bus with rebuilds from Luke at $500. each.  There are diaphragm kits to rebuild them.  I was told it is not that difficult if you know what your doing.  The internal springs are not heavily loaded like spring brakes are, so the can can be taken apart without that fear.  My assumption would be that the rebuilds should last many years in our type of use.  Just make sure the exhaust/drain is facing downward so moisture drains freely.  I suppose if you had someone that had done the conversion to spring brakes before to do yours, it would not be a bad idea since they would know the secrets in advance and not have to learn on your coach.

[TomC]

If I had that system, I'd get rid of the DD3's immediately.  They were used only in buses as a fail safe so that passengers couldn't release the brakes by just pushing in the button. 
Replace with normal truck type brake cans and you'll be alot happier.  This is one of the many reasons (besides price [my bus originally cost $4,000.00]) I bought the off brand of AMGeneral (although they did make over 6,000 buses).  AMGeneral used mostly off the shelf stuff for the buses that are available through big truck parts stores.

All that maintenance stuff that MCI put out about servicing air brakes-I've never seen a trucker do that.  If you have a good air/water separator, your air system should last just about a million miles without much servicing.  I know I never serviced the valves-just R&R when one stopped working.  But then again, I go back-trucks have universally used parts that are readily available.  Good Luck, TomC

[Tom Y]

30/30 Spring brakes WILL NOT fit on a MCI 5C without some major work. Maybe if one removed the brackets for the DD3s and welded on some new ones. The space is tight. Someone claimed to have found another brake chamber that may fit, but I could not find one. Does anyone have a good source for parts for these at a low price? I have a spare I would like to rebuild.   Good Luck   Tom Y

[Nellie Wilson]

Thanks to All -

Trying to absorb everything you say, but (for me) it's a big learning curve.

One thing for sure: Like Tom says, 30/30s will not fit my little tin can. From what I've heard, won't fit any MCI. So what's the deal with Bendix anyway? All these buses on the road and they decide to quit making brakes!? Geez. Drives me nuts. I'd swap the damn things just on principle... if only I could.

Rust issues or not, it's a pretty good argument for buying Eagles. Or maybe even GMC (bit I guess nothing is made for these anymore?).

Thanks again for any thoughts... I'm all ears!

Nellie

[luvrbus]

Go to www.mgmbrakes.com and spend a little time and you will find a spring brake that is short enough for the MCI.  
Michelangelo in Phoenix changes the dd-3 out all the time on MCI's to spring brakes without all the bs by just rotating the chamber on the brake to get clearance


good luck

[JackConrad]

Michelangelo in Phoenix changes the dd-3 out all the time on MCI's to spring brakes without all the bs by just rotating the chamber on the brake to get clearance

Clifford,
   What do you mean by "rotating " the chamber on the brake. Does he rotate the brake spider that attaches to the end of the axle?  I would be interested in changing ours to spring breakes if possible.  Jack

[bevans6]

I do believe the idea is to rotate the spider and everything to a new position.  I've spent several hours today, on that site and a dozen others, and I can't find a 30/30 spring brake chamber that is less than 8.9" tall.  I make the DD3 a tad under 7" tall (although that's a measurement off a diagram, I haven't found stated dimensions.  If there is a part number for a low profile 30/30 can, that would be cool.

I also haven't been able to find any discussion of how to modify the MCI style brake system to allow any kind of controlled emergency braking the way the DD3 does, or the dual tank spring brake system does.

I think I will just buy a pair of DD3 cans and put them in a box.  Having spares guarantees I will never need them...

Brian

[gm4106]

I got a pair of re-manufactured DD-3 from this guy. He sent them and told me he would wait up to 30 days before he charge me for the core charges. I think the core charge was more then I paid for the brake cans. I think I paid something like $375.00 for a pair. I called him a week later to see if he got the old ones to make sure I would not see more charges on my bill. But he got them and we where both happy.

http://stores.ebay.com/REI-BRAKE-SUPPLY

[Lin]

GM,

I bought a compressor from that company.  The core there too was more than the part.  They seemed fine to work with.

[Ed Hackenbruch]

Nellie, don't envy other buses......you just don't realize yet what a treasure your 5 is.