Bus Conversions dot Com Bulletin Board
September 01, 2014, 09:47:17 PM *
Welcome, Guest. Please login or register.

Login with username, password and session length
News: If your computer is lost, damaged, or stolen, we will replace all of your E-Mags for free.
   Home   Help Forum Rules Search Calendar Login Register BCM Home Page Contact BCM  
Pages: 1 2 3 [All]   Go Down
  Print  
Author Topic: Question for DD-3 to Spring Brakes on an Eagle 01  (Read 3406 times)
Dreamscape
Guest

« on: October 09, 2008, 07:40:36 AM »

I have a leak on one of my DD-3's. After investigating, downloading and studying, I have a question as I am muddling my way through this. I have no hands on experience with this, but I want and need to learn the best method of diagnosis and reapair.

I got out a trusty spray bottle with soapy water and squirted every hose, fitting and relay I could find. No leaks when service brakes are not applied. You know how much fun that is when you don't have a pit!

When the service brake is applied I have an air leak on the RH facing the front. The leak is coming from the area of the splash guard. (By the way the boot is shot). I am assuming the service diaphragm is shot, as there is no leak when parking brake is applied.

I always hate to assume anything, am I on the right track? If not would you please redirect me. Wink

Thanks in advance for the help,

Paul
« Last Edit: October 10, 2008, 03:53:27 AM by Dreamscape » Logged
Sojourner
Jesus Love You!
Hero Member
*****
Offline Offline

Posts: 894


WWW

Ignore
« Reply #1 on: October 09, 2008, 10:19:37 AM »

Bad diaphragm...remove the largest clamp to R&R diaphragm. You need to take old part to any heavy duty truck parts or NAPA or Car Quest will have them in stock or order over night. The coil spring is easy to compress...not the danger type like in spring brake can.
The reason to take your old part in is that some have larger diaphragm instead of OEM size. Mine did.....size 36 instead of 30.
Boot is to protect rocks & sand as well water during icing weather from getting in.

Before reinstall the new diaphragm...wire brush around the clamp's rim to remove dirt and wipe clean. You may have some rust on rim but if it not too thin... it should be OK. If you are not sure of the condition...take a photo of the rim & post it.

http://www.bendixvrc.com/itemDisplay.asp?documentID=2393

DD3 Bendix Parts Break Down:
http://www.bendixvrc.com/itemDisplay.asp?documentID=2704

MCI parts DD-3
http://www.mcicoach.com/Parts-Service-Support/coachGuard/brakeChambers.htm


MCI Service DD-3
http://www.mcicoach.com/Parts-Service-Support/serinfo/serinfo04E.htm

State Inspection information:
http://leg1.state.VA.us/cgi-bin/legp504.exe?000+reg+19VAC30-70-440

FWIW

Sojourn for Christ, Gerald
« Last Edit: October 09, 2008, 10:48:30 AM by Sojourner » Logged

http://dalesdesigns.net/names.htm
Ps 28 Blessed be the LORD, because he hath heard the voice of my supplications. The LORD is my strength and my shield; my heart trusted in him, and I am helped: therefore my heart greatly rejoiceth; and with my song will I praise him
Dreamscape
Guest

« Reply #2 on: October 09, 2008, 11:24:10 AM »

Jerry,

Thank You for the information.  Smiley

I priced new ones and WOW! I think I will try another way.

If I buy one diaphragm I'll buy two. Won't hurt to have a spare or one for the other side when it fails.

I am still doing research for parts and availability.

Paul

Logged
Sojourner
Jesus Love You!
Hero Member
*****
Offline Offline

Posts: 894


WWW

Ignore
« Reply #3 on: October 09, 2008, 11:34:53 AM »

I believe yours is size 30 diaphragm. I don't remember that DD3 #30 diaphragm is deeper draw design than standard can but if you take old one to compare. If anything they order one at NAPA or Car Quest auto parts store.

The main thing is to clean the locking balls & piston with oil until it flushed. If your not sure the DIY servicing, look for old bus mechanic pro to have it service.
« Last Edit: October 09, 2008, 11:40:43 AM by Sojourner » Logged

http://dalesdesigns.net/names.htm
Ps 28 Blessed be the LORD, because he hath heard the voice of my supplications. The LORD is my strength and my shield; my heart trusted in him, and I am helped: therefore my heart greatly rejoiceth; and with my song will I praise him
Dreamscape
Guest

« Reply #4 on: October 09, 2008, 12:00:38 PM »

Yes Jerry it is a size 30.

I'm not afraid of doing the work. I will follow your advice on cleaning and oiling.

Actually I am enjoying doing the research as I am learning something new and I am not afraid of doing the work. Besides my labor is pretty cheap!

I will take my time with this project to ensure it is done correctly.

Paul
« Last Edit: October 09, 2008, 12:03:01 PM by Dreamscape » Logged
FloridaCliff
Hero Member
*****
Offline Offline

Posts: 2458


"The Mighty GMC"




Ignore
« Reply #5 on: October 09, 2008, 12:06:58 PM »

Paul,

Call me later.

I will IM my number.

I have repaired and replaced several times.

Cliff
Logged

1975 GMC  P8M4905A-1160    North Central Florida

"There are basically two types of people. People who accomplish things, and people who claim to have accomplished things. The first group is less crowded."
Mark Twain
Dreamscape
Guest

« Reply #6 on: October 09, 2008, 12:16:01 PM »

Got it! When is the best time to call?

Logged
luvrbus
Guest

« Reply #7 on: October 09, 2008, 01:12:42 PM »

Paul, change it over to spring brakes your not working on a GM or MCI there is plenty of room for spring brakes on a Eagle
Logged
Dreamscape
Guest

« Reply #8 on: October 09, 2008, 03:15:27 PM »

Clifford,

If I had the money I would, but right now I just need to fix what I have with what I've got.

If I can make plans to go to Quartzsite I will need the extra cash for fuel, I'm trying to think ahead.  Grin

Paul
Logged
luvrbus
Guest

« Reply #9 on: October 09, 2008, 03:22:10 PM »

Paul, I'll check Friday if I have a set I will ship them to you good luck
Logged
JackConrad
Orange Blossom Special II
Global Moderator
Hero Member
*****
Offline Offline

Posts: 4447


73' MC-8 8V71/HT740 Southwest Florida


WWW
« Reply #10 on: October 09, 2008, 04:35:02 PM »

Check with Mohawk Industries.  Much cheaper than MCI.  That service diaphragm is specific to the DD-3. It does not interchange with other brake diaphragms.  Jack
Logged

Growing Older Is Mandatory, Growing Up Is Optional
Arcadia, Florida, When we are home
http://s682.photobucket.com/albums/vv186/OBS-JC/
buswarrior
Hero Member
*****
Offline Offline

Posts: 3571


'75 MC8 8V71 HT740




Ignore
« Reply #11 on: October 09, 2008, 05:03:10 PM »

Hello Dreamscape.

Hold on a minute, on two fronts.

First: on the DD3

Did you do the soap spray with the parking brake released and the service brake released?

Just to rule out that it isn't the locking port circuit bleeding through.

Since the boot is torn, and you are taking it apart anyway, I'd recommend doing the parking diaphragm too, and then it is all done.

Second: on a spring brake conversion

a spring brake conversion... you might want to think about doing it now.

Spring chambers are, give or take, $75 each, less than diaphragms for the DD3.

Side question: Will long stroke chambers fit in the space in an Eagle?

Off the top of my head, no schematics or studying has been done, in a belt and suspenders world, certainly not according to Hoyle and all those other rules... All bets are off and don't be sicking a lawyer on me....

You might be able to swap the chambers and just plumb it all up with what you have.

The line to the locking port on the DD3 connected to the spring portion, (pressurized when underway in both applications) and the service line connected to the service line, (no confusion here) and the parking line terminated (pressurized when parking, not applicable to a spring brake system, not needed) this would function.... wouldn't it?

You may have to pause for a moment on release for the spring chambers to fill, as the air would have to travel via the skinny, long and winding road instead of via a relay valve and shorter, bigger passageways....

But it gets you headed in the right direction without spending money on chambers you want to eventually get rid of.

To the congregation, before we go running off like free spirits and start converting, what is it that I'm forgetting? Is this a blasphemy or an inspiration?

PS, I get first dibs on Paul's old DD3 chambers, if this works!

happy coaching!
buswarrior
Logged

Frozen North, Greater Toronto Area
Dreamscape
Guest

« Reply #12 on: October 09, 2008, 08:27:52 PM »

Buswarrior,

After reading your post and what Clifford has emailed me I am giving it some serious thought.

I really would like to know if anyone has done this on their Eagle.

I am not one to re invent the wheel, but if the wheel is ancient and the new one will work better and costs less, then I'm game.

Has anyone done this on there Eagle?

By the way I did not check it with no parking brake and no service brake. I can see your point though.

I do have a lot of room for the conversion to spring brakes.

Why in the heck would you want two tired ole DD-3's anyway? LOL

I'm a waitin'

Paul
« Last Edit: October 10, 2008, 02:37:49 AM by Dreamscape » Logged
Sojourner
Jesus Love You!
Hero Member
*****
Offline Offline

Posts: 894


WWW

Ignore
« Reply #13 on: October 09, 2008, 08:46:46 PM »

Dreamscape....buswarrior is right....I forgot that there also air applied to roto-piston as well about 70psi. It could be still leaking if you release service brake. I think the way you posted, it leak only when service brake is on which mean the diaphragm is leaking.

By all mean as per buswarrior to replace ages old rubber parts. Check air hose for cracks skin.

Now I am half a-sleep...too tired to think clearly...running out caffeine in my so call brain.

FFFwwIIW

Sojourn for Christ, Gerald
Logged

http://dalesdesigns.net/names.htm
Ps 28 Blessed be the LORD, because he hath heard the voice of my supplications. The LORD is my strength and my shield; my heart trusted in him, and I am helped: therefore my heart greatly rejoiceth; and with my song will I praise him
Dreamscape
Guest

« Reply #14 on: October 10, 2008, 04:02:30 AM »

OK Guys,

I changed the original title because I think that changing to spring brakes makes a lot of sense, not only updating but the pocket book also.

Clifford and Buswarrior brought up some good points. I was really unaware that this could be done as I am not acquainted with it.

What is needed to change it over? Is there anything like changing any valving etc.? With the DD-3 having three hoses and spring brakes having only two, what is done here? Is there any information on the web that describes the procedure?

Your thoughts please,

Paul
Logged
luvrbus
Guest

« Reply #15 on: October 10, 2008, 07:12:51 AM »

Paul, contact Ed or Norris at Jefferson they had the instructions at one time I have it but have been unable to locate it for you and I don't have any spring brakes left it is a fairly easy change over on your bus no brackets to be fab just get the right stroke but I forget what you do with extra hose,now is when I miss Roy at Jefferson he could have told you on the phone he knew his GM and Eagles like no one else but God had others plans     good luck
« Last Edit: October 10, 2008, 07:28:44 AM by luvrbus » Logged
Sojourner
Jesus Love You!
Hero Member
*****
Offline Offline

Posts: 894


WWW

Ignore
« Reply #16 on: October 10, 2008, 09:15:21 AM »

Great posting...Dreamscape on this subject!
Thanks you all!

Jefferson Truck, Trailer & Bus Parts:
http://www.busesonline.com/findparts.htm

I just talk to ED about spring brake conversion to my MCI-8, (I didn't ask about Eagle...it already posted) he said it allot of work but any 30-30 spring brake can will work. I appreciated his information, very nice of them.

I do know this must about hose connection...one hose "locking" is to be removed. Service hose to service port. Emerg hose need to in reverse air signal....instead of apply air psi to park mode...it need to release air psi for park mode. Ed didn't tell me how it need to be change but said "allot of work".

In the mean time, I am going to study the air diagram of both version and make a conversion diagram for MCI for now as soon as possible. And later still a plan for mounting them into MCI-8, 9.

The Eagle and GM...if anyone already has one, could you please share us yours? My email is silverclip1 at AOL dot com    Thank you.

FWIW

Sojourn for Christ, Gerald
Logged

http://dalesdesigns.net/names.htm
Ps 28 Blessed be the LORD, because he hath heard the voice of my supplications. The LORD is my strength and my shield; my heart trusted in him, and I am helped: therefore my heart greatly rejoiceth; and with my song will I praise him
Dreamscape
Guest

« Reply #17 on: October 10, 2008, 09:36:19 AM »

I spoke with Norris at Jefferson Bus and this is what he told me.

First, he does have the diaphragm kits for the DD-3, about 95 bucks each.

Second, he is out of stock, but normally has the rebuilt DD-3 with exchange, about 300 bucks each.

He was not able to find the drawings for the conversion from DD-3 to Spring Brake, he thinks they were thrown away.

Norris gave me the name of a guy who has an Eagle that the brake conversion was done on, not by him, but another mechanic. He said that he had all kinds of problems when a spring broke and would not recommend changing them out from DD-3's.

So I called Pete, he lives in Colorado, and got his side of the story. He says he has 50 years of experience with highway coaches, and would not recommend spring brakes on any of them. When a spring brake fails for one reason or another, you have to go under the bus to manually make an adjustment to move it. This happend to him on I-25, an 18 wheeler almost hit him and the service truck. This was when Pete was under the bus trying to get it adjusted to move it off the busy highway. He also said it was a lot of work to change them over, changing the inversion valve and so forth.

Now I'm really confused (I was before I started this project!) Wink.

Now I'm back to square one, only with a lot more to chew on. Sheesh! It was easier to paint the bus! Well almost anyway. But when it comes to safety I will take it a lot slower and make sure I make the right decision.

Back to the drawing board, please keep the thoughts, experiences and suggestions coming.

Paul
Logged
JohnEd
Hero Member
*****
Offline Offline

Posts: 4571




Ignore
« Reply #18 on: October 10, 2008, 09:55:40 AM »

Paul,

Now I'm really confused (I was before I started this project!)

Me too!  Good luck.  You seem to have support for going either way.

OK, the springbreak is really a bummer for getting off the road after a breakdown.  Given!  Now what are it's strong points.  Nobody reinvented this stuff to make life more difficult...right?  This isn't the Gummint.  I don't think I would rest my case on the preferance of one mech and I am not contradicting the guy.

Looking forward to hearing how this all came out.

Thanks,

John
Logged

"An uneducated vote is a treasonous act more damaging than any treachery of the battlefield.
The price of apathy towards public affairs is to be ruled by evil men." Plato
“We can easily forgive a child who is afraid of the dark; the real tragedy of life is when men are afraid of the light.”
—Pla
Dreamscape
Guest

« Reply #19 on: October 10, 2008, 10:14:00 AM »

Looking forward to hearing how this all came out.

Me Too! Grin

I agree with not taking the opinion of one guy who had problems. If I understand correctly all newer trucks and buses have spring brakes, am I wrong?!

At least the Eagle is sitting in the driveway not burning any fuel or causing a traffic jam!

Paul

Logged
Sojourner
Jesus Love You!
Hero Member
*****
Offline Offline

Posts: 894


WWW

Ignore
« Reply #20 on: October 10, 2008, 10:28:34 AM »

Good report Dreamscape.

This is a point to remember if anything go wrong with either version DD-3 or Spring Can, no need to worry about emergency diaphragm leaking with DD-3 to get rolling, but Spring Brake needs air to compress spring and hold to get rolling.

About Pete experience can happen anytime, more so when it diaphragm gets old... like 10 years ? ? ? and being in a bus is very difficult to get under. All new buses and trucks are using Spring Can. If truck lockup, all they have to do is reach to adjuster lever and remove the tension but no brake for that wheel after the slack.

I would suggest to replace emergency/park diaphragm every 5 year or so.

I am still going to change to Spring brake so I can service it for much less than DD-3

Thanks for reports.

FWIW

Sojourn for Christ, Gerald
« Last Edit: October 10, 2008, 10:34:19 AM by Sojourner » Logged

http://dalesdesigns.net/names.htm
Ps 28 Blessed be the LORD, because he hath heard the voice of my supplications. The LORD is my strength and my shield; my heart trusted in him, and I am helped: therefore my heart greatly rejoiceth; and with my song will I praise him
Sojourner
Jesus Love You!
Hero Member
*****
Offline Offline

Posts: 894


WWW

Ignore
« Reply #21 on: October 10, 2008, 10:31:55 AM »

Paul,

Now I'm really confused (I was before I started this project!)

Me too!  Good luck.  You seem to have support for going either way.

OK, the springbreak is really a bummer for getting off the road after a breakdown.  Given!  Now what are it's strong points.  Nobody reinvented this stuff to make life more difficult...right?  This isn't the Gummint.  I don't think I would rest my case on the preferance of one mech and I am not contradicting the guy.

Looking forward to hearing how this all came out.

Thanks,

John

About if the spring break is not the problem to keep it lockup....it the diaphragm blows to leak from holding spring in the compressed mode.

FWIW

Sojourn for Christ, Gerald
Logged

http://dalesdesigns.net/names.htm
Ps 28 Blessed be the LORD, because he hath heard the voice of my supplications. The LORD is my strength and my shield; my heart trusted in him, and I am helped: therefore my heart greatly rejoiceth; and with my song will I praise him
Sojourner
Jesus Love You!
Hero Member
*****
Offline Offline

Posts: 894


WWW

Ignore
« Reply #22 on: October 10, 2008, 10:41:31 AM »

About why all new air brake going spring version...I believe it the law? ? ? (check it out, we are going to KFC...hunger strike no! ) and if hose break or no air...you have emergency braking. And with DD-3 if one of 2 hose breaks that connected to an emergency storage air tank...you have NO Emergency Brake to both sides or duals....Yike!

FWIW

Sojourn for Christ, Gerald
« Last Edit: October 10, 2008, 10:48:51 AM by Sojourner » Logged

http://dalesdesigns.net/names.htm
Ps 28 Blessed be the LORD, because he hath heard the voice of my supplications. The LORD is my strength and my shield; my heart trusted in him, and I am helped: therefore my heart greatly rejoiceth; and with my song will I praise him
SmoothJazz
Jr. Member
**
Offline Offline

Posts: 78




Ignore
« Reply #23 on: October 10, 2008, 11:03:43 AM »

Hello Dreamscape,

You might give Mark or Russ at Eagle Nest Coach a call about instructions to change over to spring brakes. They may know how to do the changeover. They can be reached at 615-242-7241.
Logged
makemineatwostroke
Guest

« Reply #24 on: October 10, 2008, 11:11:16 AM »

WOW; who would ever thought that a system 30 years old and still used to this day would cause so many problem a guy driving for 50 years and had a problem with a spring brake and could not back off the slack adjuster in less than a minute and please tell me the difference in a 40,000# bus and 80,000# truck  and I would ask Norris why Eagle changed over to the spring brakes in the 70's FWIW the spring brake if adjusted to Bendix specs is not going to lock the wheel while it is in motion, only after the unit is stopped , another point is the spring brakes are available at any truck parts try that with the DD-3  have a great day
« Last Edit: October 10, 2008, 12:07:14 PM by makemineatwostroke » Logged
Don4107
Sr. Member
****
Offline Offline

Posts: 407





Ignore
« Reply #25 on: October 10, 2008, 12:56:16 PM »

It may be simplistic, but I think a list of pros and cons can help.  I have been considering the same thing even though my DD3s are still working.  My list for switching to spring brakes would look something like this.  Yours might be different.

Pro
Most current mechanics/tow operators know spring brakes, not DD3.
Cheaper to repair. 
Find replacement parts anywhere.
Less likely to be stuck in nowheresville waiting for parts.
Overall simpler system with less parts, less potential leaks.
Can afford to carry a spare can for the price of one DD3 diaphragm.
Unknown age and condition of existing DD3s.
Hitting the road with known fresh brake cans.
More drivers understand spring brakes.
I can do the change over work myself.

Con
System is currently working.
Need to modify mounts. (Not a problem for you.)
Liability of changing safety system.
Expense of changing out a working system.
Just what I need, another project on the list! Smiley

If you need to get back on the road, fix the DD3 for now and if you want to make the swap, gather the stuff to change over later.  Modifying something as important as brakes is not for the faint of heart.

Nothing here meant to start a debate on the pros and cons of DD3s vs spring brakes, they are both perfectly good safe systems, just my (sometimes feeble) thoughts.

Good luck,
Don 4107





Logged

Don 4107 Eastern Washington
1975 MCI 5B
1966 GM PD 4107 for sale
1968 GMC Carpenter
Dreamscape
Guest

« Reply #26 on: October 10, 2008, 01:19:58 PM »

Don,

Thanks for your comment. My list of pros and cons are very similar, but differant if you know what I mean.

I will continue to evaluate the situation and decide which way to go. I would rather not tackle either system until I have all my ducks in a row!

When I do this I want it to be for the long term, as I really need to finish a few things to make my other half happy! Wink

Everyone that has contributed I say "Thank You" great answers from knowledgeable bus nuts. My biggest problem is this, I aggree with everyone!  Grin Now how do I determine which way to go without too much trouble?

I think that the valving and/or air routing is where my questions lie. I have not received a real deffinate answer on what is needed to change them over from DD-3 to Spring type. Because the working air principle is the opposite on both, would you not need a differant type valve or foot pedal valve? I would have a better idea if I had a manual for a newer Eagle that has spring brakes, then I could research the part number and air line routing etc..

Keep 'em comin', The jury is still out!

Paul
« Last Edit: October 10, 2008, 01:41:46 PM by Dreamscape » Logged
johns4104s
Hero Member
*****
Offline Offline

Posts: 865





Ignore
« Reply #27 on: October 12, 2008, 07:20:34 PM »

Paul,

I added spring breaks to my 4104 20 years ago. However it was single can braking system with the ICC parking break that would let the bus roll if the air bled down.
All I had to do was add a 1) air line to go to the 2)front dead man switch to the rear. and split ,at a 3)one way valve to go to each 4)spring break can at each wheel. $100.
The only problem was that due to adding the spring can to each wheel it limited the room you have to get the tool into the can to manually back of the spring. I just shortend the tool and it went in. But I always carry an auxiliary electrical air compressor, so as long as it was not a bad can diafram I could always use the compressor to back of the spring.
Now, on my way home from your great rally I had a problem with my MCI/DD3  drive Axel drivers side, the brake started to bind. I pulled the wheels, backed off the slack adjuster and came home without a problem.
The board input was lack of maintainence, which is very possible. However I do not want to be on the road with more DD3 brake problems.
No one on the board knew if there is enough room on the MCI 9 to fit the extra spring can. unfortunately when I had the wheels of I did not check for room. But if I have to weld? I do not really want to weld /move the brackets so I am also in a Delmer??
I will keep you informed on my research..

John
Logged
buswarrior
Hero Member
*****
Offline Offline

Posts: 3571


'75 MC8 8V71 HT740




Ignore
« Reply #28 on: October 12, 2008, 08:45:36 PM »

oh fiddle faddle.

Now that we're this many years deep into litigation hell, I doubt anyone will tell us how to convert, or will say it is a good thing, bad thing, or anything else. We're on our own.

Any advice you get, and, I guess to be fair, best to consider mine included, must be regarded with a great deal of scepticism, because just what training or experience has the advice giver had in the realm of brake design?

Mechanics, in particular, must NOT be trusted, without some other back-up as to their thoughts. They have been trained, maybe, by whom, only God knows, in parts replacement, not system design!!!
  Engineers design brake systems, mechanics change the parts when they break.

Can anyone remember the keyboard commands for the old Windows 3.1?  Well, how many of the guys who worked on the old stuff back when it was in commercial service remember what was what? Even when you did stuff day in and day out, once out of practise, you forget stuff.

Don't get me wrong, I'm not talking down on anyone, but just who amongst your classmates in high school was taking auto? A few inspired car nuts, but then a bunch of "others".  And now you blindly follow whose words of advice regarding messing with the engineering of the braking system on your coach? Read between the lines further up in this thread, the conversion that went wrong was caused completely by a mechanic who fooled someone into thinking he knew what he was doing, and took his ca$h.

Sorry, I'll get off my soapbox, pet peeve of mine, seeing folks getting ripped off by pretenders.

Anyway, procrastinator that I am, I have to repair one of my DD3 chambers in the push to prepare for the great journey to Jack's party.... boot was torn, grease zerk broken off, finally beginning to get sloppy on the release... don't ask, I'm signing up for one of those 12 step programs...no, Niles, it's ok, not AA....

With some luck, I have two days this week, so I'll try to get it in the air and start removal.

If the new air lines I installed with lots of anti-seize a few years back when I freshened up the inversion valve, parking regulator and the lines, come off cleanly, I'll see if I can plumb up a spring chamber to the existing circuits to see how bad the timing is, set up the way I suggested back there somewhere in this thread.

Trying to get to the bottom of this academic question.....How's that for some motivation to get on with it?

For the MCI owners that might be wondering, there is insufficient room to fit a spring chamber in the MC7/8/9, as the configuration of all the axle/suspension/brake components has been chosen taking advantage of the DD3's small size. You will notice that the back of the DD3 is quite close to a suspension part. A spring chamber is fatter in the back half and longer than a DD3. Without welding new brackets elsewhere around the axle circumference, and re-orienting the brake linkage, you can't just swap spring chambers in.

And, there's nothing wrong with DD3 or with spring brakes. They are two ways of accomplishing the same goal: the bus doesn't roll away while you are sleeping in it!

happy coaching!
buswarrior

Logged

Frozen North, Greater Toronto Area
Tony LEE
Sr. Member
****
Offline Offline

Posts: 392



WWW

Ignore
« Reply #29 on: October 13, 2008, 02:59:25 AM »

I have a couple of problems with DD3 brakes generally.
First is that if the rollers aren't locking correctly you can set the brake with air up and it holds on my levelling ramps very well. Can even try driving the bus to make sure they are holding.  Then about three in the morning there is a terrible creaking noise as the air pressure finally bleeds right off and one DD3 is no longer holding - and the bus just rolls slowly off the levelling ramp. Happened twice - first time bent my A-frame that I had tucked between the drive and tag wheels out of the way. I thought I must have had the bus parked right on the end of the ramp and maybe it sank into the dirt.  Second time moved about a yard. I finally did realise what the problem was and did service the brake and have had no more problems - BUT I chock the wheels at all times as if I have no parking brake.  Real confidence booster isn't it - especially when hearing other stories of moving MCIs.
With a spring brake, once it is set, it stays set unless the spring breaks - and why should it break when it is under less stress set than when it is released. Check by driving against the brakes and if it holds, it should continue to hold.
Second problem is that here we have to put all heavy vehicles over the Roads and Transport Authority pits every year. They subject it to some terrible torture - by moving plates that the wheels are on forwards and backwards and side to side - and testing the brakes statically and dynamically - etc etc.  And of course they want you to pump the brake system down to 60 psi, set the park brake and THEN demonstrate that you can release and reapply the park brake another two times.  Can do it with a maxi-brake, but not with DD3. Young hot-shots have never heard of a DD3 and even after ringing head office and finding their oldest adviser who might know about them, and studying my drivers and workshop manual, they sometimes throw up their hands and wave me on - or sometimes they bung a defect on it because it doesn't comply with the appropriate design rules.  Of course my mechanic just signs off the defect and it is good til next time but it's all a bit of a pain. Maxi brakes they understand, I understand and every truck mechanic in Australia understands.  DD3 brakes - I understand and maybe about half of the very small number of MCI owners also understand, but hardly anyone else.

If anyone can point me to any info about converting MC8 DD3s to maxis, I would be really pleased - and would sleep much better once they have been changed.
« Last Edit: October 13, 2008, 03:01:19 AM by Tony LEE » Logged

Dreamscape
Guest

« Reply #30 on: October 13, 2008, 03:35:35 AM »

Sojourner,

I posted my question on an Eagle Bus Nuts Group and had a couple of replies. One said he had the diagram for switching from DD-3's to spring brakes, the other said that he did it several years ago and it was not a big deal and would post how he did it. He had to go look at his coach to refresh his memory.

I will let you know what I find out.

If I don't hear anything back by this Friday, I'm going to order the kit for the DD-3's from Norris and get on with it.

Going to take apart the one suspected can today, and see where the real problem is.

John,

Glad you enjoyed the rally! I have one question, why did you remove the wheels when you had the problem? You said to make an adjustment to the slacks. I always thought you did that with the wheels on, just curious.

There is a ton of room on Eagles to make the change. I have never seen an MCI so I will leave that up to the experts.

Good Luck and let us know how you come out,

Paul
Logged
niles500
Niles500
Hero Member
*****
Offline Offline

Posts: 1188


ROSIE




Ignore
« Reply #31 on: October 13, 2008, 07:34:05 AM »

...no, Niles, it's ok, not AA....

Jeez - you scared me there - thought I was loosing another drinking buddy sponsor  Cry
Logged

(\__/)
(='.'=)
(")_(")  

- Niles
Pages: 1 2 3 [All]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.18 | SMF © 2013, Simple Machines Valid XHTML 1.0! Valid CSS!