Question for DD-3 to Spring Brakes on an Eagle 01

[Dreamscape]

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.

Thanks in advance for the help,

Paul

[Sojourner]

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

[Dreamscape]

Jerry,

Thank You for the information. 

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

[Sojourner]

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.

[Dreamscape]

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

[FloridaCliff]

Paul,

Call me later.

I will IM my number.

I have repaired and replaced several times.

Cliff

[Dreamscape]

Got it! When is the best time to call?

[luvrbus]

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

[Dreamscape]

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. 

Paul

[luvrbus]

Paul, I'll check Friday if I have a set I will ship them to you good luck

[JackConrad]

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

[buswarrior]

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

[Dreamscape]

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

[Sojourner]

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

[Dreamscape]

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