Brake Question

[Bussman84]

I noticed one of my rear drive brake chambers leaking pretty bad this evening. (1979 MC-9) I need to get this fixed as soon as possible since we are needing to head out in a couple weeks. My question is are the rear chambers, if stock going to be the DD3? Also what are the front and tag chambers going to be called? My plan is to go ahead and do diaphrams in all 6 while I'm doing it and just get it over with just trying to figure out what to ask for when I start calling for parts does anyone think these are something that my local big rig shop will carry? I would normally just call Luke but would like to try to find local ASAP if possible. OK I think that might have been more than one question! Thanks in advance any help, as always is greatly appreciated.

                Billy

[buswarrior]

Yes, your MC9 will have DD3 chambers on the drive axles.

The steer and tag have boring plain service chambers, familiar to all and sundry...

DD3 diaphragms are not usually an on-the-shelf item unless the vendor is a regular supplier to the coach industry.
In fact, most of the truck vendors won't know what you are talking about...

Many report they get their DD3 diaphragms from Mohawk.

The diaphragms for steer and tag chambers are available all over, and I wouldn't take the time messing with those ones unless you have nothing else to do leading to your trip. Fairly accessible on the road, if they act up.

How were you going to access your DD3 chambers? I prefer to pull the wheels off.

happy coaching!
buswarrior

[bevans6]

When I did my DD3's last fall the aluminium cannisters and interior guts were too corroded to rebuild.  I bought brand new DD3's from REI, who has them manufactured after-market, and he also has rebuilt using the same parts.  So far I am very happy with mine.  I would not rebuild the standard cannisters, they are too cheap to buy new - my local truck parts has them on for under $50 all the time.

Brian

[Bussman84]

Thanks for the info. I was (am) hoping that I could access these with out pulling the wheels off but that is what I will do if need be the real kicker on that note is I just had all the tires and wheels off last week putting on new tires and wheels  Oh well that seems to be the way that usually works!

Brian, who is your local truck parts place? I read through the archives and everyone was talking about $400.00 each to replace the whole unit.

       Thanks again, Billy

[Bussman84]

Brian, my appolagies after rereading your post a couple of times everything clicked and suddenly made sense.  Again thanks for the replies. Replacing the standard canisters seems to be a good idea.

Are all dd3's going to be the same size or will I need specific information off of mine?

     Thanks Billy

[Cary and Don]

We did ours without taking the wheels off.  You have to do it on your back though.  We took the diaphragm to Napa and they had one in a couple days.  I think the ran about $35 each from them.

Don and Cary
1973 05 Eagle
GM 4107
Neoplan AN340

[bevans6]

All bus DD3's are 30 inches.  Sizes for the steer and tag axles vary a bit.  Removing the wheels is the way I would go - I ended up replacing all of the lines, and the inversion valve while I was in there.  Some of the lines were just disgusting - and this coach had recently passed a DOT inspection for change of ownership!  I had to cut the old clevis pins to the slack adjusters off with a grinder.  Nothing like working on old stuff...

Brina