Who's got DD3's?

[bevans6]

I seem to be rebuilding not only my engine but the whole arse end of my bus, and I have skanky looking DD3's and hoses that have been on there way too long.  I'm gonna call Luke in the AM on Monday, but who else has DD3's?  My quasi plan is get rebuilds, and  save the cores or rebuild them as spares.  Someone said call MCI - has anyone asked if they have DD3's lately?

Thanks, Brian

BTW, if you ever install an engine in a MC-5C, make sure you prop the driveshaft up.  If you don't you spend all Saturday morning figuring out how to get it unhooked from under the flange on the transmission.  Answer - chassis up all the way, axle in full droop, undo all of the engine hold-down U-bolts and jack the gearbox up a quarter inch.  What a PITA...

Brian

[luvrbus]

Brian,I have a friend that this winter we are going to install wedge springs on his 9 from a Mack truck he is tried of fooling with the DD3.
I have another friend I can put you in touch with that just removed his DD3's one just needs a diaphragm he will probably make you a deal

good luck

[Lin]

I don't remember what rebuilt DD3's cost.  I think it was around $400. each.  There are rebuild kits though.  Ask Luke about that also.  I don't think you need any special equipment to do it, and the springs are not heavily loaded.  If Clifford's friend has good take offs, that may be a real deal.

[luvrbus]

MCI charges $525.00 plus a $375.00 core deposit for the DD3's the Transit models are $475.00

good luck

[gus]

My 4104 has regular spring brakes, the 4107 has DD3. The DD3 is a pain in the neck, regular wins hands down.

[Ericbsc]

I have a pair that I just removed from my 05 eagle. They were working fine when I removed them a couple months ago. I changed the entire axle and the new one has springs. P.M. me if you are interested.

[luvrbus]

What did you do Eric change to a model 10 for the wider shoes ? Ed Brenner probably has a set too he changed over to springs on his Eagle a few years ago Manny should have a set also.

I sold 12 DD3's to a rebuilder in CA for 200 bucks each they are starting to get a little pricey and a good diaphragm is over a 100 bucks now if you can find a Bendix diaphragm Mohawk had Chinese made diaphragms for 80 bucks not long ago that all I could find so I sold the cores.

Brian last I checked Kirks was about 100 bucks ea cheaper than most places for the rebuilt DD3's but he was out of the left side

I have 2 new ones not rebuilt still in the box just waiting for some sucker lol  

Eagle people seem have those things laying around,kinda goes against Belfert's idea you shouldn't change the OEM brake system

good luck

[bevans6]

I know you don't like PM's, so seeing as I've been known to be a sucker, what do you want for your two new DD3's, presuming they are a pair?

Brian

[luvrbus]

Brian, I need really to keep mine for the school and I was joking about the sucker lol but will sell them maybe.
I will tell you where I bought the new set for $575.00 each.

You are not going to believe it but he had plenty of new ones not his rebuilt jobs and that is REI yea the same REI of the Chaz post I never said I didn't buy new stuff from there I just don't buy his rebuilt crap lol 

good luck

[wal1809]

I googled DD3 and I still have zero clue as to what yall are talking about.  Can someone inmform the ignant party here?

[trucktramp]

DD3 is a brake chamber.  Not like what you see on your everyday semi truck and much more pricey.

[Jerry Wilson]

I know it can't be done but some how it just  happened,  I cut the old dd3 brackets off and welded on spring brakes plus changed around the air valves. We had an incident where the old emergency braking system didn't work[was exciting]But decided that was enough of a 40 year old design.10.000 miles  later i still think it's the best thing  to do      Jerry wilson  1966 4107

[bobofthenorth]

I googled DD3 and I still have zero clue as to what yall are talking about.  Can someone inmform the ignant party here?

Just to expand a bit on the explanation already posted, DD3 are non-spring parking brake chambers that incorporate a locking mechanism so that when the system air bleeds off the brakes stay applied.  I don't have them and from what I've read/heard I'm really glad I don't and I don't understand why anyone who does have them wouldn't make the effort to change to maxis.

[bevans6]

Thanks to all, i have some leads to follow up on tomorrow.  Ideally  new, because I rarely put a rebuilt anything in a brake system (just a habit I have from racing).  I was extremely disappointed and quite embarrassed when I got the first brake chamber out.  The parking brake and locking port lines were, to put it mildly, about 10 or 15 years past their sell-by date.  They were completely stiff, the outer layer fell off when I bent them, and where they were clipped to the differential the outer layer and the steel braid was completely gone.  I took one chamber off, took it apart, and it was in sad shape.  Diaphragm cracked, etc.  Really time for new ones.

Questions;

The main brake line is pipe thread at both ends.  I have no idea what the correct way is to fasten or unfasten a line that is pipe thread at both ends, the line can't rotate.  I undid the hose clamping part, but I don't know if that is right.

The DD3 clamping rollers ride on a steel ring that is pressed or fitted into the aluminium housing.  You can't get the locking piston out with that ring in the way.  What is the technique for removing that ring?

thanks, as always, excellent advice and feedback that I always try to reciprocate on when I know something that might help someone else.

Cheers, Brian

With honour and respect to the heroes of 911, on this day.

[bwze]

bevans6, I rebuilt my DD3's back around first of the year. Got most of my parts from Luke and the process was pretty painless. That steel ring that you're talking about should just slide out of the bore after you remove the plastic retainer (held in place by four bolts). Mine did not want to come out easy, but I finagled it out. If memory serves me correct, after i removed the push plate and rod and the plastic retainer, I "gently" tapped the exit side of the housing against a piece of sacrificial wood and the ring eventually gave way.

As far as the brake lines are concerned, again mine were the same way. I just cut them after finding replacements, I found suitable ones from Grainger with swivels on the end and the mating fittings.