Converting 102c3 brakes from DD3 to spring brakes
 

Converting 102c3 brakes from DD3 to spring brakes

Started by blue_goose, October 12, 2018, 02:49:22 PM

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blue_goose

Has anyone made this change and if so what did it take to make the upgrade?
Jack

chessie4905

First thing you have to do is see if there is sufficient clearance between of end of dd3 and bulkhead. The shortest maxi brake chamber is approx 1 1/2 to 2 inches longer. You also need room to install the caging bolt to release them for towing. On GMC's, except for 4104, there isn't enough room. Body or mounting bracket surgery would be required.
In any case there will be valve, line, and other components removal, and rerouting of air lines at back.
GMC h8h 649#028 (4905)
Pennsylvania-central

ol713


   Hi;
      Question;    Why would you consider this change?  If you rebuild your
      DD-3's,  they will be good for years and years.  That would mean no
      re-engineering the coach and less money required.
                                      Good luck,    Merle

luvrbus

Jack,never done a C but the spring brakes are 9 inches long,the C was a transition model if the C is like the D with out the air beam it is a easy change.Plumbing is nothing you use what you have just switching ports on the relay.If the C has a air beam like the older MCI there is not enough room without moving the brackets and longer S cams.You could check into the MGM that have a rotatable piggy back to get enough room maybe         
Life is short drink the good wine first

blue_goose

I have never spent any time working on changing anything on air brakes.  Did put new DD3's on my Eagle and replaced the brake pads. Didn't take any knowledge of how they worked to do that. 
We started to leave last week and when I got on the road the compressor wasn't keeping up with the air demand.  When I found a place to get off the road I found air coming out of the lower chamber of the brake air valve.  I thought the air valve was bad so on with a new one, what a job that was.  New E-10 valve and same problem.  Now I did more testing and found when the parking brake valve is off the air doesn't come out of the brake valve.  If it is only a parking brake problem with the DD3's the compressor should have been keeping my air up on the road. 
Well today I am going to get it on the ramps and see what I find in the rear.  If any of you have any idea's please post them here.
Jack

luvrbus

Jack,if you have room there is nothing to it,all it in-tales is reversing the air flow direction,spring brakes need a air supply to release and the DD-3 need air to set 
Life is short drink the good wine first

eagle19952

Quote from: luvrbus on October 13, 2018, 06:08:32 AM
Jack,if you have room there is nothing to it,all it in-tales is reversing the air flow direction,spring brakes need a air supply to release and the DD-3 need air to set

Properly operating DD3's are better.
don't understand why anyone would want to convert.
Donald PH
1978 Model 05 Eagle w/Torsilastic Suspension,8V71 N, DD, Allison on 24.5's 12kw Kubota.

luvrbus

Quote from: eagle19952 on October 13, 2018, 08:05:08 AM
Properly operating DD3's are better.
don't understand why anyone would want to convert.

Availability and price plus the DD-3 are only found on a bus so the price greatly reflects that ,Eagle have had spring brakes since the 80's fwiw
 
Life is short drink the good wine first

Geoff

Spring brakes are good with a manual transmission if you have to start going on a hill.
Geoff
'82 RTS AZ

richard5933

Quote from: Geoff on October 13, 2018, 11:25:42 AM
Spring brakes are good with a manual transmission if you have to start going on a hill.
Never having had spring brakes, could you explain?
Richard
1974 GMC P8M4108a-125 Custom Coach "Land Cruiser" (Sold)
1964 GM PD4106-2412 (Former Bus)
1994 Airstream Excella 25-ft w/ 1999 Suburban 2500
Located in beautiful Wisconsin

Lee Bradley

You set the spring brakes. Select the gear you want, bring the clutch to the engage point and hit the brake release button, engage the clutch and roll away.

eagle19952

Quote from: Geoff on October 13, 2018, 11:25:42 AM
Spring brakes are good with a manual transmission if you have to start going on a hill.

I guess. Hill holder brakes...
Donald PH
1978 Model 05 Eagle w/Torsilastic Suspension,8V71 N, DD, Allison on 24.5's 12kw Kubota.

eagle19952

Quote from: eagle19952 on October 13, 2018, 08:05:08 AM
Properly operating DD3's are better.
don't understand why anyone would want to convert.

IIRC Euclid used them too, way back when.
Donald PH
1978 Model 05 Eagle w/Torsilastic Suspension,8V71 N, DD, Allison on 24.5's 12kw Kubota.

Sebulba

Back to the U.S. after 8 years in Europe.  
Bought a 1997 MCI 102D3 with Allison B500 on November 17, 2021 in Syracuse, NY.  Commenced living it that day and  drove it to Florida and New Mexico.  Converting as we go.  https://basicsuds.com

richard5933

O. IC. Did not know that. Guess it's not necessary to apply the service brakes to disengage the parking brake with spring brakes. That would be helpful.
Richard
1974 GMC P8M4108a-125 Custom Coach "Land Cruiser" (Sold)
1964 GM PD4106-2412 (Former Bus)
1994 Airstream Excella 25-ft w/ 1999 Suburban 2500
Located in beautiful Wisconsin