Another retarder question

[rayshound]

I had posted earlier on the oil coolers for the HTB-748 ATEC hooked on a DDEC 4 series 60. Got good answer so now my next milestone. The transmission was out of a 91 Eagle. I don't know what type of (switch  or actuator) is used to apply the retarder. It is a electronic transmission and I have the ATEC manual but it doesn't address the retarder. Do you use a sol. valve and a switch and get a air siginal off of the air brakes? Do you use a varible air switch or a seperate air pedal? The retarder has a 3/8" air line going to a valve body.
Another question same subject may apply to what I'm trying to do above. The series 60 is a 12.7 with the 3 stage pac brakes. I have all the stuff for the engine. I have the dash switches and can use the electronic cruise control to work with the jakes. My question is pac brakes & retarder, any thoughts or ideas to maybe select one or the other or just use retarder as a stand alone?
                                   Many Thanks Ray

[TomC]

Actually, both have a distinct function and usability, that I would keep both on.  But---don't use both at the same time-would be to powerful and could twist the drive train.  My suggestion would be to set up both properly to work-with the retarder set up to work both manually and also automatically with the brakes around town.  Then you'd also have the Jakes (PacBrake) for highway use going down long grades (which a hydraulic retarder is not very well suited for-heats up the trans fluid to much).  I would install three toggles on the dash. The first one being a on-off-on switch that would allow you to choose either the retarder or jake but not both.  The second switch would be for the retarder to select between automatic use activated by the brakes or the other position to use the manual dash switch (usually a 5 position switch that has a long handle on it-like a trolley brake).  The third switch for the 6-4-2 selector for the Jake.
As to the hook up of the Allison retarder, best ask Allison.  Hope this helps some. Good Luck, TomC

[Clarke Echols]

I'm not 1000% certain, but I think the retarder runs off of air pressure from the brake treadle valve.
I know the retarding force is proportional to how hard I mash on the treadle in my Neoplan that
runs a Series 50 on an HTB-748 Allison.

Clarke

[rayshound]

Thanks Guys, I appreciate the info. I guess I'll need to find someone with a p&id from  a bus with one installed & has the manual. I'm thinking that the air siginal from the air brakes would be a varible and give a proportional siginal to the retarder. A switch would interupt the air siginal to the retarder. Maybe 3 or more 12vdc sol valves with a regulator each set at different pressures could give you different percentages of application. I'll keep searching and maybe more ideas?  Thanks Ray

[Sammy]

I've seen 3 different retarder control setups - first had 3 different pressure switches fed from an air signal from the brake apple valve, second was a variable control that looks lika a small directional lever on the steering column, third kind was mounted between the brake apple valve plunger and the actual valve, it was an additional section with micro switches it.All had a retarder control module - small black box with a wire harness on it. I would have to do some more homework to dig up wiring diagrams.
Let me know which one you are interested in, I'll see what info I might have. Best of luck with your repower. 

[rayshound]

Yes Sammy I would appreciate any info at all on the retarder hook up, the air or electric end. Thanks Ray

[rayshound]

Sorry Sammy, I would be interested in the three pressure switch hook up.  Ray