B400 retarder question

[jmblake]

We just got back from another short trial trip this weekend and I got the retarder wired up before we left and on the way it wouldn't work so I figured I had missed something, then we started home today and was coming upon a stop light and wala it was working Didn't do anything to it to make it work so I don't know could it have had a air pocket in the fluid The transmission did set for several months with no oil and the retarder accumulator was drained also, I just don't know why it started working all of a sudden. Then another question it seems like it doesn't come one like the jake did as soon as you let off the fuel peddle. it seems to have a bout a 10 second delay from the time you let off the peddle till it comes on. also does the air line need a regulator on it that goes to the accumulator?
I just don't remember how it acted when I brought the donner bus home about 4 months ago, getting old I guess lol
Thanks Jason

[HB of CJ]

Sometimes they can be wired up through the brake light circuit?  That would mean for it to work one would have to step on the brake pedal?

Don't retarders, regardless of type, now need to wired up through the brake lights so that when they are operating the brakes lights come on?

[LuckyChow]

That's an option in the transmission computer.  I don't know if there's a legal issue or not.  Mine activates the brake lights, but the ones at work do not.  They operate a "decel" pair of lights.

[jmblake]

I know mine isn't wired into the brake lights.
Jason

[Scott & Heather]

Jason, I can't speak specifically for your tranny but our 748 retarder does indeed have an air regulator and it needs to be adjusted correctly. I don't know the air pressure spec but ours was set incorrectly and the retarder wasn't disengaging and I was forced to turn the regulator pressure down to zero effectively disabling the retarder. I don't have time to sort out the issue right now so I'll be tackling that project next year likely.


Sent from my iPhone using Tapatalk