1998 U270: Retarder has been working last several days when I let off the throttle, now it only works when I put on the brake, what changed?
If you have a joystick and don't put it all the way back when you take your foot
of the throttle the retarder will come on to what ever position you have left the
joystick in. Some people drive that way I prefer to use the joystick.
If your 'retarder' button is on, but the joystick is all the way forward in position 0, it will only activate as you apply the brakes. You need to pull it back at least one click for it to activate when you take your foot off the gas. After that, the more clicks back you pull it, the more it engages when your foot comes off the pedal.
At highway speeds, the last position on mine will damn near throw the dog across the living room.
Thanks Elliott I forgot all about the retarder switch as I never touch it, it's always
on.
Switch on always except in slick conditions. Snow, ice, heavy rain (yes a 32,000 bus can hydroplane on those four large rather significant contact patches on the rear tire) Once those rear tires loose adhesion, the heavy dnd wants to Change it's seat and lead, at that point you are definitely along for the ride.
And it is scary, had it happen once, bus sideways on a four lane highway at 45 mph in pouring rain.
Tim Fiedler
Gen-Pro.biz
630 240-9139
And if you leave the retarder joystick in any position except off, fully forward, your cruise control will not engage.
Actually the cruise will engage, but the first time it has to "let off" due to a downgrade, the retarder will turn on, tap the brake lights and turn off the cruise.
There are no (very few perhaps) universal answers when it comes to what happens in one year or another, one model to another in the same year. Forest's experience might be as he describes it. Keith's may also be as he sees it. Four years difference.
In my coach, a 2001 U320, if the joystick is in any position other than zero when the throttle goes to zero either by taking your foot off the throttle pedal or while using cruise control, starting down a grade the retarder begins to retard and if you are using cruise control, it will disengage.
I had inadvertently left the retarder joy stick in position one and saw the cruise control disengage every time we went over the crest of a hill. Took a while to realize the joy stick was not in the full forward position.
My preference is switch on, joystick fully forward unless on a long downhill grade.
This is what I do now. I will likely add a switch at some point, that will allow me to break the connection between the brake switch due to retarder activation for those instances where I am towing and don't want the brake controller to activate the trailer brakes based on retarder usage...but then can flip the switch on when not towing.
I put in an extra pressure switch to activate the trailer brakes so the trailer brakes only
come one with the brakes.
I have a '95 U-240. There is a retarder switch with a light that come on if the switch is on and you touch the brake, but no "Joystick". did that come later?
Joe
The joystick is associated with the Allison transmission retarder. Your U240 came most likely from the factory with a an exhaust brake. The switch is just labeled as a retarder
No, the 1995 U240 COULD have a transmission retarder.
And, in that era, the joy stick was an option and some have been able to retrofit one.
Our 1995 U280 came with retarder but no joystick.
So, I upgraded to a joystick also. One of the very best upgrades I have done. Kind of a 4 way tie between the hose reel, lithium batteries. Solar power and the Alison joystick.
Wow, great info, left this morning and it was working like it should.