Left Atlanta this morning and an hour after departure the retarder started failing. Worked okay for the first few stops but noticed that it took the full throw of 6 clicks to get any braking action. Didn't notice is the retard light was coming on or not. A few stops later, nada. No light, no retard. Stayed that way most of the day, and at a rest stop, I pulled the panel below the console and checked connectors, pulled the retard switch and tested it...okay...Oki-gaurd the connectors and reinsalled....and sprayed WD40 on the cannon plugs on the tranny...pretty much all I could do in the downpours. After parking tonight, I explored deeper into the console to confirm all the plugs were in place and checked for a relay....none to be found, but did find a few under the dash cover...pulled the connectors and applied some Oxi-guard and put em back. Hope that solves the issue, because I have fallen in love with the retarder, and it really sucked not having it on the hills in Tennessee and the back roads. Will update if those measures fixed it. I really, really hate chasing electrons and dread replacing rotor and pads by the time I get back to Montana. Woody. P.S. FWIW, traffic is incredibly light on the freeways and back roads, thanks to the hysteria over toilet paper!!!
I love the retarder too but I would use extreme caution using retarder in rainy or snowy weather. There is potential to lose traction on rear wheels causing loss of control.
Make sure the trans fluid isn't low,is easy check.
Pyoler, not sure why your retarder is not working, but so others so not use retarder in the rain:
Recently when buying 22.5 tires for a commercial truck I own, the truck tire shop manager asked if I drove much in the rain, showed me data on tire traction ratings, different models from same mfg, why some models are not recommended for drive wheels, steer only, or for both.
And then there is this post from another thread. "Let me tell you what can happen when you drive on a rain slick road with the exhaust brake engaged. (Retarder would be similar) I was going south out of Corpus Christi in our then new 1996 36' Discovery just after a heavy downpour that had let up to a light mist. It was on a two lane asphalt road and I had just crossed a bridge over a canal. I was going 40 mph and let off the power for a slight curve after the bridge. The EB engaged and immediately shifted to a lower gear. When that happened, the rear wheels broke loose and I found myself sliding broadside taking up half of the other lane with an oncoming car. I instinctively turned into the slide and applied a little power which disengaged the EB and shifted up a gear. The coach came back into my lane and the car went past. It scared the cra* out of me, my wife and 14 year old grandson. That was 12 years ago and all of us remember it like it was last week. Now whenever we're driving in the rain, my wife reminds me to turn the EB off along with the cruise control. We like safety better than stupidity. So the next time some unknowing expert tells you that running with the EB on when the roads are wet is not a problem, tell him he doesn't have a clue as to what can happen."
That's why I like to control the retarder and not have it come on with the throttle. I use the retarder in the snow and just like brakes
very softly.
That's why Jakes get a BIG plus. I keep it on all the time and am the one that downshifts, not the computer.
Pierce
Should have labeled the thread "Retarder died AFTER DRIVING in heavy rain". I did read the owners manual and am from Montana...know better than to bypass the anti-lock system on slick roads, but also know that ABS on icy roads is not the catch all, still gotta plan ahead...seen lots and lots of wrecks on snow pack where the ABS might have made situations worse by preventing any braking. But thanks for the concerns and advice for those less experienced with stopping heavy loads on other than dry asphalt.
Update: after driving a whole day on bone dry pavement, the retarder started working again this afternoon about 100 miles from HWH. Most likely the cannon plug on the retarder solenoid suffers from water intrusion and corrosion, so will pull that apart and lube tomorrow after HWH is finished fixin the leveling system. I restate that the retarder is my favorite feature when driving the coach and it takes a lot of relearning if it suddenly quits working. Woody.
Glad your back to normal, let us know if you find anything which stands out so that the rest of us can take preventative action.
Larry
Update. Retarder continued to intermittently fail (no light, no function) after I got home. I pulled every single connector I could find and applied oxy-guard to the contacts...no change.
Pulled the following codes from the Allison display: 4626; Solenoid Overcorrect, 4226; Short to Batt, and 4526; Open. So I ordered a replacement Solenoid off of eBay for $100 Allison 29557354 for sale online | eBay (https://www.ebay.com/itm/Allison-retarder-solenoid-12v-29557354/153925334455?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649) and installed it using the work arounds found here on this amazing forum. . To my amazement, that fixed the problem. Test drive today for 30 minutes with a couple dozen stops revealed a "new" retarder. I actually can feel the difference between each click of the stick. FYI, the old retarder solenoid was packed with white powder. Wonder where that came from???? Happy camper. Woody.
If it was in the air passages it is desiccant from the dryer.
And, if it got there, likely in many other places in your suspension and brake system!
Open the wet tank drain and tell us what you get (driver's side just in front of the rear wheel).
My question was facetious...discovered the dreaded white powder blowing out of the wet tank drain a year ago. Have been chasing the desiccant gremlins since.
In that case one more gremlin gone.
Can you post where this solenoid is located
Keith
Keith, it's the solenoid on the rear of the retarder accumulator...lower passenger side of the engine on mine. One air line and a 2 pin connector. Here's the link on the old Beamalarm site that I referenced. I also needed to lower the aft end of the accumulator bracket to thread in the new solenoid as it didn't clear the steel bracket.
Replacing transmission retarder valve (https://wiki.foreforums.com/doku.php?id=technical:transmission:retardervalve)
Are you having the same trouble?
Ours will work one time then the next it won't. Sometimes after we stop at a rest area and take back off it won't work. Sometimes quits traveling down the road. I wonder if this would fix it.
Gonna check it out but the cheap replacement on eBay listed above is sold out
Some previous forum comments mention taking the solenoid off and cleaning it with good results. You could try that first. I opted to replace it since I got electrical fault codes and luckily found the cheap part.
How did you get fault codes?
With key on, parking brake set, press up and down arrows simultaneously, twice. Here's the Allison link:
http://www.mwrench.com/barth/Allison/Allison%20codes.pdf
ALLISON VALVE ASSEMBLY-SOLENOID, RETARDER 29557354 | eBay (https://www.ebay.com/itm/ALLISON-VALVE-ASSEMBLY-SOLENOID-RETARDER-29557354/303519672725?epid=2085987857&hash=item46ab2ea995:g:G8IAAOSw~AVdeo4w)
I said cheap replacement like the one pyolet got above for 100 bucks..... I saw this $357 one
I waited for 3 months before the $100 unit popped up. Just gotta be patient and keep checking eBay and Amazon.