| Author | Message | ||
| Grant Thiessen (Busshawg)
Registered Member Username: Busshawg Post Number: 41 Registered: 10-2007 Posted From: 206.45.93.160 Rating: N/A |
Hello guys, once again I'm looking for some advice. After a little better than a year of working on my MC9 we managed to take it out on the week-end. It was the first time my wife said this is actually going to be alright!! Was nice to get it out although it's not quite complete. Anyway before we left I had to rewire my tail lights due to the fact that the previous owner had kind of messed up the wiring. Well I had all the lights working perfect but when I went to move the bus it wasn't building air. It has always worked well proir to this, moving it around or just taking it for a a few mile ride. Now it seems to build after 90lbs but below 90 it just doesn't pump. The air dryer is giving off air in very quick little spirts. When I cover the purge valve (with my hand) on the drier forcing it to build air it will operate properly after a short while and away I go. Now my question is did I do something wrong with my wiring on my tail lights? Is there some sort of electrical connection that is fed to my drier or air regulator through my tail lights? Or is it just a coinsidence that I possibly have some crap in my purge valve causing it to not operate properly. Thanks in advance to ALL of your responces. | ||
| Jack Conrad (Jackconrad)
Registered Member Username: Jackconrad Post Number: 826 Registered: 12-2000 Posted From: 76.3.173.51  Rating: N/A |
Probably just a coincidence. Only wire I have ever seen on an air drier was for an optional heater. Jack | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 533 Registered: 8-2006 Posted From: 74.32.91.40 Rating: N/A |
Grant, change your air compressor governor and service the the air dryer could be either one causing the problem.If the air dryer has not been serviced in the last year that is where I would start and Jack is right the wire is for the heater | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 543 Registered: 8-2006 Posted From: 207.231.75.253 Rating: N/A |
Grant, Follow the excellent advice above, and think of this. Your bus has a protection valve which will not allow air into the auxiliary portion of the system until the pressure is above about 80 psi in the brake reservoirs. So, the pressure SHOULD build quickly to about 80, then slow down as the air ride system pressurizes, and the bus stands up. As yours isn't, look at the dryer and the governor, as suggested above. If the dryer is putting out what seems like a lot of air, it sounds like the problem. Good luck hunting, and please post back with what you find. Regards, George | ||
| Grant Thiessen (Busshawg)
Registered Member Username: Busshawg Post Number: 42 Registered: 10-2007 Posted From: 206.45.93.160 Rating: N/A |
Thanks guys, This was the way I was leaning but was not quite 100% sure. I will start at the air dryer, I was sure the wire was for the dryer. I have owned my own truck for years but that was also a few years back and the sometimers is kicking in. Thanks guys. | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1349 Registered: 12-2000 Posted From: 76.68.132.136  Rating: N/A |
Purge valve sticking open in the air drier. It isn't returning to the closed position smoothly. Quick and dirty, feed it the spray lube of your choice, longer term, do a rebuild on it. Maybe find the bugs/wasps up inside the exit? happy coaching! buswarrior | ||
| Grant Thiessen (Busshawg)
Registered Member Username: Busshawg Post Number: 43 Registered: 10-2007 Posted From: 206.45.93.160 Rating: N/A |
Thanks for the warning Buswarrior as I am quite allergic to wasps!!! | ||
| Grant Thiessen (Busshawg)
Registered Member Username: Busshawg Post Number: 44 Registered: 10-2007 Posted From: 206.45.93.160 Rating: N/A |
Well guys once again I believe yo were right. I took the bottom cover off of my air dryer. Didn't seem to be any obstructions. I cleaned the cover up , let the dryer blow off a couple of time without the cover which I guess is the purge valve. replaced it and it seems to work fine. Fanned the brakes down a couple of times and it seemed to build properly. I have another question though. After the cover is remover there is a bolt in the bottom centre of the dryer, anyone what this controls? Can I remove it do a more thourough cleaning? I'll do another test run tonight. Thanks for all of your help. | ||
| niles steckbauer (Niles500)
Registered Member Username: Niles500 Post Number: 857 Registered: 11-2004 Posted From: 97.76.134.179 Rating: N/A |
What is the model AD? | ||
| Grant Thiessen (Busshawg)
Registered Member Username: Busshawg Post Number: 45 Registered: 10-2007 Posted From: 206.45.93.160 Rating: N/A |
The model # of the air dryer? I have no idea. All I do know is that it is long a skinny compared to what most highway tractors use. I can take a look tonight after work. | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1352 Registered: 12-2000 Posted From: 76.68.120.236 Rating: N/A |
Hello Grant. There is a desiccant cartridge inside the dryer that is a consumable. You have to change it out periodically for it to be the best at catching the moisture. The bolt will let it all came apart. Sounds like an AD1 or AD2 dryer. They are the originals, after that, they got short and fat. Have no fear, they work just as well, and some old timers say better, than the newer ones. happy coaching! buswarrior | ||
| Kevin Black (Kblackav8or)
Registered Member Username: Kblackav8or Post Number: 97 Registered: 8-2005 Posted From: 207.132.224.131 Rating: N/A |
Might be a good time to replace the air drier with something fairly current like an AD-9. Not all governors are created equal either. |