| Author | Message | ||
| Roger Baughman (Roger)
Registered Member Username: Roger Post Number: 197 Registered: 11-2006 Posted From: 69.232.64.158  Rating: N/A |
The bus has no air pressure, at all. I am going to pull the air line from the compressor tomorrow to see if there is air coming from the compressor. If there is no air, what is the best cheapest way to fix it? Rebuild the compressor or buy one? Rebuilt or used or new? MCI, 8V71 1984. Very much appreciate any advice I can get. | ||
| FloridaCliff (Floridacracker)
Registered Member Username: Floridacracker Post Number: 436 Registered: 7-2004 Posted From: 68.204.16.36 Rating: N/A |
Roger, Make sure and check you air compressor governor. Its possible that its stuck or bad and not calling for air. What are the other symptoms? Had the coach been sitting a long time or just run? etc.... Cliff | ||
| Patrick levenson (Zubzub)
Registered Member Username: Zubzub Post Number: 259 Registered: 5-2007 Posted From: 174.91.223.247  Rating: N/A |
Also if you left a tank drain open, it won't air up. Also if the air reg for the aux tank is stuck you will have air for the mains but the gage won't show it. I have learnt all this the hard way. Oh and BTW tapping on the governor could "fix' the problem, but it means you need to do some maintenance. | ||
| Roger Baughman (Roger)
Registered Member Username: Roger Post Number: 198 Registered: 11-2006 Posted From: 69.232.64.158 Rating: N/A |
I pulled the governor took it apart, It is clean and in good operating condition. The bus has been sitting for some time. I was told to check the check value, but I am not sure where it is or the main tank. I will be looking for it later as I have other things, not bus related, I need to do too. Thnaks for your advice, Roger | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 947 Registered: 8-2006 Posted From: 74.33.38.17 Rating: N/A |
Check the purge valve on the drier if you have a drier | ||
| marvin pack (Gomer)
Registered Member Username: Gomer Post Number: 1000 Registered: 3-2007 Posted From: 71.55.13.161  Rating: N/A |
RRoger, see if you can air the coach up with an auxullary air compressor and that will tell you if you have any issues with the coach first. Then proceed to check the other things mentioned. Gomer | ||
| Roger Baughman (Roger)
Registered Member Username: Roger Post Number: 199 Registered: 11-2006 Posted From: 69.232.64.158 Rating: N/A |
If it airs up with the auxullary compressor does that mean the other conponents except for the engine OEM compressor are working? Thanks for all of the help, Roger | ||
| Dallas Farnworth (Dallas)
Registered Member Username: Dallas Post Number: 96 Registered: 7-2004 Posted From: 75.91.194.64  Rating: N/A |
"If it airs up with the auxullary compressor does that mean the other conponents except for the engine OEM compressor are working? Thanks for all of the help, Roger" Nope, it means that you may have hooked up your shop compressor after the problem and a check valve is keeping the problem from being exposed. The aux compressor needs to be hooked up just after the OEM compressor, usually at the ping tank. Not at the front where the wrecker hooks up to tow MCI's. | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 1221 Registered: 11-2005 Posted From: 209.112.91.180  Rating: N/A |
Start at the compressor outlet to see if there is any output and work forward from there. | ||
| Roger Baughman (Roger)
Registered Member Username: Roger Post Number: 200 Registered: 11-2006 Posted From: 69.232.76.120 Rating: N/A |
I removed the outlet hose from the compressor head and started the engine to find the compressor is working fine as far as I can tell. Next thing I am going to do is remove the outlet hose from the air dryer as that is where the outlet hose goes from the compressor. In that line from the air dryer there is a small vertical cylinder about three feet toward the front. I do not know what this is. It is about 6 inches high and about 2 inches in diamiter. Thanks for all of your help. Roger | ||
| Paul Lawry (Dreamscape)
Registered Member Username: Dreamscape Post Number: 689 Registered: 5-2007 Posted From: 64.40.215.178  Rating: N/A |
Roger, That sounds like the ping tank. If you open the valve at the bottom and get air, check your governor. Otherwise keep moving forward. What model air drier do you have? | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 949 Registered: 8-2006 Posted From: 74.33.38.17 Rating: N/A |
Isn't the air dryer on a MCI up front behind the front axle,check your air intake for the compressor also if a compressor cannot take in air it will not produce air but this problem sounds more like a bad air leak or stuck unloader valves on the compressor.Those little critters love the taste of the dot plastic lines a 1/4 inch line leak will keep your bus from airing up (Message edited by luvrbus on September 28, 2010) | ||
| larry currier (Larryc)
Registered Member Username: Larryc Post Number: 333 Registered: 2-2007 Posted From: 207.200.116.13 Rating: N/A |
Last time this happened to me a loose plug blew out the top of the compressor. I just put it back in. Time before that I had a leak in a air bag that kept the system from pumping up. Air bags rust out in about 7 years. Water lies on the bottom of the bag and rusts the steel out. Rolling lobe air bags will seal a hole one day and leak the next. |