Broken on I-70

FolkBus · September 17, 2015, 11:07:51 AM

Hi all

Headed east on I70 dropping down out of the Eisenhower tunnel I look down and my air pressure says 30lbs and dropping. found a wide spot quick and thank heavens for spring brakes. I took a walk around the bus and can't hear any air leaks and no bad sounds from the air compressor. I replaced the governor on the compressor about a 1.5 years ago and has been working fine.

Ideas???

Sitting on I-70

--Mike

luvrbus · September 17, 2015, 01:32:22 PM

1st step is find out if the compressor is turning you can tell that by listening to the intake be it a filter or hose,no intake no compressed air for sure

skihor · September 17, 2015, 03:36:46 PM

Quote from: FolkBus on September 17, 2015, 11:07:51 AM
Hi all

Headed east on I70 dropping down out of the Eisenhower tunnel I look down and my air pressure says 30lbs and dropping. found a wide spot quick and thank heavens for spring brakes. I took a walk around the bus and can't hear any air leaks and no bad sounds from the air compressor. I replaced the governor on the compressor about a 1.5 years ago and has been working fine.

Ideas???

Sitting on I-70

--Mike

Hi Mike, I'm about 45 minutes away. What can I do to help ? I have tools, not a lot of knowlege but have been around. Give me a call anyway. 303-513-nine042

FolkBus · September 17, 2015, 04:23:36 PM

Hi all

Here is an update. I seem to have a leak near one of the valves (or is a valve) at the rear axle (MC5A). I went and picked up a small compressor so I could put air on the system (teach me to leave the small one at home) I can hear air leaking but can't find the source. If I try to listen for it with the motor running to much noise, so I'm still not completely sure about the compressor, although right now I'm not thinking it is the problem.

The air ride is staying up so I don't think it is leveling valves.

More ideas???

Thanks

--Mike

FolkBus · September 17, 2015, 06:31:24 PM

Another question...could the inversion valve develop a leak? Enough of one as to not let the system air up? I tried to pressurize the system from both front and rear external ports and I just get the same leak noise from the same place. I have a 3 gal. tank on my small compressor and it will empty in less then a minute.

--Mike

John316 · September 17, 2015, 08:16:03 PM

Mike,

Here's my guess, because this happened to us. Short story - check the unloaders on top of your air compressor.

If you cannot hear an air leak, and you don't have air, that tells me your compressor isn't running. If it is, you should hear air leaking. That being said, I wouldn't waste time with your little compressor trying to find/fix a leak. I would investigate your compressor.

I had to take the top cover off of our compressor, and manually work the unloaders. Basically, they were stuck in the "unloaded" position. After I manually worked them, they were stuck in the "loaded" position, and the air dryer would purge every minute or so. Didn't hurt anything, and we had air.

Make sense?

Best of luck!

John

eagle19952 · September 17, 2015, 08:50:18 PM

Mike, are you saying that your portable compressor is not able to charge the complete bus air system and all of it's tanks. ? I would certainly do that and check for leaks

or are you saying that the engine compressor is not able to charge the bus air system.?

FolkBus · September 18, 2015, 05:37:38 AM

Both

eagle19952 · September 18, 2015, 08:29:28 AM

Quote from: FolkBus on September 18, 2015, 05:37:38 AM
Both

THEN IT WOULD SEEM TO ME THAT THERE IS A MASSIVE LEAK SOMEWHERE

AND NO i am not shouting, i am to lazy to retype this...

gumpy · September 18, 2015, 05:23:49 PM

You may have cracked a brake hose.

BTW, since when do MC5s have spring brakes? Did you replace the DD3s?

FolkBus · September 18, 2015, 05:35:13 PM

A little more research and yes I do have DD3s. Yes I do have a massive leak and I do believe it is a split/cracked line. I had to work in Denver today. Thank heavens I got way off the highway and the CSP is ok with me being here while I finish my work in town (today and tomorrow) then repairs begin.

Thanks to all for the help so far

--Mike

luvrbus · September 18, 2015, 06:16:03 PM

The air bags and air beam are in the way for normal spring brakes on a MCI 5 but if you can find a set of the Maxi spring brakes they will fit that is what I installed on my 5, back then they were easy to find at Mack Truck or the outfit in Texas that manufactured the Maxi's.
I didn't think he had springs but you never know

Dave5Cs · September 18, 2015, 06:54:26 PM

Mike I still think it is a diaphragm in one of the rear wheels is blown. Just saying.

FolkBus · September 18, 2015, 07:02:15 PM

Hi Dave,

Posted an answer to some of your posts on the other board. Question if I have a blown diaphragm would that keep the system from airing up even a little?? Because however I try to get any pressure in the system I can't even get the gauge to twitch.

--Mike

gumpy · September 19, 2015, 01:50:11 PM

It's been awhile since I worked on my DD3s, but if I'm not mistaken (and someone will correct me if I am), the parking brake requires pressure on the lock port
to keep the rollers from contacting the shaft while in normal operation. There's a line from the inversion valve to the lock port on the chamber. I'm not sure what
the pressure is on this line, but probably 85 or above. It's possible if this line were cracked, it might be enough to keep a tired compressor from airing up the coach.