Can't maintain air pressure.

[Van]

Bob, if you come back the same way, stop on by. There is also the House of hose in Henderson if ya feel you might need to grab a replacement hose

   Van

[bcaddel]

Hi Van, I have been meaning to give you a shout since we arrived in Vegas, but just haven't taken the time. I just might be needing a few items at the house of hose.

Larry, I left you a voice mail but things have changed a little since I left Albuquerque. Let me know if you have any thoughts about the heating up idea.

Just as we left Santa Rosa, we lost our air pressure again. We pulled off the side of the road and within about 5 minutes the compressor started working and building air. It has started working again each of the three times it quit over the last couple of days within about 5 minutes of pulling over. I as still thinking it may be due to heat.

I understand the compressor is cooled by the engine coolant, and we have had several times when we have went over 200 degrees yesterday and again today and close to the 210 mark on occasion. The engine temp had heated up close to the 210 degrees just a few minutes before we lost the compressor this time and possible the previous 2 times. I usually just down shift and raise the RPM up around 2300 and it cools down the engine temp. On occasions we have had to turn the misters on but that is fairly seldom.

I am trying to get it to heat up now and if I can get it over the 200 degrees I am going to keep bleeding down the air and hopefully the compressor will stop providing air and I plan to turn the misters on and it will cool down immediately and hopefully that will allow the compressor to start providing air right away. If not I will pull over get out the soapy water and flashlight and see if I can find any more air leaks.


Once again any comments or suggestions are appreciated.

Bob

[Flatspot]

Bob,
Well I guess that I should have taken a ride along in the engine compartment. When you come by here on your way back to Nevada I'll slip an unloader kit in the compressor then we will take it for a drive to see what happens.
I also recognized Cozy. Rest assured that I pay more attention to buses and women than all you hairy legged guy's.
The bus was loosing air immediately after it unloaded when you pulled in here, that isn't what we observed after we did the work on it so I am kind of thinking that the unloader might be hanging up when it gets hot.
Also, observe the air pressure after you shut down and let me know how long it takes for the air to bleed down like is it at 0 in the morning?
I also want to look to see if there is a shutter control anywhere in the cooling system. I didn't see one but I wasn't specifically looking for one. I don't know if your MCI model would have had one. Maybe others can chime in. If there is a control it might be opening up when the engine temp gets up there and dumping air faster than the air compressor can keep up. I don't want to over think this.
Plan on stopping by on the return trip and I think that you have enough confidence now that you can make it back here OK.

Happy Trails,

Larry

[Busted Knuckle]

I sent Jack a PM asking what turned out to be the problem with Vivian's bus back after Bussin 2010.

Hey Jack,
Do you recall what the problem was with Vivian's bus when she had air problems after the rally & you, Tom & I went and got her back to your place?

Looks like Bod Caddel has the same or similar bus/problem.
http://www.busconversions.com/bbs/index.php?topic=21302.0

 BK  

Boy, I have slept several times since then, but I think we ended up replacing the poppett valves in the compressor.  Jack

[Flatspot]

BK and Jack
Thanks for the lead. I'm going to look the compressor over real good when he swings back by here next month. Haven't heard a word so I suspect that means the bus and occupants made it to their destination.
I've got compressor valves and an unloader kit on the shelf.

Happy Trails

Larry

[luvrbus]

Jones do have a discharge valve kit on the shelf check that before replacing the unloader valves you can check the discharge valve with air but you remove the head to replace it, replacing the unloaders will help but it won't last long with a bad discharge valve

good luck

[muldoonman]

Bob just curious, how many miles do you have on your bus?

Glen

[bcaddel]

My dad had the engine replaced in 1999 by Stewart Stevenson Power inc in Commerce City Colorado. We have put 31,000 miles on it since. My parents had engine, transmission, power steering, radiators all replaced in 1999 and put about 8,000 miles on it from 1999 to 2003 and it set parked from 2003 to 2007 when the wife and I purchased it from them  and we have put 23,000 miles on it from 2007 until today. Everything seems to be strong with the exception of it runs hot but that is more our fault as we have done stop and petal to the medal with not much in between. Since talking to Larry, we have kept it around 2000 rpm and 55 mph in 4th gear (5 speed trans) and it has stayed under 190 degrees but the country has been fairly flat. We will be headed back into the hills in a few days and I am curious to see how the temperature holds up (or down).

We have only had 1 instance of not building up air pressure since we have backed of the rpm's and kept the engine temp down. It was running around 185 degrees the other night and air pressure went down to about 80 so we pulled over and I hooked up the portable air compressor and pumped the pressure back up over 110 and the engine compressor started working like normal. This is what we did each of the 5 times the air pressure has dropped. I thought it started working because the engine cooled down but it wasn't hot this time so it may be by pumping up the pressure it is releasing what ever might be causing the pressure to drop.


As you  can tell, I just don't have the knowledge to tell what might be causing the problem but it sounds like several people here have a pretty good feel for some  possibilities. We plan to stop by Larry's next Thursday and see what ideas he has. In answer to your question Larry, it bleeds down completely to 0 in about 4 hours after shutting down.

Thanks everyone for the ideas and comments. It has been a real enjoyable trip even with the air pressure issues and hopefully we will be able to find a fix for that.

Bob

[Flatspot]

Clifford,
I've checked and I have a discharge valve kit as well as an unloader kit. I've also got gaskets. The B/W house I use stocks a lot of parts and they will be my fall back. Thanks for the direction. I'll not do the unloader with out doing the discharge valves

Bob,
I'll expect you a week from tomorrow, 9/8. I'll PM you and you can update me on an ETA. We need to look for a few more air leaks, in my mind, time permitting.

Happy Trails,
Larry

[Scott & Heather]

Wow...I've been reading through these posts...and can I just stop by to say how I am constantly amazed and impressed with how helpful you guys are to one another...it's like having the "A-Team" at your disposal all over the U.S.  Someday, when I grow up, I'll be able to help someone with a real problem. Until then, I could wash your windshield....I'm 6 foot and can reach. 

[bcaddel]

Larry, that sounds great, we are planning on leaving Texas Monday sometime and finding a nice quite spot between your place and here to kick back and relax for a couple of days before heading to Vegas on Friday.

Anytime from Tuesday to Thursday works for us so just tell me a time and a place and we will be there ready to follow your lead. Thursday morning in that same spot is what I am planning for but if a there is a better time for you that wouldn't be any problem for us.

Just like Scotty said it sure is great having the "A-Team" help us out like this.

Bob

[luvrbus]

Bob,going to Vegas you will probably take 93 from Kingman if you have trouble in that area just call and I'll come help made a trip over there today for the doctor.
Don't leave Jone's place without a blue cheese stuff burger he does a pretty good job on those lol 

good luck

[bcaddel]

Hey Clifford, If Larry has time we would love to try one of those Blue Cheese Stuff Burgers you mention. From watching him dive into the engine compartment last week when we were there, I would say that BLUE cheese might have been yellow cheese before all the grease from his elbows got onto it. But he has some almost magic hand cleaner that he let me use last week, so I feel pretty confidant that the Blue Cheese Stuff is probably really  Blue Cheese. (just kidding Larry)

I would love to put a face to the "luvrbus" that I have been reading for these several years so I almost hope something (minor) does go wrong if it gives me a chance to meet ya. If we and you have the time we would really like to hook up with you as we come through your neck of the woods. If it doesn't happen this time then hopefully next time. Thanks for your suggestions on this issue and several more in the past that have been quite helpful.

I cant hardly imagine anyone being more knowledgeable and helpful than Larry but I know there are several on these boards and bus nut newbies like myself are very lucky to have access to you guys and your experience. Thanks to you all for sharing that knowledge and experience.

Bob & Pearl

[bcaddel]

Larry , I was reviewing the paperwork from Stewart Stevenson Power when they installed the rebuilt engine in 1999 (31,000 miles ago) and I see that they installed a new air compressor at that time. I don't know if that includes "the unloader or discharge valves" or not but just thought I should mention it. Lots of years ago but not many miles.

[artvonne]

Wow...I've been reading through these posts...and can I just stop by to say how I am constantly amazed and impressed with how helpful you guys are to one another...it's like having the "A-Team" at your disposal all over the U.S. 

  Yeah Scotty, im always amazed too. I too hope I can one day help someone out, maybe thats part of the charm?

  I remember back in 1988 when we were wreckin Buses, I had a copy of a BCM or FMC magazine, there was a whole fleet of Bus conversions went up to Alaska. I remember then, reading how they all pitched in to help each other with different problems and thought that was pretty cool. But I never expected anything like what we see here.

  When I get my place more hospitable and under control, im thinking of building a pit and having good power available. Maybe someone could stop by for a beer someday.