BAC Forum
General Boards => Technical Support => Topic started by: Terry Melot on August 26, 2014, 03:11:17 AM
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Traded for a 2005 Pat Thunder about a month ago. After a service job a Bend RV Service, travel to Newport and being parked for two days at Pac Shores, started the engine to move the coach a few inches. Had to jump house batts to start. Moved and shut down. Check date on chasis batts, 2008. Time to replace. Removed this morning and traded for new ones at Napa. Installed batts and started engine to check batts. Noticed both air needles at zero. Coach always held pressure for days before. Air pressure did not come up. Called BCS, spoke with Ken Carpenter. He said the batteries cannot affect the air system. He Asked where the air was going when the engine was running. Went outside and investigated. Serious air blowing sound coming from generator area in nose. Crawled under, could hear it loudly but cannot locate. Any suggestions? What could possibly be dumping all the air the compressor makes. Needles barely move, never getting to the first mark on the pressure gage.
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Terry,
If it is in the dash area, it is probably the air line to the air brakes. You are going to have to locate it and repair the leak to move the coach.
Gerald
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If it is up front underneath are the air tanks in that location? Sometimes a small extension lighted mirror can help low where you cannot go.
later Ed
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The air tanks are on the side just behind the LP tank. Easy to get to. No leaks around them. The leak is in the generator cavity. Gerald is probably right, it is the line to the air brakes. Just don't know how to access it.
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Could the air dump valve be stuck open?
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The air tanks are on the side just behind the LP tank. Easy to get to. No leaks around them. The leak is in the generator cavity. Gerald is probably right, it is the line to the air brakes. Just don't know how to access it.
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Could the air dump valve be stuck open?
Richard, that was my hope. When it first happened, I hit the air dump switch. There was stil some air left in the leveling system that promptly bled off.
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On ours the 4 tank bleeder ports and auxilliary quick connect port are curbside rear. But I understand that most rigs have them up front, accessible by opening the genset slide, so tow trucks can easily connect their air lines to keep the coach brakes off during tow. I'd check that one of those bleeder ports isn't open for some reason, or a line damaged or popped off, and ditto for any quick connect that may be jammed open by debris.
More than likely Gerald is right.
Joel
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Found the bad leak. The 1/4" tube going to the air pressure gage rubbed a hole where passing thru the frame. Pulled a new tube along the same route and coupled it in. Leak fixed.
Whoops. Air still bleading down. Now we can hear a second leak. Same area but cannot isolate it. The coach can be driven. This leak is slower than the compressor make up air. I've exhausted all ideas. Will let a professional try to isolate it.
Thanks so much for all suggestions. Bill Sprague was a great help in fixing the bad leak. Thanks so much, Bill. I owe you one.
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Terry, how long you going to be there? Suzie and I will be back late Thursday afternoon. As you know I am quite small and can fit under your coach and help find/repair your leak.
Marty
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Terry, how long you going to be there? Suzie and I will be back late Thursday afternoon. As you know I am quite small and can fit under your coach and help find/repair your leak.
Marty
Marty, I'll be here till next Monday afternoon. We have an appointment at Kaiser Brake and Alignment in Eugene, early Tuesday morning. Thanks for the offer. If you have any suggestions how to find the leak, I am open.
I have been under the coach where the two air tanks are. There are numerous lines that leave that area and go into the frame. There are more lines that join that big bundle going thru the frame. Somewhere in that bundle within inches of where it comes out in the generator area, there is a leak. I now believe I caused the two leaks by putting a small wire that should have been a ground onto a hot terminal when I changed the chassis batteries. The leak that Bill and I located and pulled out looks like the hole was melted into it and not chaffed. It just dawned on me, there may be more than one leak still in there at the hot spot. I searched as if it was one leak and never got the noise to stop. There may be two or more still leaking. I need more vice-grips to pinch off more than one line at a time.
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Terry,
There is an inexpensive mechanics stethoscope that you can get at Napa. I think the kit has a long and short metal tip/tube. If you can hear the leak normally I think it may be quite possible to isolate the location to a very small section of tube bundle. You could open an air tank drain enough to have a similar noise/leak and get a little practice with the stethoscope at the valve to see how well it works.
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Stethoscope-Mechanics/_/R-SER835_0006403480
Later Ed
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Terry
DeWaine had an air leak last year and he went to Source Engineering after talking to them at 7 Feathers. They are located in Coburg, just north of Eugene 5 miles. They found and fixed his air leak in 45 minutes. .
Sorry we missed you at Pacific Shores.
Chuck
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Terry
DeWaine had an air leak last year and he went to Source Engineering after talking to them at 7 Feathers. They are located in Coburg, just north of Eugene 5 miles. They found and fixed his air leak in 45 minutes. .
Sorry we missed you at Pacific Shores.
Chuck
Hi Chuck, also sorry we missed you and Karen at Pac Shores. If Kaiser Brake in Eugene can't fix the leak, we'll try Source Eng. Thanks for the info. Marty and I have found the leak. We know exactly where it is with a few inches. Problem is, it is back in the frame and we cannot identify which line it is. We know it is not coming from the tank area. We pinched off everything from that area.
Thanks to everyone for all the suggestions. Will let you know when it is fixed.
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Terry
I believe I would be looking for a different root cause. Doesnt seem right that a small wire hooked up wrong can provide enough power to the frame to melt plastic lines. Wouldnt the line itself overheat first?
Also, if you located the second leak within a bundle. Wouldnt the leak have to be on the outer part of the bundle where it is touching metal?
FYI we were at Kaiser just before BCS. They are good people.
If you use a GPS to get to Kaiser be cautious. Ours took us through small residential streets to Taylor street.
One street was posted "not a through street" and all the parked cars made it very tight. The better way is to stay on Chambers to Second street and then Taylor.
Just a heads up!
Good luck
Keith
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Keith,
Terry said that he mistakenly hooked a ground wire to the battery positive terminal. In such cases, the wire can turn red hot almost instantly, and burn or melt anything that touches it. If the wire ran through the bundle that he is referring to, it could have melted the air line in the center of the bundle.
Gerald
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Gerald, you were right. Bill Sprague and I found the bad leak and replaced the 1/4" tube where it ran thru the frame/bundle. A melted spot about an inch long, no doubt from a hot wire.
Marty and I looked and found the second, not so bad leak, in the same bundle but could not isolate it.
Marty, it was the 1/2" red line running to the air tank. Very small "melted" hole in it. Either we never had it pinched off completely or the line took a long time to bleed all the air off and we never waiting long enough.
Took the coach to Kaiser Brake. After they looked for an hour or so they said they would need to remove the fuel tank to isolate it. I said no thanks and picked it up.
We went to Bend where Jim Sizemore (RV Outfitters) installed a new induction cook top and removed the LP tank. Then took the coach next door to Bend RV Repair and Jeff had the leak located in 30 minutes. Another hour and a half and we were out of there on the way to Newport. We knew we'd be in after 10:pm and thought the guard would not let us in that late. A call to Vicky Warren and she informed us that "owners" can get in until the guard leaves at midnight. We pulled in at 11:30. The stars were out and it was a beautiful night.
Thanks Bill and Marty for all the help. Thanks Vicky for getting us in late. Thanks everyone else for the suggestions. This forum has been really helpful to me on many occasions, I really appreciate it. Glad to have our Beaver road-worthy again.
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Hi Mike, I sure could've used your help changing the chassis batteries. Made the mistake of not taking a picture of the cables. I caused all my air leak problems.
We are changing coaches. Pick up our Marquis later this month. We have our Thunder on the market. The previous owner of the marquis installed a K&N air filter on the Marquis. I guess everyone is always trying to get more air to their engines. I'm getting 51 psi on the turbo gage, 1750 rpm, 4th gear, going up a long hill.
I'm not sure the engine is made for more. I know in hot weather it doesn't have the cooling capacity to put out that much horsepower for very long. More HP wouldn't do me any good if the engine won't stay cool.
Happy travels.
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...... it was the 1/2" red line running to the air tank. Very small "melted" hole in it. Either we never had it pinched off completely or the line took a long time to bleed all the air off and we never waiting long enough.
..... Then took the coach next door to Bend RV Repair and Jeff had the leak located in 30 minutes. Another hour and a half and we were out of there on the way to Newport.
........Glad to have our Beaver road-worthy again.
Thanks for posting the end of the story. Did Jeff show or explain how he identified which of the several lines it was?
The Beaver related resources in Bend never cease to surprise me!
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Terry,
I have been an advocate of Donaldson Endurance Filters. The technology they use is to place some Nanofibers above the traditional filterface to capture contaminants above the filter so to speak, so that the capacity to handle particle load over time is significantly increased without decreasing air flow. Beyond that they have about the best filter particle capture rate of all particle sizes on the market today. This filter design makes sense to me and the design was born out of a need to better handle filtration in military applications in the extremely dusty environment found in the desert battle fields. I do cringe when I end up in one of the really dusty roads and a huge cloud of dust is all I can see in the mirror :-) One of the worst in our travels was the access road to the Borax mine visitor center in Boron CA......looked like a dust storm all around the RV when we pulled in there.
http://www.donaldson.com/en/engine/support/datalibrary/000165.pdf
This is a good test report that compares K+N filters comparing them to other available filters. The net of the results is that K+N filters do a very poor job of keeping dirt out of your engine when compared to other filters. With the expense of these engines I would never go there. If you have a restrictive air box filter design issue which I believe some of the Beaver coaches had (not sure on yours), changing that system and using excellent filters would be my first choice. Not sure what the reasoning was behind that change to K+N on your upcoming Marquis. K+N has excellent marketing and maybe that is how this coach ended up with a K+N filter.
http://www.nicoclub.com/archives/kn-vs-oem-filter.html
K+N filtration has their fans and I am just sharing my personal choice based on the test data that is available. Your choices may be different...
Later Ed