BAC Forum
General Boards => Technical Support => Topic started by: Jeremy Parrett on December 22, 2013, 03:48:46 AM
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Gerald,
after 38,000 miles since 2010 I am now on the 3rd Ford plastic tank and it is now leaking.
Is there a steel/metal tank we can replace the cheap plastic ($158) lol.....with ??
Maybe a Freightliner or Cummins part ?? Thanks, Jeremy
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Jeremy,
There are a number of inputs re metal expansion tanks if you do a search on "expansion tanks". BCS has one but they really love it as they want ~$400 for it.
Steve
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Jeremy
The one from BCS is pricey but worth it when you get one. It doesnt come with a plug for the drain hole but it is available at most hardware stores for about $2. I think it was a 3/16 plug.
Keith
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Steve and Keith,
Thanks for the info. I guess 3 x $125 Ford tanks comes close to the BCS price !!
Jeremy
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That's right, Jeremy, and when we needed one this last summer we couldn't find a single Ford tank in the whole country! Were told by everyone that we called that they were no longer making this tank. Ours was leaking so bad that we couldn't leave the RV park to take it home. BCS overnighted the metal tank to us and we installed it ourselves the next day! Awesome service and we won't have to deal with this annoying problem ever again!
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FYI A call to BCS 3 days ago and a new metal surge/expansion tank is on the way to me here in Florida. Thanks for all the help.
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The article in this month's FMCA magazine about the new 2015 Monaco Dynasty from ASV mentions that it comes with a steel expansion tank. They're learning.
Stan
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FYI.....BCS shipped me a new black powder coated steel expansion tank. It is much heavier than the Ford plastic tank. Checking the steel angle mounts I found they were attached to the wood undersill above the engine bay door with drywall screws.One screw had let go. I replaced these 4 screws with SS lag bolts to be safe. The new tank sits right on these original brackets. I used new SS bolts ,nuts and lock washes to secure it.
One thing.....the 2 small bleeder hoses have an ID that is smaller than the hose barbs on the new tank. Some soap and a bit of effort solved this issue. The main coolant hose fits perfectly.
Having a sight glass is a real bonus. The drain hole plug form the Ford tank fit the BCS tank .
Pics to follow.
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Jeremy, I know the new tank will work well Ty at BCS heard of the problems and designed the new tanks to last
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Ran her up to operating temperature and no leaks. BCS Tank is a huge improvement over the Ford product. Will be at Southern Comfort Rally. Hilton Head Island if anyone would like to see the new tank.
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Here are pics of the BCS expansion tank installed in my 2000 Beaver Marquis Amethyst. If you are considering doing this conversion or not I would strongly recommend replacing the drywall screws that secure..lol....the tank brackets to the engine compartment roof,with decent sized lag bolts.
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Jeremy,
I just ordered a replacement steel tank from Indiana Heat Transfer. I have not received it yet. Their price is about $175. Bill Harris is the engineer there and is very knowledgeable. I had to have them locate the filler pipe on an end since the engine door closes so close to the tank. Their standard location is at the rear of the tank (which would hit the door).
Richard & Judie Crane
2000 Marquis C 12
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Richard.
It will be interesting to compare tanks. I cannot fault my BCS tank but you definitely have a great price . The BCS tank is exceptionally heavy duty. Very thick plate. Welding is awesome. Price.........we'll it is the last tank I will ever buy...lol !
Jeremy
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Quick question:
Where are you finding the leaks?
Has anyone tried plastic weld on the older ones?
Tom
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Tom,
both my previous plastic tanks leaked on seam/welds. Side seam on first and the cap tube seam second time. The pressure is the issue 18 psi
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Tom,
Jeremy is right about the Ford designed tank failures. Plastic welding will not work because the tank design is not strong enough to withstand the 13 to 15 PSI cooling system pressure that they are operating under. The last one that I had fail had at least 6 cracks in it before it split wide open and started dumping coolant. The only way that I have found to make the Ford coolant surge tanks last is to lower the radiator pressure cap to a 7 PSI cap. I did this 3 or 4 years ago and I have not had a tank failure since, and before that I was buying a tank about every 2 years.
Gerald
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Gerald,
there is a relationship between pressure and temperature. Something to do with raising the boiling point maybe?
I wonder if lowering the cap pressure could affect the way the system is supposed to work?
Maybe another member here can add his 10c worth !! Jeremy
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Yes... increasing the pressure on a liquid will raise its boiling point. Conversely, that is why cooking times are longer at altitudes... because the liquids will boil at lower temperatures - that is, not get as hot before they boil - and cool themselves through evaporation. Liquids have to absorb heat to evaporate. That's why we perspire... to cool ourselves through the evaporation of the perspiration. The evaporating perspiration absorbs and carries away heat.
Lowering the cap pressure will effectively lower the boiling point of the coolant.
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A 50/50 mix of coolant will boil at 223 degrees F at normal atmospheric pressure. At 15lbs of pressure the same mixture will boil at 257 degrees F. The relationship is about 2.25 degree rise of the boiling point per pound of pressure. A 7lb cap would provide a boiling point of approx. 239 degrees F.
I also run a 7lb cap and have not had an issue with the expansion tank (yet) and mine looks like the original which would make it 12 years old. I think the highest coolant temp I have seen when driving was 204 degrees so I am not worried about a boiling point of 239 degrees. Given the parts involved, the hoses, the overflow tank, the radiator, the transmission cooler, and the gaskets I think the lower pressure would stress these parts less as Gerald's observation regarding tank life seems to indicate. When you run the system full there is no room for expansion without forcing the 15lb or 7lb cap relief valve up, in my case that goes to a second overflow tank and gets drawn back in when cooling takes place. If your coach runs hotter on climbs then the extra margin may be worthwhile but these coaches seem to be quite well cooled.
I also run a 7lb cap on my Aqua Hot to stress that system less and hopefully not induce so many leak points.
Later Ed
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Ed:
Excellent information. Although I have ordered the new expansion tank, I will use your approach on my AquaHot and go to a 7lb cap.
Thanks: Larry D.
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Interesting thing happened ...the new expansion tank sight glass cracked......it is not glass but plastic. I removed it and installed a brass blank,as well as a Caterpillar overflow tank.
Pics to follow.
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The new Caterpillar overflow tank catches the coolant that might otherwise escape after lowering the expansion tank cap pressure to 7 lbs.
Since this picture was taken I have removed the cracked plastic sight glass and installed a brass blank in the opening. The Caterpillar overflow tank makes checking coolant level easy and topping up a breeze.
I had to relocate the washer bottle for the backup cam.
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Nice job and you probably have saved some future headaches with the 7lb cap. I also added the extra overflow tank after Gerald passed that tip along.
Later Ed
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Thanks Ed. It seemed a logical final step to solve this problem. Now I have to fix the wandering tachometer !!
Jeremy