New Surge Tank

[Steve Huber Co-Admin]

The coach came equipped with the OEM plastic / (lexan?) surge tank. Good news was that it appeared thicker and thus less likely to crack, compared to the tank on the C12. Bad news was that the wall thickness (or discoloration from age) made it very difficult to see the amount of coolant in the tank. No problem; I added an expansion tank. Then I started noticing coolant seepage coming from the neck of the tank. The hose to the expansion tank must be leaking. Nope. The leak was a hairline crack where the neck joined the body of the tank. Spoke to the shop that does my heavy maintenance and they noted that they have seen this on a number of coaches. Called BCS and Matt confirmed this. They have a metal tank available to replace the plastic OEM unit for an added $75. I removed the OEM and installed the metal one this AM. Interestingly I found I also had seepage at the 2 return lines on the rear of the OEM tank. Had I not added the expansion tank, the plastic OEM unit would not have been full very often and the seepage probably would have been minimal. But with the expansion tank, the OEM tank is full most of the time so any leak is obvious.
Steve

[Edward Buker]

Steve,

Nice job. Seems like plastic tanks are a problem in many coolant situations. My Mini Cooper has a plastic tank that is prone to fail also...good choice on the metal tank :-)

Later Ed

[Larry Williams]

Steve, I have the exact same tank on my coach. It has multiple stress cracks that are leaking at the bottom front of the tank. I am out on a trip now and am having overheating problems because of loss of coolant. I will have the tank replaced when I get home. What are those two line connections  at the top for?

I have tried to temporarily repair the cracks with epoxy to no avail as I think the tank is polyethylene or polypropylene and epoxy does not work on those. I have had some minor success using a plastic welder, but it still leaks. I am trying to limp home.

I might try to call BCS today to see if they have a replacement tank and have time to install it as they are on the way home between California and Washington.

Edit: As I suspected, they are booked into October.

[Steve Huber Co-Admin]

Larry,
The 2 lines at the top are return lines but I didn’t trace them to see where they originated. Replacing the tank is a pretty straight forward job. Drain the coolant level down to where it is below the bottom of the tank, (about 5 gallons or so). Then remove the hoses and electrical connection to the tank. You’ll probably have to cut the 2 return lines to get them off as the tank fittings are barbed. Since these lines were cut to length, you may need to add a length of hose to reattach them. It takes a 3/8” ID hose splice. I had to lengthen one of the lines. Use Blue thread locker when installing the brass fittings into the new tank. Be sure to tell BCS to include 2 brass plugs as the tank comes with 4 ports, 2 of which need to be plugged. Any shop in should be able to do the job. Maybe you could call BCS and pick up the tank there and take it to another ship in town for installation. Just a thought.
Steve

[Will Hansen]

Thanks for the heads up Steve.  I have the plastic tank, as we both would have expected.  Mine seems in better shape than yours so for now I'll add the task of replacing it to my ( never shrinking) to-do list.  Of course it does look sort of 'crispy' so I'll need to monitor it.
-Will

[Chuck Jackson]

Northwest RV Supply has them also.

http://www.nwrvsupply.com/product/BU01806583ST.html