Saltshaker,
I believe it will. On the bottle it claims to seal the largest leaks that other leak sealers won't. Here is a link to the product and a clear description.
http://www.autozone.com/autozone/acc...er=560508_0_0_
This is what I used. It permanently repairs leaks in gaskets, head gaskets, radiators, heater cores, intake manifolds, blocks, heads and freeze plugs. Plus you can leave it in the cooling system. No draining and refilling.
I removed some
antifreeze to make room for the additive. In your case I would add 1/4 of the Bar's Leak into your expansion tank. I would empty the remainder of the Bar's Leak into the radiator. Don't forget to top off your coolant level after the Bar's leak is added.
Then start the vehicle and let it idle for 5 minutes. After that I drove mine for about 20 + minutes.
good luck