Expansion Tank Bleeder Valve

[samg1965]

A couple of years ago I replaced my coolant expansion tank with an after market. two years later I started losing coolant again it and a mechanic diagnosed it at the ventilation bleeder valve. The tank is no longer under warranty and I can take an inexpensive way out by replacing the bleeder valve instead of the entire tank. 1)Does anybody have experience with this? Seems easy enough, but is it really? 2)Could I have something else going on in my cooling system that might have caused the bleeder to fail (other than a poor quality replacement)?