79 Expansion Tank Problem

[Big "O"]

Okay, I ordered and replaced the radiator plastic expansion tank for the third time. I am still experiencing a slight bulging around the neck of the tank, I imagine from heat from the anti-freeze. Am I the only one here experiencing this unusual happening. I've had many other vehicles, some that have overheated, and none of the plastic expansion tanks have melted. If anyone knows of a cure for this, please help!!!

 

[page62]

Good to see another '79 online in San Antonio!

Your problem is truly strange! This has got to be a new one for the forum. Here are some questions that might provide some clues:
--Is it a genuine GM tank or an aftermarket unit? (BTW: If you're a TCA member, you can get 25% off parts at Gunn Chevy.)
--What temperature is is your engine running at?
--How full is the coolant level in the expansion tank?

 

[Big "O"]

We need to get together and figure this one out. The tanks were ordered from Ecklers and Zip. I am always constantly now checking the tank for coolant level regularly and also for signs of damage. I noticed the bulge happening again at the same place. My temp rarely exceeds 210-220. I usually drive it on the highway from O'Connor and 1604 to UTSA (on good sunny days). I have even replaced the radiator cap to a 13lb to relieve the pressure.
--By the way, how do I join TCA so I can get discounts?

 

[page62]

You're lucky! Gunn is practically around the corner from you. Your operating temp is okay, so you must be suffering from inferior-quality tanks. Try a genuine GM unit.

Check out the website at www.texas-corvette-association.org Although the club is top-heavy with C5 owners, there's a large group of people who don't care what you own -- they just wanna have fun! Weather permitting, we're making a run to Shiner tomorrow (yes, Monday!)

Feel free to drop me an email, it's in my profile.