I have never started a thread, but i realize that my few experiences could help some of the people here.
Just to see if Cadillac people appreciate the advice, here it is.
If the crap piece of plastic that is the radiator tank is cracked, you may be able to fix same.
If you have a 1" crack, for example, cut out a 2" x 1" piece of very thin aluminum stock.
The thickness is irrelevent.
Clean the crap out of the crack area with a fine wire brush, then brake cleaner, carburetor cleaner, Tilex, acetone, methyl ethyl ketone, who cares?
Glue the piece of aluminum to the area with a very generous amount of JB Kwick or JB Weld. It doesn't matter which one.
Push down on the aluminum plate hard, then walk away from your car for several hours.
When the plate is secure, drill very tiny holes into the plate and through the crap plastic tank.
Screw slightly larger, yet very small screws, into those holes. leaving the heads of the screw sticking out a few sixteenths of an inch.
Clean the heck out of the entire area again.
Mix up the JB Kwick again, about twice what you think you need, and spread it all over the area.
Do not be stingy. When the JB Weld sets up, the area will be stronger than the original crap plastic.
I have fixed two crap plastic tanks this way. One on a '94 Seville, and the other on a 2002 STS.
I gave the '94 to my son-in-law in 2006, and I still have my 2002 STS.
I repaired my STS in 2008, with about 50,000 miles.
It now shows 108,000 or so on the clock. No leaks. None.
Don't use any epoxies, period.
They will soften and disappoint you something wonderful.
Just to see if Cadillac people appreciate the advice, here it is.
If the crap piece of plastic that is the radiator tank is cracked, you may be able to fix same.
If you have a 1" crack, for example, cut out a 2" x 1" piece of very thin aluminum stock.
The thickness is irrelevent.
Clean the crap out of the crack area with a fine wire brush, then brake cleaner, carburetor cleaner, Tilex, acetone, methyl ethyl ketone, who cares?
Glue the piece of aluminum to the area with a very generous amount of JB Kwick or JB Weld. It doesn't matter which one.
Push down on the aluminum plate hard, then walk away from your car for several hours.
When the plate is secure, drill very tiny holes into the plate and through the crap plastic tank.
Screw slightly larger, yet very small screws, into those holes. leaving the heads of the screw sticking out a few sixteenths of an inch.
Clean the heck out of the entire area again.
Mix up the JB Kwick again, about twice what you think you need, and spread it all over the area.
Do not be stingy. When the JB Weld sets up, the area will be stronger than the original crap plastic.
I have fixed two crap plastic tanks this way. One on a '94 Seville, and the other on a 2002 STS.
I gave the '94 to my son-in-law in 2006, and I still have my 2002 STS.
I repaired my STS in 2008, with about 50,000 miles.
It now shows 108,000 or so on the clock. No leaks. None.
Don't use any epoxies, period.
They will soften and disappoint you something wonderful.