Other than replacing the radiator, which is the best option, I have used the JB weld stick. It is any epoxy putty. Just knead it into a long cylinder, then place it into the crack. Work the putty into the crack very well. Do this when the radiator is cool, for best results. Max heat temp for this product is 300 F. So dont let it overheat. JB Weld stick costs around $5. Good Luck
Not sure if this will help but I have recently discovered that many plastics can be "Welded" using simple PVC pipe solvent.
the plastic radiator and expansion tank
On the lower driver side of the radiator!
Pontiac Trans Sport was created in 1990.
Look on bottom or rear of radiator
Weight on my Pontiac LeMans Sport registration is 3800
TAke it to a garage and have someone look at it. The cooler for the trans may have ruptured and is leaking fluid in the rad and coolant in the trans.
This is no question.....
It's concealed in the roof
Remove bottom hose
I would say a healthy weight would be about 110 lbs to 120 lbs
Wiring for 91 Pontiac Transport: http://www.auto-olds.ru/PONTIAC%20TRANS%20SPORT%201991.pdf