I have a 98 silverado and i need to replace the radiator.... does anybody know what all the lines and hoses that stem off the radiator are used for... I know the upper and lower hoses, but there are 4 little lines (2 on each side) coming off the back of the radiator... what are these used for??? tranny cooling lines???

 

the ones on the passenger side are the radiator cooler the ones on the drivers side are the oil cooler or maybe the power steering but I think the power steering cooler came on later models so it is probably the oil cooler.
You can trace the lines back to each source