99 Suburban Dad

New here and a new do-it yourselfer. I have a radiator problem and I'm wondering if I need to replace the entire system. The problem seems to be around the metal tube under the main radiator hose on the drivers side. I have some pictures that I have attached. Any help would be greatly appreciated.

myotherchevyisablazer

the part im looking @ in the second pic is your cooler lines for your transmission,there should be 2..they run from your radiator to the tranny to cool it.i would first let it cool down and try and tighten it up...if that doesn't stop the leak which should be small,i would disconnect it let it drain a liitle out and put some sort of teflon tape on it...good lucki would not replace the entire system start with the cooler line and see if it stops the problem,then go from there....good luck

chrisbmo2000

the leak you have is common when you get some age on a cooling system....the big large "nut" looking thing that IS NOT attached directly to your cooler line is where your problem is it holds the actual cooler to the side of the tank. the leak appears to be coolant and not tranny fluid therefore teflon tape will NOT help... undo the big nut with a screw driver (do not pry) it does unscrew and you will see how the seal works....I used some silicon behind the nut and tightened it up on mine....(bad design on GMs part)

992door

so that metal piece with the teeth sticking out unscrews

chrisbmo2000

yep....its called a flange nut.......it works just like a regular nut but I use a screw driver to undo them set the flat blade on one of those "teeth" and tap it with the palm of your hand (if you look close you can see the treads)

99 Suburban Dad

I am monitoring it this week to make sure this is the only place it is leaking and will be working on it this weekend. I also have to change the passenger side interior door handle which shouldn't be a problem as I changed the drivers side a few months ago.

99 Suburban Dad

Well I tried to loosen and tighten the flange nut. Put some teflon tape on it. It started leaking more as the week progressed. Took the main hose off and examined it. Nothing. As I was putting the hose back on I saw a deformation in the radiator between the main hose and the transmission cooling line. Ended up being a crack in the radiator. Replaced it and its running fine now. Thanks for the input everyone.

myotherchevyisablazer

thank you for keeping everyone up to date with the repair and glad you got it all figured out!

chrisbmo2000

Yep thats what happened to mine, but just for clarification those are engine oil cooler lines, tranny lines are on the other side.