I have a 2003 Blazer with about 84,000 miles on it. I went for a rountine oil change today and while the vehicle was waiting, I notice it was dripping liquid at the front and I wasn't running A/C. I determined it to be coolant and looked where it was coming from when I got home and also notice there a little puddle of coolant on the garage floor that was there before I left this morning. I saw on the upper side of the radiator on the driver side there was coolant, coming off those side ribs. It appeared to draining from the front of raditator, which is hidden from my view. My reservoir tank is still ful of coolant. My question is should consider putting some stop leak stuff, replace the radiator, or just let it go for now?

 

Don't use the rad sealent, it'll just muck up the rest of the system & heater core. Check out where it's coming from & if it's from the rad & not a loose cap or hose clamp I'd replace the rad. They aren't that much $ & it's always a good time to back flush the system to avoid issues down the line.

 

First & foremost do a pressure test! This will eliminate just swapping parts-as rottidog said:NO RAD SEALANT!!!

 

I just had this problem on my 2000 Blazer last weekend. After I shut the truck off it would leak enough to make a puddle then stop.

Once I took out the stock air box to get a better look at it I hooked up a pressure tester too the radiator and as soon as I put pressure on the system it started leaking a lot.

It was leaking between the plastic tank and the radiator on the driver side. Apparently this is pretty common because even the Autozone guys knew all about this kind of problem The plastic tanks on the sides heat up and expand at different rates than the metal causing the seal between the two to fail.

So 1 one trip to autozone, $150, and an hour later I had a new radiator and no leaks.

Hopefully this isn't the case for you, double check the hoses first then move onto the pressure test.
Good luck

 

Yep, been there and done that. But when my water pump went, it was like the bottom fell out of the bucket. No weep, just a levy break flood!

 

Determine where the leak is & fix it. Don't try to use fix in a bottle you will screw up your entire system if not right away later.
Craig

 

Is it a good idea to think about replacing the water pump if my radiator needs replacing?

 

Absolutley! Good access at this point...

 

ONLY replace the water pump if A: you can toss money around without care or B: it actually needs replacing.
You said it was leaking from the rad. Pressure test it & see where it's coming from. Why replace a pump when that isn't or might not be the issue?
Find the issue & go from there.

 

I have seen a minor crack on the radiator that appears that is where it is leaking. pretty positively that it will need a radiator.