Many times the radiators break the plastic side tanks and there often around the hose attachment neck.

Thorough cleaning then brake cleaner and pressurize the system or let the car warm up until it opens the thermostat and watch.
Got lucky with just looking several times to identify leaks.

 

Thank for the replies. If it is somewhere on the radiator will pressurizing the system create the leak or make the leak visable? If it is the radiator itself is there a good site to go to for the removal? Thanks again for the help. Hv a gr8 day.

 

Pressurizing the system to confirm the origin of the leak is always good so that you don't just guess what parts you will need.

If you need instructions on the radiator removal and replacement, even a Haynes manual should have that. I might have scans of the instructions from my 99 service manual I could post, if you like.

 

I have acquired a radiator/coolant pressure tester kit but none of the adapters fit on my radiator or overflow tank so I have not been able to pressurize my system. Does anyone know where I can get an adapter to use on a 2002 Chevy S-10 Blazer ZR2 so I can do the pressure test to locate my coolant leak? I appreciate any and all help with this. Thank you.

 

I was able to do pressure test with a kit I borrowed from either O'Reilly's or Autozone.

 

Unfortunately the kit I have doesnt hv adapters that fit my yr make and model. I even got addl adapters and had one special ordered and none of them fit. My vehicle is a 2002 Chevy S-10 Blazer ZR2. I think thats the correct discription and what to put in any search engine for parts anywhere. If that is not correct plz let me know. When I do a search under Blazer parts or S-10 the parts often do not fit my vehicle. Thanks again for any and all help. Hv a Gr8 day.

 

That is so strange!

So I looked at the GM Parts Giant website to see if they have different radiators listed for the different models of Blazer in 2002 and they only have one for all, pn 15120548, which happens to be the same for my 99 4dr, 4wd one.

Is it possible you have a non-stock or non-OEM style radiator?

Did the pressurization kit include a generic adapter with a rubber part that can go into the throat of the radiator?

 

I finally got a pressure test kit that did fit my car with one of the adapters. I picked it up at Advance Auto at one of their main supply stores. This kit had 22 adapters in it. If anybody out there is having a radiator coolant leak problem I recommend you go to this store and pick up that kit. So I pressurize my radiator. I located the leak. Unfortunately it is approximately 2 in down on the right side of my radiator when you're facing the radiator in the front of the radiator. I also looked up the OEM part. I agree that it is 15120548. I have checked my radiator out thoroughly and looks like a match to.the pics I see on line for OEM part 15120548. I am ordering one as we speak or as I type. In the meantime before my new radiator arrives does anyone have any Quick Fix solutions that work so I'll be able to use my vehicle until my new radiator arrives? Thank you again for all of your help and advice and guidance. Have a gr8 evening.

 

Congrats on finding the leak.

I'd avoid putting any stop-leak into the cooling system. I've never heard of a leak in the small metal passages ofva radiator failing catastrophically. Thus if was in your situation and only had to drive around town short distance, I'd keep on driving it while carrying extra coolant around with me.

For added peace of mind, you could experiment with the old trick of loosening the radiator cap to keep the system from pressurizing. This will limit the boiling point of the coolant, but could slow down the loss of coolant from the leak. But of course, coolant could be lost from the loose radiator cap.

 

I replaced my radiator with a new OEM model with the help of a friend. It fit great. There were some issues in removing my old radiator and obstacles to put in the new radiator. Things that I did not see on any YouTube or any other self help videos. So I am including some pictures showing what you have to do or what I had to do to put in my new radiator. I hope these are helpful to anyone who owns or works on a 2002 Chevy S10 Blazer ZR2 model like mine. The pics should show that in order to attach the upper coolant line I had to remove my air cleaner cover, filter and air cleaner box in order to reach and be able to put in that upper coolant line. Then you have to put the air cleaner box back in and you can put the air cleaner itself back in but then attach the upper radiator hose. Then after you have that attached that coolant line and hose you can put the top of the air cleaner back on and you have to work it underneath the upper radiator hose has the pictures show. I hope the pics and my explanation are helpful. Thank you for all the help and assistance and suggestions on how to handle my coolant leak problem. Have a gr8 day.