Narrow escape from radiator leak, 91 GMC V2500 Suburban

[rocky_mtn_man]

Looking for some local references for a good radiator or radiator/AC shop.
I'm in Boulder, Colorado. Also tips on how to pull the radiator.

Was doing a short tow from Superior with hill climb and long descent into Boulder, check engine light came on and I was overheating. I was able to park it fairly quickly and still had burgling coolant in the block when I parked with the engine over a curbside snowpack. Took two gallons to refill, and when I drove a mile to repark I must have lost most of it (leaks under pressure). I replaced the radiator cap, that might be why it puked faster. I won't be able to test for a head gasket leak until I fix the radiator and can test the pressure.

The leak is from the center bottom, not the tanks or hoses. Can I get a radiator shop to put in a new core? This was a replacement radiator which I put in when I bought the beast in 2001. 5.7l with AC, 4WD, 3/4 ton

The AC has never worked (except when I replaced the compressor, and my mechanic tried to do a conversion, which leaked out in days). I've heard you should stay with r-12 and put in a parallel flow condensor, so this might be the time to do that project.

[daddyjeep]

I would think it could be re-cored, but it might be less expensive to just get a new one.

[Matt Man]

I still have the original harrison radiator from my 81, they wanted over 400$ to re-core it....I bought a spectre from summit for about 150$ been working fine for 2 years now so far.

[Edahall]

Originally Posted by rocky_mtn_man

The AC has never worked (except when I replaced the compressor, and my mechanic tried to do a conversion, which leaked out in days). I've heard you should stay with r-12 and put in a parallel flow condensor, so this might be the time to do that project.

That's correct however, the source of the leak needs to be found. You'll get better performance out of r-12 but it's harder to get and more expensive.

[Ski-me]

First of all, sweet ride! 91' 2500 is a rare rig. The only year an OD tranny was in the 3/4 suburban!

I'm down in the Springs. It's probably not worth doing a re-core....I'd just go get a new one. The engine radiator and the AC radiator are separate units so you don't need to mess with AC unless you want to.

The R12 is very expensive to get (if you can), so conversion is the way to go. It's not a cheap route though. I replaced everything because I certainly didn't want any contaminants to damage my new parts. Yours is going to be more because you have (assuming) a rear AC unit and lines go back there too.

[MikeB]

I bought a Murray aluminum radiator from my local O'Reilly Auto Parts for around $120. It works great and has a lifetime replacement warranty.

The biggest radiator they list for a 91 Suburban with 5.7 engine costs $144. If you don't have an O'Reilly Auto in your area, surely there is another chain store that sells radiators at comparable prices.

[Ski-me]

Originally Posted by MikeB

I bought a Murray aluminum radiator from my local O'Reilly Auto Parts for around $120. It works great and has a lifetime replacement warranty.

The biggest radiator they list for a 91 Suburban with 5.7 engine costs $144. If you don't have an O'Reilly Auto in your area, surely there is another chain store that sells radiators at comparable prices.

Yes, we have O'Reilly's here in Colorado so it does look to be available to the OP. Isn't the Murray aluminum radiator fins but plastic sides? This is all that I can see from the four: Autozone, Advance Auto, Napa and OReilly's. Napa does have an all metal one but that's $400 or so.

[rocky_mtn_man]

Turns out the 2 core radiator was probably fine after all. I bought a 4-core radiator for $140 at O-reilly, then drove to Keeter Trucking and told them I think I had a radiator leak and to swap in the new 4-core radiator.

I went back because we hadn't yet fixed the leak, and this time brought a new O'reilly water pump (even though it head been replaced 10 years ago).

I asked them to do a pressure test this time, and also asked them to fix the top radiator holding brackets that needed to be reworked to safely hold the new four-core.

They called and said the leak turned out to be what they thought were loose heater hose clamps, said the water pump was fine, and fixed up the clamps to use the factory bolts, all at no charge to me. O'reilly is great about handling returns.

I didn't complain about putting in a radiator I didn't really need, I told the shop it's a nice upgrade, and they agreed ("That's the way we see it too").

With my AC not working, the incoming vent air isn't as hot as it used to be, so I think the cooling is more efficient.

After messing around with replacing heater hoses, the leak got worse, so I bought a heater core but I am waiting on installing it (I've done this once before in a '74 Suburban), and installed a bypass hose with a 5/8" to 3/4" adapter just to get back on the road.

Lesson learned: don't be lazy and skip the cooling system pressure test and make shotgun assumptions based on a puddle under the radiator about what's leaking!