Anti-Freeze leak and radiators

Rebel-Chevy · Post by **Rebel-Chevy** » Tue Mar 04, 2008 8:19 pm

so i been leaking antifreeze pretty good have to add some to keep the heat rolling every 4 or 5 days. where are some places i should check out for a leak? there is none in the oil so i think i can count the head gasket out.

Post by **HenryJ** » Tue Mar 04, 2008 9:27 pm

It will not be physically visible in the oil many times. Sometimes excessive condensation can be seen inside the filler cap or breather. Most often the oil just looks a little more opaque. Brown tinted and dirty looking.
If you are not finding puddles, I would suspect an internal leak.
Intake gaskets are the first suspect.
I don't know what year yours is, so it makes it hard to say they are high on the list. Early gaskets were not compatible with the extended life coolant. There were also problems with shrinkage and cracking.

If it is a head gasket, usually there will be excessive pressure in the system. There are hydrocarbon test kits available. Test the coolant for these. If it is positive, you have a blown head gasket.

Other areas of interest would be the thermostat housing. Look for an improperly installed seal, pitting and damage.
Check the freeze plugs for leakage. Pitting can lead to small leaks. The engine heater is installed in the left rear freeze plug hole. It has an O-ring that can get hard and fail.
Hoses and connections. Inspect the whole hose. The fan belt can come close to the lower hose. An old belt can let it come way to close. I have seen one earlier model rub a hole in the lower hose.

If it is externally visible track it down. If it is internal suspect the intake first. If nothing is found there dig deeper.

Rebel-Chevy · Post by **Rebel-Chevy** » Wed Mar 05, 2008 12:42 pm

its an 2001. you can smell it burning, and can see down behind the radiator it looks wet, i havent had the time to really put it on the lift and check it out. i was just wonder in the most common places of failure.

killian96ss · Post by **killian96ss** » Wed Mar 05, 2008 2:38 pm

Sounds like one of the radiator hoses or the cap, but it's also possible you need a new radiator.

You should also check the drain plug.

Steve

Post by **HenryJ** » Wed Mar 05, 2008 5:34 pm

Check the area around where the oil coolers attach to the radiator. I had mine leaking a little on the drivers side for a while. I am not sure why it finally stopped.

williamcstonejr · Post by **williamcstonejr** » Wed Mar 05, 2008 5:58 pm

It can also be going straight into the cylinder and out the tailpipe only, you should be able to smell coolant if you take a small wif of the exhaust. Not to much or you will be brain dead like me. If your emissions test centers are privatized like California you might be able to get the coolant and exhaust checked for a few bucks if they are slow. Around here a couple of guys have done it for me for a six pack. Not much to do since they don’t have to hook up to the dynamometer. In one minute they can tell you if it is coming out of the exhaust or going into the coolant. Most mechanics that do you a favor will gladly accept a little after work refreshment from you.

Rebel-Chevy · Post by **Rebel-Chevy** » Wed Mar 05, 2008 7:44 pm

i seen a little anti-freeze on the radiator about half way down, on the drivers side like on the frame of it, not the reeds. i dont know what it is tho, im too lazy to actually pull it in the garage and take a good look.

williamcstonejr · Post by **williamcstonejr** » Wed Mar 05, 2008 7:52 pm

Now you sound like me. I was so fed up with working on cars I refused to do it unless it was a high dollar labor item. This recent body shop/vacuum actuator got me started again. I know how you feel.

Post by **HenryJ** » Wed Mar 05, 2008 8:00 pm

Let us know when you get over being lazy and find out what it was.

roadrunner · Post by **roadrunner** » Thu Mar 06, 2008 1:33 pm

Rebel-Chevy wrote:i seen a little anti-freeze on the radiator about half way down, on the drivers side like on the frame of it, not the reeds. i dont know what it is tho, im too lazy to actually pull it in the garage and take a good look.

The best way to find your leak is to get hold of a cooling system pressure tester. Pump the pressure up to the cap rating and you'll discover in a hurry if you have an external leak anywhere. From your description above it sounds like perhaps the end caps on your radiator are leaking. Plastic caps on an aluminum core are prone to do this. I know. I've replaced several of my own over the years and several for customers as well. These radiators are more sensitive to vibration damage than the old copper ones. A radiator shop will tell you replacement is the best option if they are worth their "salt". Trying to "recrimp" the core to tank tabs is temporary help at best and don't even consider having the tank removed and regasketed as the "tabs" will likely break off or be weakened and leak again later. Hope this helps you.

snocat1 · Post by **snocat1** » Thu Mar 06, 2008 8:55 pm

It sounds like a leak I had. I had to get a new radiator. I had napa put it in had it fixed and 3 months later had to put in another one.

roadrunner · Post by **roadrunner** » Thu Mar 06, 2008 9:09 pm

killian96ss wrote:I just had the same thing happen with my 88 S10.

The radiator (only 1 year old) started leaking where the plastic end tanks and aluminum core are crimped together.

Luckily I bought one with a lifetime warranty so it was replaced free of charge.

I replaced the rad in my 90 park ave in 03. Thankfully I bought one with lifetime guarantee. Just failed a couple weeks ago. Still had my receipt. Car now has 297k on it. Also an aluminum core with plastic ends. Sure glad I got the warranty!

BTW all three died of same problem. Leaking tank to core gaskets.

Horsehammerr · Post by **Horsehammerr** » Mon Apr 07, 2008 12:05 pm

My '02 has a weeping coolant leak at the front of the intake. It's not spraying or running out but a leak none the less. How much trouble is this to change the gasket and what all needs to be replaced? I have a Chiltons manual,but it might as well be a Bugs Bunny comic book. They seem to think you can combine all S-10 motors together in the same repair information. Can anyone lead me to the right procedure ? Doesn't seem to be a post on this.

Post by **HenryJ** » Mon Apr 07, 2008 4:19 pm

Horsehammerr wrote: How much trouble is this to change the gasket and what all needs to be replaced?

Intake gasket replacement

Rebel-Chevy · Post by **Rebel-Chevy** » Mon Apr 07, 2008 5:30 pm

i probably need a new radiator but im gunna try some stop leak to see what it will do for the time being.

Post by **HenryJ** » Mon Apr 07, 2008 5:32 pm

Don't do it!

That stuff clogs the passages too. Not a good move. Only done if you are on your way to trade it in at the "jippo" dealership.

Fix or repair the leak. Don't clog the system.

F9K9 · Post by **F9K9** » Mon Apr 07, 2008 6:04 pm

HenryJ wrote:Don't do it!

That stuff clogs the passages too. Not a good move. Only done if you are on your way to trade it in at the "jippo" dealership.

Fix or repair the leak. Don't clog the system.

JaVeRo · Post by **JaVeRo** » Tue Apr 08, 2008 2:10 am

The plastic had cracked on mine. It was between the radiator and the AC coils and hard to see, about 1/3rd the way down on the driver side. If you take the top shroud off you should be able to see it pretty well. Use a pressure tester like roadrunner said and it will show up faster.

James

Rebel-Chevy · Post by **Rebel-Chevy** » Tue Apr 08, 2008 11:29 am

so i put a thing of stop leak in it this morning and then just before, after driving it a bit, i opened the hood and looked around and i herd a hissing sound and of corse i found a nice little crack in the plastic on the drivers side about 2 or 3 inches down.

roadrunner · Post by **roadrunner** » Tue Apr 08, 2008 12:15 pm

Gotta agree with Reed and Brule. You're gonna end up wishing you'd never seen the stop-leak.

BADs Crew · Post by **BADs Crew** » Tue Apr 08, 2008 3:54 pm

Read THIS and you may think again about Stop Leak. It will clog everything including the heater core.

Rebel-Chevy · Post by **Rebel-Chevy** » Tue Apr 08, 2008 4:24 pm

i didnt read the post in time to not put it in, it dont really matter ill be puttin in a new radiator in soon.

Post by **HenryJ** » Tue Apr 08, 2008 4:42 pm

Flush , treat and flush again, then repeat over and over. Do your best to get all that crud out before you install the new radiator.

Rebel-Chevy · Post by **Rebel-Chevy** » Tue Apr 08, 2008 4:43 pm

ill make sure of it

F9K9 · Post by **F9K9** » Tue Apr 08, 2008 5:15 pm

Rebel-Chevy wrote:............ it dont really matter ill be puttin in a new radiator in soon.

I am afraid it does matter. If, your heater core was "borderline" before the stop leak, it may be next on your list of repairs. That is one repair that I do not want to perform.

Tony · Post by **Tony** » Wed Apr 09, 2008 12:15 pm

Other than looking for external leaks, I would've gotten the cooling system pressure tested. Generally they can find where the leak is coming from that way.

My guess would be intake gaskets. My coolant never leaked, but it was always low even after I filled it. One day I started smelling coolant, had no heat and the car began to overheat.

Replaced them with Fel-Pro Permadry gasket set. Worked awesome!

Rebel-Chevy · Post by **Rebel-Chevy** » Wed Apr 09, 2008 5:24 pm

i found a nice crack in the plastic on the front drivers side, not sure how long it is but im goin to the yard on friday if its nice to find me a new one.

Post by **HenryJ** » Wed Apr 09, 2008 5:54 pm

Careful about junk yard radiators. If they have been dry too long the tank seals dry out and can be problematic. New is different. Once exposed to the coolant and heat they need the moisture to remain pliable. Sometimes when they sit for a while dry after use, they do not fair well when put back into service. This is even if they test good initially.
No more than the cost of a new one, that would be your best bet , IMO.

Under $150 for the extra capacity radiator, new.

green02crew · Post by **green02crew** » Wed Apr 09, 2008 7:50 pm

Yes Napa has some very good prices on the new larger radiators. That is where I will be headed eventually.

Post by **HenryJ** » Wed Apr 09, 2008 7:59 pm

Check them closely. NAPA here has cheap junk for radiators. I am not sure who just bought Modine, but I am not impressed.

JaVeRo · Post by **JaVeRo** » Thu Apr 10, 2008 8:36 am

RediRad has an oversize radiator for these trucks. I think mine was about $220, not sure.

I have been told that a crack on the driver side opposite the inlet port is usually caused by too much stress against the radiator hose/nipple when removing/installing the air filter cover. Mine cracked when I was still getting the free oil change service from the dealer.

James

Rebel-Chevy · Post by **Rebel-Chevy** » Thu Apr 10, 2008 12:12 pm

you could sort of see the crack in the plastic in this pic

http://i32.photobucket.com/albums/d5/R3 ... 01_006.jpg

i couldn't get the camera to focus in on it good.

roadrunner · Post by **roadrunner** » Thu Apr 10, 2008 2:45 pm

Listen to the Brule-man! You might spend a little more for a new rad but you'll be glad you did in the long run.

JaVeRo · Post by **JaVeRo** » Fri Apr 11, 2008 2:00 am

When you get the old radiator out, push on the hose nipple and see if it flexes the crack in the plastic. Just from looking at the picture, it appears that someone pushing the nipple to the left while trying to get the air filter cover out could have caused or contributed to the failure.

Just trying to verify if there is any truth to what I was told.

When I bought my first crewcab, the dealer was offering lifetime oil change service. I think they charged extra for the air filter about every other oil change. I took advantage of it until the truck got to 100k. I figured out there was just too much that was not getting done (greasing the idler arm among other things) and started doing the oil changes myself. My radiator cracked during this time.

James

green02crew · Post by **green02crew** » Mon Apr 14, 2008 10:33 am

HenryJ wrote:Check them closely. NAPA here has cheap junk for radiators. I am not sure who just bought Modine, but I am not impressed.

Would the Proliance and Modine be the same then since they merged? On Amazon I found one for $135 part #431405 but do not know if it would be the same as at Napa.

Post by **HenryJ** » Mon Apr 14, 2008 12:10 pm

That should be the correct part number. All that I have seen with that part number have turned out to be correct.

Go/Dan, TransPro, ReadyRad, Proliance.

green02crew · Post by **green02crew** » Mon Apr 14, 2008 4:37 pm

So would they all now be the "cheap junk" that you saw at Napa? Or are the ones at Napa somehow different?

Post by **HenryJ** » Mon Apr 14, 2008 4:55 pm

Last one I saw was probably last year. It was Modine and I was not impressed. Thin core. Thin reinforcement ribs. Poor fin count.
I show the NAPA radiator as NR 2560. My cost is $106.97
the description is as follows:
Product Features: Manufactured with Industry leading quality components using world class process,Make:GM,Core Size:26 1/4 x 15 x 1 3/8 (1 Row),Inlet Header Size:2 1/2 x 16 9/16,Outlet Header Size:2 1/2 x 16 9/16,Inlet Connector Size:1 5/16 Top Left,Outlet Connector Size:1 9/16 Bottom Right,Type of Mount:Pin,Oil Cooler:11 1/2 Transmission; 11 1/2 Engine,Comments:Plastic Tank Aluminum Core.

...using world class process

Does that mean Chinese copy?

I would be skeptical and want to look it over closely before purchasing. My guess is that they still use the weak tanks.

green02crew · Post by **green02crew** » Mon Apr 14, 2008 5:49 pm

Well I guess no matter where I got the radiator from modine/proliance/transpro they would all be the same. I show the same cost with shop account here as well, also adding a tranny cooler it would be very affordable under $150 all said and done.

F9K9 · Post by **F9K9** » Mon Apr 14, 2008 7:41 pm

green02crew wrote:..................also adding a tranny cooler it would be very affordable under $150 all said and done.

Would be an excellent time to do the hoses, coolant and belt. IMO. That is what I did and wish I had the efan swap all set to to go then.

green02crew · Post by **green02crew** » Mon Apr 14, 2008 8:31 pm

Belt just got done and hoses look fine. Efans would be ok but I'm not looking to head that direction as of now. The stock alternator is running great with the new pullies so I am in no rush to upgrade.

F9K9 · Post by **F9K9** » Mon Apr 14, 2008 8:50 pm

green02crew wrote:.................and hoses look fine............

I understand that but, it was directed at members who go strictly by appearances. I have spent many hours waiting on a club member who did not check their hoses and did not carry spares. I realize that the word has changed dramatically in thirty yrs but, I was brought up to replace them every two yrs despite their appearance. Change them in the convenience of your driveway or several hundred miles from home. That bottom rad hose is a bear and much easier to change in your driveway with the rad removed. Overkill? Probably. Wouldn't strike me that way while traveling 2K+ to the MOAB and a spiffy looking hose decided to fail. I am just being extra careful. If, trails and long rides are not in your future then please disregard my comments.

green02crew · Post by **green02crew** » Mon Apr 14, 2008 9:00 pm

It might have a little to do with environmental variables as well. Perhaps where I am located they are less prone to heat/dry causing them to crack? I will thoroughly check and if there is any sign of weaknesses they will be gone. I don't do much hardcore offroading just the occasional jaunt.

green02crew · Post by **green02crew** » Thu May 15, 2008 6:50 pm

Hoses were in great shape today when I did the radiator swap. No problems and very flexible still. Radiator only cost $109 with a Napa discount. Well worth doing.

F9K9 · Post by **F9K9** » Thu May 15, 2008 8:52 pm

green02crew wrote:Hoses were in great shape today ..........

Glad it worked out!