Why does a radiator wear out and how can you tell when you need to replace? (1 Viewer)

[Beej]

Hi folks,

I'm doing another coolant flush in the coming month before I head on a trip to CO, UT, NV this summer.

I know the cooling system is a weak point for Cruisers and I have a temp read out and will be doing the RavenTai mod. My Cruiser has never run hot; I haven't seen the temp go above 190*F but then again, the ambient temps have always been mild or even downright cold (im in the Northeast).

A new radiator is about tree-fiddy, and while thats not breaking the bank, its a cost I would hope to avoid if I'm being honest. I love my PM but how does a radiator even wear out? Gaskets get old, bearings wear down, there's a leak here or a leak there. What is the radiators issue? Its made of aluminum; whats the malfunction?

Inquiring minds want to know!

Thanks in advance for any replies.

-- Beej

 

[ZackR]

I would say it has to do mostly with the plastic portion of the radiator expanding and contracting over the years. If the whole unit was metal and had perfect maintenance it seems that it could last the life of the vehicle.

I'm no expert on cruiser radiators but I would say 10 years is what I'd expect from most automotive radiators under normal use.

 

[mct75]

Being in contact with dissimilar metals causes the metal in the radiator to dissolve into the coolant. Thermal/pressure cycling causes mechanical stress due to expanding and contracting hundreds of times.

Using the proper coolant greatly helps the corrosion issue, but you'll always have the mechanical stresses to contend with. For a radiator to be most effective, the metal needs to be as thin as possible, so it's a balancing act.

 

[inkpot]

Radiators DO have gaskets that can fail. They are rather rigid and they take a lot of movement and vibration. They often have internal pressure and antagonizing chemistry. They also put up with thousands of hot n cold temp cycles. 20 ish years is a pretty good life span all considered.

 

[hammerheadfistpunch]

Before this happens...

 

[Kaninja]

My 21 year old rad just started seeping where the top tank meets the main part of the rad. I would think with summer approaching and your rad is anywhere near 20 years old, replacing it would be a smart PM.

 

[bicycleagent003]

Check out that video above - that's our collective future if we don't swap out these plastic tank rads as PM. I just replaced mine with a Koyo from Amazon which I paid about $125 for. I think we should all be replacing our OEM radiators at this point. I would have liked to get an all metal CSF, but I couldn't justify the price difference. Good luck!

 

[LS1FJ40]

Spend the tree-fiddy and enjoy the piece of mind. The last thing you want is to dump all of your coolant and overheat.

On my 1992 3FE the original radiator lasted 17 years. The aftermarket replacement last 8+ years. The aftermarket was a full metal version.

On my 1993 1FZ-FE the radiator blew on the PO and caused the HG to blow.

 

[BILT4ME]

When my radiator decided to let go, it was a catastrophic event for the radiator. No limping it home. It blew the top of the tank in a linear split the length of the tank, right down the middle. That was 3 years ago with about 210K on it.

The PO did not take care of my cooling system and it was full of crud due to coolant types being mixed as well as aftermarket cogged belts.

If you THINK it could be an issue, better to get on it and take care of it. It's only a matter of time. Unfortunately, that's one that you won't know is a problem until you're working it hard.

Depends on your comfort level.

My coolant now looks like fruit punch Gatorade it's so nice.......

 

[Beej]

Thanks for all the replies!

Will check out video later (work blocks Instragram)

Is there any way at all to tell if your radiator is getting ready to eat it OR when it was manufactured? No records for my truck so could be original; may not be, I don't know.

 

[Eicca]

Better to just do it and have the peace of mind. I'm replacing the radiator in my Lexus later today. It's at almost 20 years and 200k miles and still hasn't developed any leaks, but it's time. Don't want to get stranded anywhere.

Which reminds me, the parents' 100-series ought to have its radiator done too. No leaks there either yet but I don't want mom calling me in the middle of school stranded somewhere.

 

[ZackR]

@Beej - If you are concerned or don't have a record of replacement I'd recommend getting it done before the trip. You are looking at a lot of miles in places with few resources for this kind of repair if it blows out. Out of the crazy PM nature of the forum this one is actually worthwhile.

The problem with the plastic tank radiators is how quickly they fail (catastrophic as others have mentioned). The metal ones usually start with a small leak that can be limped home with some stop leak if necessary.

Nothing says buzzkill like being stranded in rural Nevada with a blown radiator. Not sure if you have spent much time out west but the distances to civilization are massive compared to the NE.

 

[Beej]

And this Koyo is the deal 'Mud knows and loves; is that right?

Koyorad® 1918 - Radiator

 

[Beej]

Before this happens...

Dang. Just like that.

 

[nuclearlemon]

even if your radiator doesn't blow, you will have "gunk" in your coolant that will collect in the passages of the radiator and limit the cooling capacity. i've always been lucky until last year, but on a 20 year old rig, just spend the couple hundred bucks and throw a new radiator in. i can tell you how much it sucks to have to do 40mph home on an 8 hour trip with the windows open and the heater cranked in the middle of summer

 

[midfat]

My cruiser is at 212k and was neither neglected nor cared for. Serviced when it needed something. My radiator just let go this weekend. I suspect that 20 years will prove to be the service life of these units. Inside the radiator looked great. I vote for PM and swap it.

Here's my failure:

 

[bloc]

Thanks for all the replies!

Will check out video later (work blocks Instragram)

Is there any way at all to tell if your radiator is getting ready to eat it OR when it was manufactured? No records for my truck so could be original; may not be, I don't know.

Typically the plastic tanks turn from black to brown as they start to lose integrity.. similar to the heater control valve on the firewall. Usually if the metal core starts to fail it'll happen a lot more slowly.. you'll see white crust as the hot coolant leaks and the water evaporates away. Not good but not nearly as bad as a plastic tank starting to give up.

 

[DirtScaresMe]

Mine's started to seep a bit at the top, where the plastic meets the metal. Barely a drop, doesn't ever pool under the vehicle. I have an oem I'm dropping in this week before a long desert trip coming up.

It's lasted over 20 years, would be happy to get the same.

 

[dcx13]

Caught mine with about a dozen hairline cracks along the front of the upper tank. The foam weatherstrip had been hiding it for who knows how long. Was running errands & caught a whiff of antifreeze when I walked around the front. Popped the hood, spotted a tiny whisp of steam, and found a webbing of fractures & stress risers. Limped home & ordered a replacement. New radiator, hoses, thermostat, heater valve & phh, along with one of Landtank's blue hub fan clutches from @NLXTACY. Added in a Koso temp gauge while I was at it. So far, highest temp I've seen is 186°F. Heading from SF to the Rockies, and back via Moab in June, so I'm glad I found the radiator issue when I did!

 

[Qball]

Just replace it!!!!!