The Stovebolt Site Forums The Shop Area General Truck Talk Radiator rust n gunk. How to clean?

I took the hoses off the radiator and removed the thermostat housing (which didn't have a thermostat in it. Hmmmmm...) and lemme tell ya. It is rust city in there.

I flushed the radiator with just water for now but, what do you guys recommend for cleaning out the cooling system or can that be done?

I'm not sure if my radiator is toast or not. I drove about 12 miles today and when I got home it was hotter than hot and steaming. I didn't see a leak anywhere except from the radiator cap. I'm replacing the hoses and putting in a thermostat but, is there an effective radiator flush that will help loosen and remove the rust thats in there and in the engine?

Thanks. (I searched the board but it didn't come up with anything relevant. (either that or my keywords stink..lol))

I have had good results with a product called Iron Out. You can purchase it at a plumbing supply store or Home Depot type store.Run the engine for about 1/2 hour, then flush with plenty of clear water.After it runs clear,add anifreeze and rust inhibitor.

You can always get muriatic acid from the hardware store and dilute it with water to reduce it's acidity.
Use outdoors only and be careful finding the right dilution - full strength will eat soft metals like brass and copper very quickly. - Works even better when heated.

In the end you will find that nothing can restore an old clogged raditor like a complete recore.
Once they are clogged, they can never be completely brought back to like new condition.

rsavage,

It sounds to me that indeed, your radiator is 'toast'! If your truck started steaming, even without a thermostat, there was a root cause. Aside from improper timing, a long pull up a steep hill on a hot day, or a plugged block (rare), the usual culprit is a old plugged radiator.

Proper engine cooling is the foundation of the entire system. As was mentioned above, a new radiator, or a re-core, is the solution to this problem.

Stuart

Is your radiator a "honycomb" style?
I was told those style couldnt be "rodded out" or cleaned.
So...what they do is keep your top and bottom tanks and re-core the actual radiator portion.
As far as running without a thermostat,,NOT GOOD!! Your coolant moves thru so fast it doesnt have time to be cooled by the radiator. The thermostat slows it down so it has time to let the radiator do its job.
Marty

Remove the plug on the lower rear of the drivers side on the engine block. If it doesn,t drain poke something in till it does. Flush it real good with water till it runs clear. Pull the radiator & take it to a radiator shop to have it cleaned & tested or buy a new one. Chances are 10 to one 1 it will need a new one or recored. Put a 180 degree therm. & a 4-7 lb. pressure cap.

I don't know if they are still available but they use to make a flush kit for cars and trucks which had a plastic tee fitting that went in outlet side of the heater hose and let you reverse flush the system back through the radiator. I have found when flushing the cooling system it is good to take the two heater hoses loose and with a small piece of pipe connect them togather to prevent pushing all the engine sludge back into the heater core. Tee connection allowed you connect a garden hose to the system to provide a constant flow of clean water. A replacement radiator may be cheaper than a re-core in most cases due to the labor involved. Good luck and let us know how it works out.

Thanks for all the suggestions!! I was running it last night and can see now that no additive is gonna help the radiator. I was recommended some stuff called "Max 13" (well, that was the old name. Not sure what the new name is. Its from Napa.) Its to get the rust and scale out. I tried it but ended up taking the radiator into a place thats going to re-core it. Not as expensive as a new radiator but the price is still up there.

At least once I have it, hopefully the truck will run nice and cool. It has new hoses, new thermostat, and it will get a new radiator.

If I'm missing anything, lemme know!

Thanks everyone!!

check hoses .therostat and water pump for lesks.a new rad will solve the problem in the long run.The old rad is pretty thin .waiting like a boom .It,s your thing. Pay me now or later

rsavage.

FWIW, I just checked with my local rad shop regarding my '48 3100 and getting a re-core. The quote was about $230 for copper/brass, and about $120 for an aluminum one with custom top tank. Since I am not going original resto, I am going for an aluminum core.

You may want to check with your local rad shop. They may be able to salvage yours as well.

Running without a thermostat is only recommended if you are running orifice restrictor plates as they do in racing. However for the street, never a good idea as the block temp is not regulated.

Scott

While you have everything apart check the heater core also, if the radiator is pluged the heater core will be also. Just a a sugggestion better now than later winter is here at least for some of those here. Sunny So. Cal.

Worked for 7-months at a Cat dealer repairing radiators and heat exchangers (bad, bad, experience). We used caustic soda to boil out the nasty stuff. 9 times out of 10 we installed a new core or we popped the tanks and rodded out the tubes individually. They are actually simple to repair but you need the right equipment to do it well. You did the right thing taking it to a shop. Just as a side note I bought a brand new U.S. made radiator from LMC for $240

I hope this isn't a silly question but, where is the heater core? Also, should I replace the water pump while I'm at it?

Thanks again everyone for the suggestions. I am really learning a lot!

The two tubes or hoses coming through your passenger side firewall lead to the core.

Ahhhhh.. Thank you. Ok, will check that.

Is there a way to test if your water pump is in working order?

"Remove the plug on the lower rear of the drivers side on the engine block."


Ok, this is the bolt looking thing on the very bottom of the very back of the block on the drivers side, right?

I'm going to give it a try tomorrow. Don't want to screw anything up. Just unbolt, remove drain and replace? Will I need any sealant or anything for when I put the bolt back into place?

Thanks again.

It has pipe threads, so a little pipe sealant would be a good thing. I keep teflon pipe sealant and hydraulic thread sealant handy at all times. I try to stay away from the teflon tape

Ok, pipe sealant. Check.

One last question...

On the advice of removing the bolt on the bottom of the engine and flushing it out, can I do that while I have the radiator removed?

You know, like take the thermostat off and stick a hose down the hole and see if water passes through and out?

Or should I wait until I have the radiator back on and flush the whole system with the truck running.

Just figured if I could maybe get the old rust kinda flushed out before the new radiator goes on I could prevent a lot of that gunk from circulating through the new radiator.

(excuse me if my posts make little if any sense.. I'm running on pure Nyquil tonight.) *achoo!*

*edited for awful syntax*

Any thoughts on putting the hose down the front of the engine and draining it that way before I do it? (see above post)

I sure don't want to mess anything up.

Thanks in advance.

Good idea. With the therm. out you can run the water hose in & flush out the loose particles. Some of it will come out the water pump but thats OK.

*whew*

Thanks. I didn't want to do anything I'd be regretting later.

I'm off to flush. lol!

Look out rust! I'm comin' to getcha!

YAY!!!!!!! I did the flush that I was asking about and got a LOT of rusty water out. Ran the hose while keeping my hand on the lower radiator hose and the heater hoses to keep the water in, then let it all spill out. Did that no less than a dozen times until it ran completely clear.

Just after I got done doing that, I got a call that my radiator was ready and to come pick it up!! Whooooohooooo!!! So went and picked it up and new heater hoses, came home and put it all back together. Once I got it hooked up, I filled it up with a bit of antifreeze and to the top with water and let it run for a few then drained it off to make sure I got stuff out of the engine as well.

Tightened the plug, filled him up, added rust inhibitor/water pump conditioner and made sure the thermostat was going to do its job. Right at 180, it opened up and sucked up the water just like its supposed to. To put it mildly, I was quite the happy girl!

I took him around the block 6 or 7 times just wavin' at the neighbors like I was the leader of a parade.

Grunt is now ready for his brake-light and then we'll be street legal!

Yaaaaaaay!!

Thanks everyone for the input and support.

Oh and, I think the heater core is fine. Turned it on and lemme say... it is gonna be one HOT winter! Dang that sucker can blow some hot air.

*can't wait for daylight. Gonna take it for another spin.*

Savage, Well Done we knew you could solve the problem. Now get the brake lighting working and enjoy.

Thanks 41Chevy! I drove it quite a bit today trying to get the feel of it and figure out some of its quirks. I need to research the electrical portion of the board and see what people say about the brake light wires. I can't get mine to light but will keep working on it.

These ol trucks sure weren't built for speed but they're kinda fun to drive. I got a lot of compliments and that makes it all worth it.