Any radiator cleaning tips??

[MiltonV]

I got today an original and in very good shape rad, but I see some tubes clogged, I honestly don't want to send it to a rad shop since I know the first thing they do is desolder it and this one is untouched and would love to keep it like that...if possible.

So is there any tip to clean the rust clogging some tubes without opening it?

[Charlie69]

Best way to clean a radiator is having a radiator shop clean rod and repair.  I run a Radiator Flush through my radiator every 2 years when I change anti freeze.

 

[datzenmike]

Clogged? as in hard water scale? Hard water has a lot of dissolved limestone and other minerals in it. My (soft) water is piped from a mountain lake so it's almost still rain water or snow melt. Kettles collect scale from hard water that boils away leaving the minerals. 

 

This is easy to fix, take it out lay front down with the rad cap on and fill with CLR. This will fizz and dissolve the scale won't hurt brass or solder. From now on only top up with distilled water.

[MiltonV]

2 hours ago, datzenmike said:

Clogged? as in hard water scale? Hard water has a lot of dissolved limestone and other minerals in it. My (soft) water is piped from a mountain lake so it's almost still rain water or snow melt. Kettles collect scale from hard water that boils away leaving the minerals. 

 

This is easy to fix, take it out lay front down with the rad cap on and fill with CLR. This will fizz and dissolve the scale won't hurt brass or solder. From now on only top up with distilled water.

CLR?? What is that?

No it looks like rust, also the reddish color of rust.

[Charlie69]

[MiltonV]

3 hours ago, Charlie69 said:

Ahhh gotcha, thank you..👍🏻

[Charlie69]

You are welcome.  Let us know how it comes out.  I have never used CLR but Mike Is very knowledgeable on these Datsuns.  I know CLR works great for household cleaning.

[MiltonV]

I am in Costa Rica (not Puerto Rico), 😅

So I don't think I would find such product here, maybe Walmart but I doubt it, anyways I loose nothing checking it.

Will let you guys how it went but certainly I have to do something.

[datzenmike]

I did mine but couldn't get back to it and is sat for 3 days so it only dissolves the calcium or limestone and is safe. Never tried it for rust but should work on it also. Rust is from a previous owner not using a 50/50 water/antifreeze coolant mix. What's happening is the insides of the iron block are rusting.and antifreeze will prevent this. When done with the rad you should flush out the block and heater core with a garden hose and get as much out as you can.   

[Charlie69]

If you can get the Prestone flush cleaner, drain your cooling system, remove your thermostat, put the top readiator hose back on with no thermostat.  Be sure if you have a heater it is turned on so the water flows through the heater core also.  Fill with tap water and the Prestone flush cleaner, put your radiator cap back on.  Drive the truck for a couple days if possible.  After driving let the truck cool down and drain the cooling system.  Fill the cooling system with tap water and run the engine until it reaches operating temp then shut off let cool and drain again.  Repeat this until the water being drained comes out clean.  Look and see if this helped to cleanout the cores.  If not pull radiator and have a shop clean rod and repair.  The rodding is where the shop takes special shaped (shaped to fit the shape of the tubes in your radiator) steel rods and push them through each tube in the radiator to clear any blockage.  tthe cleaning is they hot tank the radiator.  The hot tank is a heated tank of caustic soda solution that your radiator is submerged in and left for a period of time.  After the radiator is cleaned the tanks are soldered back on.

[datzenmike]

This a J13 engine? There should be a block drain just to the rear of the distributor. Use that to thoroughly drain the water jacket.

[Stoffregen Motorsports]

On 5/23/2020 at 7:51 PM, MiltonV said:

I got today an original and in very good shape rad, but I see some tubes clogged, I honestly don't want to send it to a rad shop since I know the first thing they do is desolder it and this one is untouched and would love to keep it like that...if possible.

So is there any tip to clean the rust clogging some tubes without opening it?

They don't have to disassemble the radiator. You can ask them to dip it in their tank without any other work included.

 

I would also ask them to not paint it. I hate radiator shop paint jobs.