Coolant overflow tank gunky (1 Viewer)

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Long story short I installed a new radiator and have green coolant. I noticed that my overflow tank has a gunky red-like substance on the inside walls of the tank and the hose on the inside. Almost a muddy-like substance. I was thinking of cleaning it out soon but was also just curious if this is a known issue and what the best way to wash it out is...do I need to use distilled water?
 
Pull the cap off the bottle and pull the bottle from it's metal holder. Sounds like there was red anti before adding green and needs a good flush again.
 
Long story short I installed a new radiator and have green coolant. I noticed that my overflow tank has a gunky red-like substance on the inside walls of the tank and the hose on the inside. Almost a muddy-like substance. I was thinking of cleaning it out soon but was also just curious if this is a known issue and what the best way to wash it out is...do I need to use distilled water?
Is the red substance slimey? When my rad leaked trans fluid into the cooling system it left alot slime in the overflow bottle. But is was a little more brown then red
 
Is the red substance slimey? When my rad leaked trans fluid into the cooling system it left alot slime in the overflow bottle. But is was a little more brown then red

It's slimy on the inside of the tank I would say, but I wouldn't consider it brown. Pic below for pretty good representation of the color...it is more of a Oklahoma red dirt color (which happens to be where the truck was for approximately 10 yrs of its life). You can also see the color of the fluid on the underside of the hood below from when the top of the radiator popped. I had an LC specialist replace the radiator and they didn't mention anything out of the ordinary.

overflow tank red.jpg


radiator explosion.jpg
 
That almost looks like the same residue that DexCool (the red/orange coolant) leaves when it dries. What's the history of the cooling system, or is this a new truck to you?
 
That almost looks like the same residue that DexCool (the red/orange coolant) leaves when it dries. What's the history of the cooling system, or is this a new truck to you?

Essentially new to me. The original rad was on it when I purchased over a year ago. I will dig through the receipts, but I believe the only work was general maintenance and replacing the hoses once. During the last year I replaced the hoses, coolant, and radiator with an all aluminum.
 
Did you FLUSH the system with distilled water, with the heater valves ON, and multiple times before installing the green coolant? If not, you MAY want to consider doing additional flushes, as the red/green do not like each other and they create a brown sludge that can lead to clogging and flow problems. Make sure your radiator cap is clean and operating properly, as mine was caked on the spring from the mix from the PO and did not relieve properly.

When a flush is done it SHOULD also include cleaning out the overflow bottle each time.
 
Looks like rust, a system that hasn't been well maintained. A long flush, garden hose at full blast should get most of it, may take chemistry if you want to get 100%.
 
Looks like rust, a system that hasn't been well maintained. A long flush, garden hose at full blast should get most of it, may take chemistry if you want to get 100%.


Did you FLUSH the system with distilled water, with the heater valves ON, and multiple times before installing the green coolant? If not, you MAY want to consider doing additional flushes, as the red/green do not like each other and they create a brown sludge that can lead to clogging and flow problems. Make sure your radiator cap is clean and operating properly, as mine was caked on the spring from the mix from the PO and did not relieve properly.

When a flush is done it SHOULD also include cleaning out the overflow bottle each time.

Well I certainly hope an LC specialist shop would flush the system when installing a new radiator and putting in new coolant.... I can always confirm with them though. I assume they just didn't clean out the overflow tank. I will take a garden hose to it then wash the tank with distilled water.

No issue with radiator cap, although it is only a couple of weeks old.
 
Rust, and if it was not flushed properly it will continue to circulate, again the heater valve catches many out, you need it to be set to hot with the ignition on, otherwise you get a heater full of rusty water mixed with your new coolant.

regards

Dave
 
Well I certainly hope an LC specialist shop would flush the system when installing a new radiator and putting in new coolant....

One would hope, is the same type of stuff in the radiator?

I assume they just didn't clean out the overflow tank. ...

Soaking/washing it with some CLR is often productive. Sometimes a hand full of gravel and shaking helps.
 
Yup! My vote says rust. Likely a previous owner ran straight tap water in the cooling system for a while. Even though it is an aluminum head and /brass radiator, it is still just an iron block which will rust when run without the protective benefits of most brands of coolant.
 
One would hope, is the same type of stuff in the radiator?



Soaking/washing it with some CLR is often productive. Sometimes a hand full of gravel and shaking helps.

I use dry rice with water and soap or coolant when I do the shake/rinse thing just in case I don't get all the residue out. At least I'm not putting a mineral-based abrasive back into my system when I'm done.

Just FYI.
 
I used a half a cup of my sons bbs from his air rifle added to the overflow tank with some purple power bbs make a awesome scrubber in a tank all of the smeg came out
 
Yup! My vote says rust. Likely a previous owner ran straight tap water in the cooling system for a while. Even though it is an aluminum head and /brass radiator, it is still just an iron block which will rust when run without the protective benefits of most brands of coolant.

I think so too, in fact mechanic said the coolant seemed diluted when they swapped the radiator. So maybe not straight water.


Well I certainly hope an LC specialist shop would flush the system when installing a new radiator and putting in new coolant....

One would hope, is the same type of stuff in the radiator?

I popped the cap and there was a tiny bit circulating near the top. Most of the gunk is above the coolant level line, so probably only a bit gets washed in there from splashing around.

I use dry rice with water and soap or coolant when I do the shake/rinse thing just in case I don't get all the residue out. At least I'm not putting a mineral-based abrasive back into my system when I'm done.

I will probably spray water & soap, shake like crazy, use a soft bristle scrubber I have that will fit in there, then flush with mineral water, re-fill with green coolant, and put that sucker back in place.
 
I had a similar or same issue. Have you had any of the radiator hoses off? Check the aluminum piping to see if there is residue there as well. I ended up having to get all new hoses, new radiator, new aluminum elbows and a new overflow tank as well. I still get some residual brown from the heater core I assume, but I'm not digging that out atm.

I assumed mine was from some type of stop leak put in the system by the PO, but the system was close to dry when I picked the truck up. Here are a few pics of what mine looked like.


My overflow cap looked exactly like yours does. I'm not saying you need to run out and get all new parts. My truck ran just fine with the old parts, the coolant was just always brown.

 
Flush ASAP
I had a similar or same issue. Have you had any of the radiator hoses off? Check the aluminum piping to see if there is residue there as well. I ended up having to get all new hoses, new radiator, new aluminum elbows and a new overflow tank as well. I still get some residual brown from the heater core I assume, but I'm not digging that out atm.

I assumed mine was from some type of stop leak put in the system by the PO, but the system was close to dry when I picked the truck up. Here are a few pics of what mine looked like.


My overflow cap looked exactly like yours does. I'm not saying you need to run out and get all new parts. My truck ran just fine with the old parts, the coolant was just always brown.


Wow that is WAY worse than mine. My coolant is still green, there is just a small thin layer of gunky stuff scattered on like 50% of the walls of the overflow tank, above the coolant level. And the cap was never gunked up like that, even before the radiator swap (I noticed the red, but since coolant was red, I figured it was that, and was also naive about it I think).
 

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