how do I clean coolant reservoir ???

[Loobed]

My 2001 GMC Sierra 1500 coolant reservoir tank is very dirty. There is scum on the sides and sediment on the bottom. The reservoir tank has baffles so it is almost impossible to get a brush inside to scrub it out. I tried soaking the tank with radiator cleaner, but that didn't work. I also tried Super Clean and Vinegar. Nothing worked.
I had Dexcool in it for 7 years (changed 3 times). I switched over to Prestone LowTox 2 years ago. When I switched over I did a thorough cleaning with heavy duty cleaner and several distilled water flushes. The scum was in there before I switched to LowTox.
I just don't like looking at the dirty tank. It makes me think the entire cooling system is dirty.

 

[dailydriver]

Can you get at least part of a power washer nozzle in there??

That's what I do when I want to clean the overflow tank in my f body, which is black and not transparent.

It blasts all of the "death-cool" gunk (this is the ONLY place it seems to collect) right out of there!!

 

[Samilcar]

I've heard of people taking off a dirty overflow tank, throwing in some marbles or ball bearings with a little bit of soapy water, then shaking the tank for a while to clean the gunk off the inside surfaces.

 

[S2500Dog]

Try to get a water hose in there or a nozzle and put it on a good setting where it will spray good in there and clean out the junk in there. If you suspect that the entire system may be dirty, do the above recommendations and change it over several times with Prestone LoxTox and Distilled Water flushes.

 

[defektes]

I used Copper BB's and dishwasher soap. Pennies will work too.

 

[CourierDriver]

I used vinegar,,yep old fashion vinegar,,,well it worked for me, it also kills that radiator smell too, I added a cup to the radiator,,no more smell.

 

[OilNerd]

I've had success with this method: remove the reservoir tank, fill with soapy water, and scrub using a wire toilet brush (cut it in the middle with diagonal pliers and bend it as necessary), and rinse.

 

[eljefino]

+1 on the automatic dish soap, it doesn't suds. I cleaned up residue from a cracked head with the stuff.

 

[Kestas]

Maybe a bottle brush will work. Like the toilet bowl cleaner, it can be bent into shape.

 

[1345]

My tank was filthy so I took it off dumped it all out filled it up with pool acid dumped it out and rinsed it out with water perfectly clean in just a few seconds.

 

[berniedd]

Originally Posted By: CourierDriver
I used vinegar,,yep old fashion vinegar,,,well it worked for me, it also kills that radiator smell too, I added a cup to the radiator,,no more smell.


Vinegar is acidic, not a good thing to add to your radiator water.

 

[Shannow]

Take the tank off and use CLR (Calcium, Lime and Rust remover).

It's a good cleaner, but takes a while.

 

[Loobed]

I can't use a bottle brush or put anything non-liquid/non-soluble inside the tank. The tank has numerous baffles that make any form of mechanical cleaning impossible. You have to almost see the tank to know what I am talking about. I can give an analogy of what it is like. Imagine trying to vacuum every room of a two story house by sticking a vacuum hose threw the chimney. It is virtually impossible, or not cost effective. I did not want to use any harsh cleaners like CLR or toilet bowl cleaners because some residue could remain in the tank and damage the coolant, radiators, gaskets, seals, or other metal parts.

I guess I'm stuck with a dirty tank

 

[Brian Barnhart]

You must be imagining things. Everyone knows Dexcool remains clean and sludge free in systems with pressurized overflow tanks, especially when it’s been changed 3 times in 7 years.

Now back to reality...
I’ve cleaned tanks like the one on your Sierra. It takes both time and work.

1) Remove the tank from the vehicle.
2) Take off all the tank’s hose connections.
3) You are going to get wet. Now is the time to put on a swim suit if you don’t like wet clothes.
4) Use a garden hose with a nozzle and direct a strong spray in every opening (there is at least 3 counting the filler). This should flush out a good bit of the sludge.
5) With as much water as possible in the tank, shake it vigorously and in different orientations while the water drains out the various openings.
6) Repeat steps 4 and 5 a few times.
7) Plug all the hose connections and fill the tank up completely with water and let it sit for a half hour or so.
8) Drain the tank and go back to step 4. Do this several times as necessary. It might also help to add some cleaner or soap for step 7.

I’ve cleaned two of the multi-cavity tanks this way, including one from a Sierra, and have gotten reasonably good results.

 

[Gary Allan]

Brian appears to have a plan. You're just going to have to get that stuff to get from behind the baffles by taking it's own sweet time.

I'm lazy and would tend to do some type of caustic solution and let it sit as long as necessary and flush as much as necessary to get'r done.

Perhaps alternating acidic and caustic solutions separated by a clean water rinse (to avoid excessively violent exothermic reactions).

Naturally this ties up the vehicle for more time than you may want to, but ....

This annoys me too. My tank is even fully accessible by a pressure washer. It still appears to stain easily and resists cleaning.

 

[George7941]

Originally Posted By: Gary Allan
This annoys me too. My tank is even fully accessible by a pressure washer. It still appears to stain easily and resists cleaning.


Gary, you should switch to Dexcool. You won't have to clean your tank any more. Here again is my Sierra surge tank with Dexcool in it.
The Dex is factory fill and the tank, or anything else in the cooling system for that matter, has never been cleaned.

See how the tank is crystal clear, with nary a stain on it.

 

[Stu_Rock]

I have had good results with automatic dishwasher detergent and scalding hot water. It seems that basic (high-pH) detergents work well on Dexcool sludge. Plug the inlet and cap and shake well.

Repeat twice without the detergent to rinse.

 

[Loobed]

I will try some of the tricks posted next time I have time.

thanks

 

[George7941]

Did you ever find out what generated the residue in the first place? There must have been an underlying cause. Some possibilities are
1)Stop-leak additives
2)tap water instead of distilled water
3)engine oil leaking into the coolant
4)low coolant level

Hopefully, the underlying cause has been fixed.

 

[saberz]

Can try amazon.com and buy a replacement for 90% off(genuine A/C Delco). Cost me $23 shipped compared to $90 at GM parts direct and over $110 at the dealer. That grime is tough as nails to clean up.

Discoloration can also occur from a Faulty tank cap(not keeping pressure). That can be had for $5-8 bucks shipped on Amazon as well.

I had a band tank and cap(tank was leaking and it was an orange/brown hue(coolant was clean)). Swapped tank and cap for less than $38 shipped and 45-60 min of time(all prep to prevent coolant spillage). If anything, after you clean the tank, buy a new cap for the radiator and tank, or just the tank if its a closed system like my G6.