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Do we need to change that Long Life Coolant anyway?

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 #287853  by Arved
 
I'm looking for some recommendations on Cooling System Flushes.

I've tried Prestone's Super Flush, and when I opened my upper radiator hose, I still had a layer of rust in my upper radiator hose and the engine inlet fitting. There's still rust in the coolant recovery tank that I can reach in and wipe my finger with. So IMHO, that product is next to useless. It did a better job flushing my wallet than my cooling system. This is a product that's supposed to be run with the engine at operating temperature (and the heater blowing) for 10 minutes after reaching operating temperature.

I'm currently using Peak Super Cleaner and Flush. This is put in the cooling system and run for 3-6 hours, and thankfully, it's OK to run this intermittently. Finally found a use for the E/T timer in my overhead console! Anyway, I just started this, so I'll see how this works out.

I've heard here and on Bob Is The Oil Guy about using Cascade dishwashing detergent, but I have no idea how this would work on getting rust out.

How'd the rust get there? I had a pinhole leak in my radiator, and kept adding water to the system. I figured here was no sense in replacing with 50/50 since this was short-term problem, but it took longer than I expected. The coolant quickly lost it's corrosion resistance properties. I'm sure that having a water pump with a cast iron impeller (Bosch) instead of a plastic impeller is a major factor. There isn't that much iron/steel to rust with our aluminum blocks, aluminum heads, and aluminum radiators. But, there is a fine layer of rust seemingly everywhere.

Am I on the right track with the Peak brand flush, or is there something else I should be looking at to get the rust out? I don't think C-L-R or any of the other household rust removers will hold up to the cooling system temperatures. Adding an acid doesn't make sense to me, as it would only make the coolant an electrolyte, making the possibility of galvanic corrosion (between dissimilar metals, like the aluminum engine block and cast iron water pump impeller) worse.
User avatar
 #287856  by Maximus
 
What..... I have never seen rust in a cars radiator in a very long while. Also never use that preston crap. You need to flush with distilled water.
Rust, I don't think its possible to have rust.
User avatar
 #287869  by Bill Putney
 
If you want to try a physical forward and reverse pressure flush, you might read this: http://300mclub.org/forums/viewtopic.ph ... 50#p266950
That should take care of any thickness buildup, partial blockages, or loosely attached residue.

Bob (not the Oil Guy but FireM) swears by the cascade treatment. If he says it works, I'd believe it, and also that there probably isnt anything that is going to be as effective while also being safe for your system.

Unless your system is hosed beyond repair, I would think doing Cascade *and* pressure/reverse flushing would be everything you could do without taking things apart. Then using 50/50 of the correct stuff (G-05 of course) should prevent any future problems.
User avatar
 #287875  by Arved
 
That's tempting, Bill. To flush the block, you've got to take out the thermostat, right? Not much water passes when it's cold. Only a little through the "jiggle valve." That's been my major complaint with the Prestone Flush N Fill Kit. And removing the thermostat on the 3.5L is, as far as I'm concerned, a major PITA. I'd rather change inner tie rod bushings. :(

I have a lot of reservations about using Cascade with aluminum. Aluminum is a very reactive metal, and automatic dishwasher detergents are caustic. Unless this is done with a much lower concentration than a typical dishwasher (which discolors the aluminum bottoms on my SS pots and pans), I'm afraid this will do more harm than good. :|

Other than the rust (and yes, there is rust), I'm certain my cooling system is good. No slime, no goo, and the only discoloration in the water is a slight redish-brown from the rust.
User avatar
 #287883  by mnitetrain
 
Tap water/city water/well water?? Any staining or buildup in bathtub or shower?? Might be deposits in water that boiled out. Use distilled water when you refill with 50/50.
User avatar
 #287884  by Bill Putney
 
Arved wrote:That's tempting, Bill. To flush the block, you've got to take out the thermostat, right? Not much water passes when it's cold. Only a little through the "jiggle valve." That's been my major complaint with the Prestone Flush N Fill Kit. And removing the thermostat on the 3.5L is, as far as I'm concerned, a major PITA. I'd rather change inner tie rod bushings. :( ...
Remove the lower radiator hose on one end, then flush the radiator in both directions. Block can be flushed thru the bypass (disconnect near reservoir)? But - yes - probably more effective with thermostat out. Flush heater core in a separate operation.
User avatar
 #287887  by FIREM
 
The only steel that I can think of that may give you rust in the cooling system are the heater pipe unedr the lower intake and the heater hose "Y" pipe near the starter. Other than that, the steel impeller as noted. May want to check these pipes as best you can for evidence of leaks.
Cascade, if used must be flushed well. Agreed it may be slightly caustic but it cleans well, espically if the system was contaminated with oil.
Bill's back flush device will really clean out anything in the system for sure..
User avatar
 #287891  by Arved
 
FIREM wrote:The only steel that I can think of that may give you rust in the cooling system are the heater pipe unedr the lower intake and the heater hose "Y" pipe near the starter. Other than that, the steel impeller as noted. May want to check these pipes as best you can for evidence of leaks.
Water is moderately hard here. Some use water softeners, but I haven't found a need, and I grew up around very soft water ("East Bay MUD" - San Francisco East Bay Municipal Utility District). 90% of the time I use distilled (or deionized) water, but having to refill the cooling system every day (or risk overheating on the day I didn't), stocking distilled water became a chore, so I refilled with tap water.

We're in agreement on the sources for potential rust. This with a more conventional water pump that has a plastic impeller have a LOT less rust producing iron in the system. I recommend avoiding Bosch water pumps (mine was purchased at Pep Boys). I didn't have any choice with my car on the tow truck on the way home after a $1200 estimate (that I couldn't afford) to change the pump. I bought the pump and timing belts and did it myself last spring (25K early for the timing belt).

Steel doesn't rust as fast as cast iron. I'm sure I'm seeing rust from the water pump impeller. There's a lot of cast iron there to rust, and cast iron tends to rust faster than steel. Add to that any potential cavitation issues (most coolants are formulated to resist cavitation) around the impeller, and the fact that it's sitting there mixing it's rust with the water, there is little left to the imagination about what and where the rust is coming from.
FIREM wrote:Cascade, if used must be flushed well. Agreed it may be slightly caustic but it cleans well, espically if the system was contaminated with oil.
No oil at all. If I had, I'd suspect something worse, like the head gasket.
FIREM wrote:Bill's back flush device will really clean out anything in the system for sure..
I'm going to try it, fingers crossed, if the Peak Performance Super Cleaner and Flush still leaves the rust residue behind. Easy enough to pull the upper radiator hose and look. Looking at the MSDS of it, though, it contains:

Water 63 - 64%
Ethylene Glycol 34 - 36%
Diethylene Glycol 0 - 2%
Denatonium Benzoate 30-50 ppm

I'm not especially impressed that this will do anything. Denatonium Benzoate is a chemical used to bitter the Ethylete Glycol so it doesn't taste sweet. It's also used to denature alcohol. The Diethylene Glycol is "present as an inadvertent byproduct of ethylene glycol production." (Wikipedia)

To say I'm disappointed would be an understatement. I now have no faith this will do anything to clean and flush the rust sediment out. It's basically worthless junk. There's more cleaning chemicals in a splash of the old green Prestone (the sililcates, for one thing). I'm pretty sure I'm going to be building Bill's Blaster.

Edit: I checked the MSDS of Prestone ® Super Flush, 10-Minute Radiator Flush. It contains Sodium Citrate (5-15%) and water. Sodium Citrate is a sodium salt of citric acid, and citric acid is another one of those chemicals people have recommended to clean cooling systems (including Mercedes Benz). That is, Citric Acid is recommended by M-B. Not Sodium Citrate. Sodium Citrate is a food additive and alkalyzing agent. It will neutralize acids but won't do anything for oil, gunk or scale, and as I found, won't remove much of the rust, either.

After doing some digging, it looks like Permatex Heavy Duty Aluminum Radiator Flush is a serious flushing agent. The ingredients are:

Citric Acid 10-30% - an effective remover of rust and corrosion and scale - see above recommendation, including by M-B.
TetraSodium EDTA 5-15% - Chelating agent - dissolves scale and holds it in solution.
N-METHYL-2-PYRROLIDONE <5% - Solvent/degreaser, often used as a paint remover, it's especially effective at dissolving polymers/gums/gunk.
2-Butoxyethanol <5% - A solvent/degreaser - will remove grease & oil
POTASSIUM HYDROXIDE <5% - Raises pH and also dissolves oxides
Dodecylbenzenesulfonic acid <5% - A surfactant (wetting agent) - a primary ingredient in detergents

This, my friends, looks like a real cooling system cleaner! As a matter of fact, following up the Permatex with Prestone Super Flush to neutralize the remaining acid might not be a bad idea.
User avatar
 #287897  by Maximus
 
Again, are you sure your seeing rust and not a sludge. There should be no rust in this cars coolant system. It can't come from anything that large.
User avatar
 #287907  by mnitetrain
 
We have seen way premature failure on Bosch pumps, some as soon as a month after installation.
User avatar
 #287908  by Maximus
 
A bad pump is not going to produce rust unless the coolant was never ever changed and the wrong coolant was in there from day 1 I still dont think you would see any rust. It is probably a chemical compound that looks like rust, but I doubt it is rust.
User avatar
 #287920  by 300maximilien
 
Max...did you miss Arveds post about running plain water in the system for an extended time? That could cause rust....and very quickly at that!
User avatar
 #287926  by Maximus
 
Umm still don't get it. Has anyone else here ever seen rust in there m coolant ?
User avatar
 #287933  by 300maximilien
 
Maximus wrote:Umm still don't get it. Has anyone else here ever seen rust in there m coolant ?
Well think of it this way. Coolant doesn't just cool. It also keeps corrosion from happening. No/little Coolant = Rust/Corrosion. Steel can start rusting immediately once in contact with "fresh" water.
User avatar
 #287953  by miska_man
 
Maximus wrote:Umm still don't get it. Has anyone else here ever seen rust in there m coolant ?
Most around here only use distilled water.. hence having no rust in anyone else's system.
User avatar
 #288059  by grayslater
 
My question is are we basing a color to having rust or are we actually seeing sediment?
User avatar
 #288074  by Maximus
 
grayslater wrote:My question is are we basing a color to having rust or are we actually seeing sediment?
I'm kinda asking same question about the rust. I really don't think its rust but a result of something else.
User avatar
 #288139  by Arved
 
Maximus wrote:
grayslater wrote:My question is are we basing a color to having rust or are we actually seeing sediment?
I'm kinda asking same question about the rust. I really don't think its rust but a result of something else.
I could wipe the inside of the hose or the water inlet fitting, and have a fine reddish brown powder on my finger tips. This was absolutely clean otherwise. No slime or oily residue.

I finished a flush with the Permatex Aluminum Radiator Flush, and the system is now clean. When I open the upper radiator hose, there's no hint of the rust anymore. I'm satisfied the system is finally clean. I'm doing a distilled water flush, and then will add Zerex G-05.

I consider the Prestone and Peak flush chemicals to be worthless. Their lack of effectiveness is no surprise after reading the MSDS for these products. The Permatex product was effective, and comparing it's MSDS to the others, it's easy for me to see why.
User avatar
 #288141  by FIREM
 
Looks like we have found a winner ! Noted for future reference in KB Cooling Section
 #318879  by 300mguy
 
Where can Permatex Aluminum Radiator Flush be found? Amazon is out of stock. I bought Permatex Heavy Duty Radiator Flush (80030) but the bottle says it is not recommended for aluminum systems. Did they stop making it?