Coolant Expansion Tank - what inside the new version?

[Christian_K]

Hi, so i replaced my old n ugly Overflow Reservoir for the engine coolant. And i noticed that there is some sort of a filter in it thats filled with something sand alike. I asked Bernard if that normal and he said NO thats not normal. But Part Nr is the right one.

See the pic please after arrival:


So i put it in the car yesterday and i was quite happy after install. Also i could see from outside from a distance now how full the overflow tank is, since its a bit transpartent and my coolant (Glysantin G30 Alu Protect) is pink in color. Yes right. So i was bleeding the car yesterday some longer minutes and stoppped it.
Today i opened the hood and noticed immediately that my coolant was not pink anymore but grey-ish colored. Also there was some slight pressure inside the reservoir.

The collant looks like there was charcoal inside this little filter that sits inside my new reservoir or so. Whats your opinion on it?
Pics from today:

 

[gsxr]

Re: Coolant Overflow Reservoir - what inside the new version?

Christian, that is a silica pack that helps control corrosion. I thought the originals had it as well, but maybe not? No idea if the G30 coolant plays nicely with it...

 

[Klink]

Re: Coolant Overflow Reservoir - what inside the new version?

No idea if the G30 coolant plays nicely with it...

I am guessing, but it is only a guess, that this newer coolant chemistry is not compatible with the chemical packet in the expansion tank, and/or remnants of the old coolant. Our newer cars are arriving with a pink coolant, and IIRC, it is absolutely not compatible with any previous coolant, which also suggests that it may not be compatible with any supplement packet placed in the expansion tanks of earlier models.

 

[Rouven036]

Re: Coolant Overflow Reservoir - what inside the new version?

Klink you are right about the coolant. There is a Service Information which says that it is normal that the new coolant type will change colour if mixed with the older coolant type. Technically no problem except the look. The complete coolant system must be drained and flushed thoroughly before refilling it with the new coolant type in order to avoid this to happen. So block and heater system must be drained and flushed. The flushing can be done by several times draining and refilling the system with normal water. Block must be drained each time too. The silica bag is normal, comes in all newer models and containers.

 

[Klink]

Re: Coolant Overflow Reservoir - what inside the new version?

Klink you are right about the coolant. There is a Service Information which says that it is normal that the new coolant type will change colour if mixed with the older coolant type. Technically no problem except the look. The complete coolant system must be drained and flushed thoroughly before refilling it with the new coolant type in order to avoid this to happen. So block and heater system must be drained and flushed. The flushing can be done by several times draining and refilling the system with normal water. Block must be drained each time too. The silica bag is normal, comes in all newer models and containers.

Thanks. I will have to double check, but I recall seeing no such bulletin here in the USA. That would not be unusual, as there is often a lag time, and sometimes an outright omission of bulletins that they don't consider relevant to us here in Yank.

I'll see what I can figure out, but our current hearsay/training here is that we can use the pink MB coolant in cars that were delivered with it, and that we must use the older formulations in all of the previous cars. The information you have may indeed be newer. It is also possible that our USA minders consider the discoloration unacceptable in our ridiculously fussy and fright prone market ...

 

[Klink]

Re: Coolant Overflow Reservoir - what inside the new version?

Oh, while we were on the topic let's get our American/English terminology straight: The under hood mounted tank with the filler cap is more properly referred to as the "expansion tank" The reservoir mounted in the inner fender that would actually catch coolant being emitted from the expansion tank is the unit more properly referred to as the "overflow" tank.

Does this correspond with any of the more common German terms for these devices? Just curious ...

 

[Christian_K]

Re: Coolant Overflow Reservoir - what inside the new version?

Hmm... i use this: http://www.glysantin.de/en/products/g30.html
No my stock tank did not have that Silica pack inside. So that silica inside the reservoir is coloring my fluid?
Maybe it reacts with the organic corrosion inhibitors? I actually dont want to switch from G30 to anything else, as it is recommend for M119 engines with starting aluminum corrosion. Mercedes did sold it under the name "Type 30" and on my stock reservoir that was a little sticker which showed "Only fill in Type 30 coolant". Mercedes Type 30 is Glysantin G30.

 

[Klink]

Re: Coolant Overflow Reservoir - what inside the new version?

The corrosion inhibitor package started being added to the tanks early to mid 90s. I think actually closer to the mid 90s. IIRC, it was first brought to our attention here in 1994 with the introduction of the four valve diesel engines for what was the 1995 USA model year. We had no idea that it was phasing into other models until many years later when a few of them came apart and plugged up some heater cores, etc.

I will try to learn a little more about this compatibility/discoloration question when I get the chance. This kind of thing is going to happen here for sure, and somebody is going to freak out about it, likely unnecessarily.

Some additional uncertainty is added to the discussion because MBUSA has its own coolants formulated here and identified simply by a "BQ" part number with little to no other description of its chemistry. We know that our yellow is essentially G05, and that the blue is compatible with it. I need to do a little additional research on the pink...

 

[Christian_K]

Re: Coolant Overflow Reservoir - what inside the new version?

Hi, MB recommends for our M119 engines a coolant after MB-Sheet 325.0. Thats for instance Glysantin G48 (Color old: Green, Color New: Blue-Green). But when there is starting aluminum corrosion, a complete flush and fill-in of "Coolant Type 30" after MB-Sheet 325.3 was recommend and written in the WIS IIRC, with the advice to add that stick to the reservoir and/or the filler cap. My car had that sticker. So i sticked with that fluid and i was used to having a reddish/purple/pink colored antifreeze in my car.
But now with the new reservoir it changed color after one day.

By the way, the term in german for these things is "Ausgleichsbehälter". Its two words in one. "Ausgleich" und "Behälter". Ausgleich means "balance/equation/compensation/leveling", Behälter means "container/case/tank/repository/etc".
So i also think its more Reservoir than overflow tank. A Mod is free to change the title of this topic. Thank you all

 

[Rouven036]

The issue you have got was the result of old coolant remaining in your system. It's only related to the color the coolant had.
The SI bulletin says you can use the new mb coolant in all older models without problems (except the flushing) but you should not use the old type coolant in the new engines which came with the pink coolant. Klink if you want I can send you the bulletin tomorrow for your reference...
The correct english terminology is expansion tank and overflow reservoir. Expansion is here related to the german "Ausgleich-, ausdehnen"

P. S. The new pink Daimler G40 should be better in terms of corrosion protection as the previously used g30 and derivatives

 

[Klink]

The issue you have got was the result of old coolant remaining in your system. It's only related to the color the coolant had.
The SI bulletin says you can use the new mb coolant in all older models without problems (except the flushing) but you should not use the old type coolant in the new engines which came with the pink coolant. Klink if you want I can send you the bulletin tomorrow for your reference...
The correct english terminology is expansion tank and overflow reservoir. Expansion is here related to the german "Ausgleich-, ausdehnen"

Thanks! I would appreciate you sending on the info. That will save me a little research. That I do not already know about this is inexcusable on my, and/or possibly someone else's part...

 

[gerryvz]

possibly someone else's part...

Uncle Kent's ?!?

 

[Christian_K]

Rouven, i did not say i changed coolant. What i did was i switched the Expansion Reservoir. Not More not less.

 

[Klink]

Thanks! I would appreciate you sending on the info. That will save me a little research. That I do not already know about this is inexcusable on my, and/or possibly someone else's part...

Uncle Kent's ?!?

Yes! That's the guy!

 

[Rouven036]

Eh that guy looks like series killer in an mb suit

 

[Rouven036]

I did some more research today: the silica pack was introduced from 07/92 onwards to improve corrosion protection.
Further in regards to the three different available coolants:
G48 blue/green, sheet 325.0 A0009890825 (pure) /326.0 (ready mixed), silica based coolant.
G40 red (new) sheet 325.6 A0009892825 (pure) / 326.6 (ready mixed), silica based coolant. Cooling system must be thoroughly flushed due to colouring issue (brownish/greyish) if mixed with other coloured coolants. Coolant live time 15years/250000km or as stated in the vehicle maintenance manual.
G30 color? Sheet 325.3 A0009891625(14) (pure), organic nitride based coolant. For engines with alloy corrosion damages. Not suitable to mix with any other coolant. Must be changed every 3 years. If it is used once, a change back to silica based coolant is not permitted. Warning sticker has to be put on coolant expansion tank!

The other documents I can attach tomorrow

 

[Christian_K]

Everything nice and so forth..
Still no one can explain why my coolant changed color after i changed the reservoir? I've done nothing to the coolant itself. Its still the same one.

 

[Rouven036]

The silica bag in your new expansion tank might not work well with the G30. The G30 is based on nitrides and the engine should not be filled with anything else than that if used only once. Since the standard coolants are silica based and the bag is filled with silica this might be the reason.

 

[nocfn]

I gathered from reading this (assumption) that the silica bag inside your new reservoir contained a dye and when cycled at high temps thru your system, the color changed.

 

[Christian_K]

Just for an update: The reason for the discoloration was that the system created a vacuum and sucked green old coolant from the overflow tank that sits inside the front right fender. I started notice some green liquid and tested this further, by sucking some of it out with a vacuum-hand pump. See pics.



But i have a new problem with pressures in my system since i changed this tank. I found the old tank had a crack close to the cap area so it was never pressurized i belive.
I'll open a topic about it now, will take some time to translate it all proper and list it step by step as i already lost my mind with that stuff.

 

[Marc R]

Christian, do you happen to have a part number of the new overflow tank?
i'd like to change mine too

 

[lowman]

Re: Coolant Overflow Reservoir - what inside the new version?

Hmm... i use this: http://www.glysantin.de/en/products/g30.html
No my stock tank did not have that Silica pack inside. So that silica inside the reservoir is coloring my fluid?

Did you not take out that silica pack?thats only to keep mosture out of the packaging for the New part when in store.
it is NOT to be put in the tank when filled up With fluid.

 

[sheward]

Here you are, Marc. 124 500 1549

drew

 

[Marc R]

Thanks Drew!