Coolant Expansion Tank

[A Dalton]

Tom
 Actually, I agree with you that I doubt they ever went from plastic
back to brass.
 My thoughts are once the plastic got to the production line, they all got plastic..and continued to get palstic. So, if one had a brass after that point in time, it got there as yours did  [ which I also think is a better idea/tank.]
 I just think they did not get a plastic tank as archieves dates suggest, but rather they got them when the supply of brass tanks on the line were used up...rather than a specific date...
 .. but . maybe not....
 I prefer to see a brass tank on ANY 113, no matter what year is was made..............

[Tom]

Arthur,

Seems logical that they would use up all old stock and then use the new specification.  After all, in the case of the tank, it was likely a cost saving move and only makes since to use the remaining old stock before using the new stock.

On a slightly related topic, decals changed over time and are often in different locations.  Further, paint colors for torque marks on bolts were not applied uniformly in terms of color.  I think we (especially me) often think that there was more consistency than actually existed.  Cars built on the same day might be very similar-even identical.  A month later could be a different story.

Hearing from an original owner carries a lot of weight with me and I instantly defer to what that owner says as being the definitive word on what is original.  But unless that owner was the only person to service the car over the last 35 years, they have lost the chain of custody over the car and can't be 100% certain in all cases that a part, wiring arrangement, hose clamp, etc. is true to the car.

Perhaps this is a partial explanation to the original owner mystery.

Best,

Tom

1971 280sl Tunis Beige Metallic (restored & enhanced)
1971 280sl Tobacco Brown (low mileage stock)
1970 280sl Deep Red (Project Car)

[norton]

Is a plastic tank interchangeable with a brass tank, with out any mods?

[tobacco]

My one-owner '71 280 SL (built 11/70) was delivered with a brass coolant expansion tank.


Bill Greffin
Chicago
#22375

[Ed Cave]

I think we might be on to something. Bill Greffin's production number suggests a November 1970 build and he states his one owner was originally delivered with a brass tank. That makes all three 11/70 cars referenced in this thread as brass tank cars.

Both 9/70 builds (mine and Ken G's) in this post are plastic. Now I agree our control sample size is limited but it has to get you wondering. And surely no one would switch out a brass one for plastic???

Personally, I think they thought they had installed the last brass one, switched to plastic, then stumbled across a big 'ol box of misplaced brass ones and figured, "Why waste 'em?".[:0]

It also starts to border on just how much it really matters.




Ed Cave
Atlanta, GA

1964 356C
1971 280SL
2002 SC430
2004 A4 3.0

[norton]

I think we should start a sub group for brass tank 11/70 cars  

[Ben]

And just to add absolutely nothing of any use to the conversation my 230SL has the indentical stress fractures that were mentioned !

Q. Are the part numbers for these Plastic & Brass tanks actually both 113 numbers, or was one also used elsewhere ?

Regards,
Ben in Ireland.
'64 230SL 4sp.

[Jonny B]

Edition C of the 250SL-280SL parts book lists only one number for the expansion tank, 109 500 00 49, which indicates it is not a unique piece for the 113 cars. There is no mention of plastic or metal.

Jonny B
1967 250SL Auto

[Benz Dr.]

I have a 1970 here and it has the plastic tank and it's an original car.
 These tanks were also used on 108 280SE sedans.

Daniel G Caron

[glennard]

Originally posted by Mike Hughes

I'd like to hijack this thread to ask about what seems to be a common stress crack that occurs in the same place on just about every 230SL round, flat style tank that I have seen.  It appears on the top edge of the tank body adjacent to but below the raised square section where a label was placed and is usually about 1/4 inch long, parallel to the raised edge of the square section.  Looking at the tank from the front this would be at about six o'clock.  I have had both of the tanks that I own repaired (soldered - they're afraid to braize there to avoid warping the tank!) at least twice and the repair only lasts for a few hundred miles.  Any ideas?

- Mike Hughes  -ô¿ô-

  1966 230SL Auto P/S
  Havanna Brown (408)
  Light Beige (181)
  Cream M-B Tex (121)


Have a '64 with broken support, but no leak.  Is this common too?

[mdsalemi]

Hi Ed,

My tank (built 1/69) is the black-painted brass one--but HDPE or LDPE plastic tanks are probably the same material as the brake fluid reservoirs.  If so, unlikely to restore it.  The plastic changes over time with heat and with the fluid containment.  It also "outgasses" the plasticizers that add some resiliancy to the material--which leads to cracks at stress points.  I don't believe anyone has found anything that will bring this plastic back to it like-new white condition.  Tom Sargeant of our group even soaked his brake fluid tank in a chlorine solution for many months with no apparent change in color.

I can't help you on the next three questions--it seems as if you have done your homework and found that YES a new tank is available and NO it isn't reasonable in price, and PROBABLY the one part number has been changed to plastic.  There are many parts I have bought over the past few years from MB that are only available in the latest style and in some cases this isn't correct.  For example, the auto transmission filler/dipstick tube WAS yellow CAD plated, now painted black.  Brake fluid reservoir WAS straight, NOW sits at an angle. Brake booster vacuum line WAS fitted with a black check valve, now white.  Fuel expansion tank WAS with brass fittings, now all plastic.  It goes on and on...  Mercedes is more concerned with providing a working part then with pristine correctness.

If $500+ is the target price, perhaps you could investigate having this tank fabricated in brass; you'd need someone with a "donor tank" to lend you.  Here's a few places from my research list to start:

http://www.ifmetalworks.com/  Custom Brass Fabrication
http://www.allradiator.com/    Supplier of Radiator Parts--might point you to a fabricator of brass tanks
http://www.macsradiator.com/index.asp  Custom/Vintage Radiator Fab
http://www.calwest-radiators.com/default.html  Custom/Vintage Fab

Hope this helps.  I don't know if the older brass tank crossed over to other MB models--it probably did--and in that case there are probably a lot of old sedans out there rusting in the fields (you who have the fields of them know who you are  that have a tank you could purchase OR at least one you could borrow for fab purposes.


Michael Salemi
1969 280SL
Signal Red w/Black Leather
Restored

[Ed Cave]

Michael:

Thanks for a good, comprehensive response. I may have misled you; it is the 'correct' plastic replacement that is $556, not the brass one. As far as I can tell neither are available from anyone other than MB. Spending that kind of money on a new plastic one that will undoubtedly discolor over time seems foolish.

And although I am not in the 'Wanted to Buy' forum, rather than start this whole topic over, I will stick my neck out just this one time and ask:

Does anyone have a good restorable brass coolant tank that they are interested in selling?

No need to respond here, just email me instead, please. Thanks very much.

edcave@bellsouth.net

Ed Cave
Atlanta, GA

1964 356C
1971 280SL
2002 SC430
2004 A4 3.0

[Ben]

quote:Have a '64 with broken support, but no leak. Is this common too?

......well my '64 has a broken front support too but again no leak ! Its the support nearer the front !

Regards,
Ben in Ireland.
'64 230SL 4sp.

[Naj ✝︎]

Ed,
I've been studying your tank picture (as one does  :oops:  ).
That white painted dot below the wiper motor mounting plate - should it not be a black rubber plug?
Bit off topic, sorry.
naj

65 230SL
68 280SL

[Tom]

Here is the answer from Gernold on the expansion tank:

The plastic tank was installed from 8-21-70 to 11-16-70 VIN 20458 to 22306 per Engelen Book.  All later cars had the Brass tank.  Apparently the plastic tank was a trial run to study the plastic tank issue and when the initial production run was exhausted they did not want to make any more because the 113 chassis was already planned to be stopped.  The brass tank stock was then used up to the end of production.

Best,

Tom


1971 280sl Tunis Beige Metallic (restored & enhanced)
1971 280sl Tobacco Brown (low mileage stock)
1970 280sl Deep Red (Project Car)

[Ed Cave]

Tom:

Thanks for connecting with Gernold to confirm my suspicion that the tanks were brass, became plastic and then became brass again. I was beginning to question my own sanity.

Even before reading your post I had pretty much decided to keep the original plastic tank in the car. The more I looked at it the more I began to appreciate the patina it has attained over the past 34+ years.  The coolant tank (photo in original post on this subject) has a very consistent color to it that is really quite different than the typical yellowing of the other smaller fluid containers in the engine bay and the more I've looked at it the more I've come to actually like the way it looks

Now that I realize how rare the plastic coolant tank is I am confident that my decision to keep it is well founded.

Isn't it great how something can go from an eyesore to a rich patina in the length of one thread!

Ed Cave
Atlanta, GA

1964 356C
1971 280SL
2002 SC430
2004 A4 3.0

[erickmarciano]

there you go

[Mike Hughes]

If you are referring to the vertical support post that bolts to a bracket under the tank, this bracket can easily vibrate loose from the tank.  This seems to be common.  The bracket just needs to be soldered back in place.

quote:Originally posted by Ben

quote:Have a '64 with broken support, but no leak. Is this common too?

......well my '64 has a broken front support too but again no leak ! Its the support nearer the front !

Regards,
Ben in Ireland.
'64 230SL 4sp.

- Mike Hughes  -ô¿ô-
  1966 230SL Auto P/S
  Havanna Brown (408)
  Light Beige (181)
  Cream M-B Tex (121)

[Tom]

Ed,

Do you have the part number for that plastic tank?

Thanks,

Tom

1971 280sl Tunis Beige Metallic (restored & enhanced)
1971 280sl Tobacco Brown (low mileage stock)
1970 280sl Deep Red (Project Car)

[Ben]

quote:If you are referring to the vertical support post that bolts to a bracket under the tank, this bracket can easily vibrate loose from the tank. This seems to be common. The bracket just needs to be soldered back in place.

....yes Mike thats the one.......and thats how I repaired it !

Regards,
Ben in Ireland.
'64 230SL 4sp.

[awolff280sl]

I was very impressed brass expansion tank in the picture posted by pbossel. After removing the black paint, how do you go about making it look like that?

[bpossel]

Hello Andy,

When I bought my 113 a few years ago, the tank was peeling and looked ugly.  To make my brass tank shine, I removed it and used a brass wire wheel on my bench grinder.  I then used some metal polish and manually polished it with some rags.  When I could see my reflection, I stopped....  scared myself[:0]!

Now I am in the process of having the black paint put back on the tank to bring it back to its original finish...

Bob

bpossel  (Memphis, TN.)
'71 280SL  /  '97 E320

[Raymond]

Every time I see an unpainted brass tank, it makes me cringe.  I have never said anything because it makes the owner happy and it's their car.  But to me, it sticks out like a sore thumb and detracts from the look under the hood.  When I rebuilt my engine, I stripped and polished the tank and it struck me like bling on a mini-van.  So I painted it.  

To each his own, but the shiny brass doesn't appear anywhere else on the car and it won't stay shiny for too many years.

If the plastic really offends your visual sensibilities, there are special plastic paints that could render it black.  I painted the plastic instrument panel in an airplane and it still looked new 10 years later.


Ray
'68 280SL 4-spd Coupe