WATER PUMP LONG OR SHORT - Someone please help

[Rolf-Dieter ✝︎]

Hi Everyone,

Can one of you help me with this question?

My fan blades failed this weekend due to I believe the mounting plate for the pump inside the fan cracked due to overtightening. I am purchasing a new water pump. Can you tell me when the Long was changed with the short pump I assume the difference is the shaft length?

My VIN Nr is 11304412007259

The question is, what pump type would have been used for my 1969 (left assembly line Dec. 1968), 280 SL with above VIN (SN)?

Thanks in Advance!

Dieter

[66andBlue]

Hello Dieter,
unfortunately your VIN does not help here because in the spare parts list (10180) changes are indicated by engine number.
 
There are three versions listed for the 280SL (M130/983) : p/n 121 200 0820, 121 200 0920, and 115 200 0020. The first one (xx0820) was also installed in the 250SL.
I do not know which one of these is "short" or "long". In addition I do not understand the footnotes associated with these part numbers.
Apparently the early p/n (xx0820) was installed starting with engine #000433, whereas the replacement (later?) was in engines up to #000432 (engines in cars with manual transmission).

Perhaps someone else can figure this out.

[stickandrudderman]

You just need to measure the length of your old one.
There are three pumps: 50, 70 and 90mm.

[WRe]

Hi,
afaik the 280 SL has two different water pumps:
- A110 200 1020 replaced by A110 200 2020 (62mm)
- A110 200 1720 (92mm).
https://www.niemoeller.de/de/w113/w113/B044/206/1
Maybe there is some difference with US models and AC.
...WRe

[Pawel66]

I do not suppose EPC is helpful here. It does not specify the lengths, I think.

For 113044 (US) I see:


A 115 200 15 20 Water Pump, replaced with
A 115 200 18 20 Bearing housing, supplied as reconditioned, foot note: As of engine: 980 10/50,20/60 005239 980 12/52,22/62 009386 981 10/50,20/60 000105 981 12/52,22/62 000829 984 10/50,20/60 000100 984 12/52,22/62 000047 (no 983 mentioned...)

Then
A 110 200 09 20 Water pump, replaced by
A 110 200 17 20 TS Water Pump, RANGE OF DELIVERY; TO BE USED AS A NEW PART ONLY, but then footnote says PART IS ONLY OR ALSO SUPPLIED AS RECONDITIONED PART and another foot note: As of engine: 980 10/50,20/60 005239 980 12/52,22/62 009386 981 10/50,20/60 000105 981 12/52,22/62 000829 984 10/50,20/60 000100 984 12/52,22/62 000047
 and it is replaced with
A 110 200 17 20 80 TS Water Pump

And it is available, around $250.

I remember from previous threads on this topic that the best is, as stickandrudderman says - measure and order what you have.

[stickandrudderman]

90mm 4 hole: A110 200 17 20
90mm 3 hole: A115 200 16 20
70mm 4 hole: A110 200 02 20
50mm (?)       A110 200 20 20

[Rolf-Dieter ✝︎]

Thank you everyone !

The pump removed (without the mounting plate - The mounting plate is still in the fan center) was reported to be approx. 3 inch in length.

Also (see photo 1 mounting plate has 4 screws).

I provided photo 2 to my mechanic hand he confirmed that my pump removed from my car is the one on the left.

So I must assume the one that Dave will ship to me is the short type and the correct type.

Thanks again everyone.

Dieter

[ja17]

Many owners replace the short pump with the long one. With the long one, the aluminum spacer can be deleted all together. The original four long mounting bolts then must be replaced with the short bolts, typically used on the long water pumps. The conversion makes installation much easier and the bearing spacing in the long water pump has lower bearing loads. 

[mdsalemi]

Rolf-Dieter,

As you know our cars are closely related brothers, produced in the same week, maybe the same day, and differ by just 3 in VIN...

In 2011 I changed my water pump, and based upon the recommendations of Joe Alexander JA17, I changed from the short pump to the long pump.

Dave Gallon supplied me with what I needed. He gave me three choices: OEM in the MB box, a Febi, and a Laso. David recommended the Laso. That's what I put in. He also sent the required short bolts, and I sent the longer bolts back to him. Joe recommended an OEM gasket; the ones that come with the Febi and Laso are really paper thin, but the OEM gasket has some substance to it.

[Rolf-Dieter ✝︎]

Thank you Joe and Mike for this information. I am in contact with the Vendor if my parts shipment has left or not.

Thanks again!

Dieter

[Rolf-Dieter ✝︎]

I still like to know why there is a short and long water pump.

I know we have a listing somewhere in our Technical Manual that details when items have been changed, improved, etc, on our cars. I just cannot find it. I would think it must also include the water pump.

At this point, I can only assume that Joe Alexander touched on it from a design and bearing loading point that the long pump is the better one and therefore I assume the long one replaced the short one?

Does anyone have that listing of changes that have taken place over the years?

Dieter

[mdsalemi]

I still like to know why there is a short and long water pump.

That question may go far beyond our cars. I mean, if you think about it: there were less than 50,000 units made over a nine year period, that ended nearly half a century ago. Yet, when I went looking for water pumps, there were THREE brands available to me. That tells me that the basic pump design was used a many different cars...

[WRe]

Hi,
the listing of changes (as listed in Engelen) shows 555 changes during the whole production time: 448 - 230, 33 - 250, 74 - 280.
Changes of the water pump are listed in 09/63, 08/64 and 10/65 only.
I would assume that in conjunction with installation of an air condition, change of a 6-blad to 8-blad fan and installation of a fan shroud this change could have happened.
If you currently look for new water pumps you can find 15 different brands (w/o MB) only here in Germany: https://www.daparto.de/Wasserpumpe/Mercedes-Benz-SL-Pagode-W113/2-1211-775?kbaTypeId=931.
These water pumps have been used in many different cars of MB, e.g. R107, W108, 111, 114, 115, 116, 123, etc. .
...WRe

[mauro12]

I’ve just replaced the water pump and thermostat in my 250sl and it has the short pump. The 280 has the long pump ,Im almost sure.

[mauro12]

This is my new short pump . If I had to put the long pump, I’m sure it would have been more difficult .

[mdsalemi]

If I had to put the long pump, I’m sure it would have been more difficult .

No difference in difficulty.

[Atazman]

I'm puzzled by the thought of easily changing from short to long pump.  Seems to me that you would have to move other pulleys closer to the radiator for belt alignment?  I admit, I have not looked under my hood to sort this out on my own.

[Rolf-Dieter ✝︎]

It would seem to me that having a shorter hub On the water pump would be much more stable on the bearing and housing as there would be less leverage working against it under the axial load of the belt tension. Once I had confirmed that my original water pump was the short type, my decision was to stick with the shorter hub pump.

Dieter

[mdsalemi]

I'm puzzled by the thought of easily changing from short to long pump.  Seems to me that you would have to move other pulleys closer to the radiator for belt alignment?  I admit, I have not looked under my hood to sort this out on my own.

When you use the short pump, you must use an aluminum spacer on the end of the pump. What that spacer does is bring the pulley you mount on the pump end into perfect alignment with the belt path. The long pump does not need the spacer, it's all aligned.

While these questions are all interesting, it's not nearly as challenging as it may seem. The pumps are interchangeable. With the short pump you need long bolts, and a spacer. With the long pump you need short bolts. These bolts are to attach the pulley.

[Atazman]

You "unconfused" me, Michael!  Thank you.  And, yes, my car looks like I have the spacer; I know I have a short pump.  Hard to tell it is a spacer with the hood in place.

I had seen the spacer on the long pump in the picture early in this thread.

[ja17]

I have always found the long water pump much easier to install, it has less parts to align (no spacer).

[mauro12]

The most difficult part for me was to put the hood back. Please be carefull with the water pump bolts. They are rusty and they break very easily if you force them. I soaked with wd40 . The same thing with thermostat bolts. Another advice, do the entire process with the radiator on. It will be a bit more difficult to put the vent on, but I’m sure you save a lot of time and effort.

[Rolf-Dieter ✝︎]

Hi Joe, I do agree, less parts results in easier assembly. I was pressed for time to get the parts on the road. Mike pointed out 4 different pups. So I decided to stay with the original design. Thanks for your input Joe! Dieter

Mauro, good advise, I passed it on to my mechanic. On the hood, we disturbed only one side of the fasteners in order not to destruction the perfect hood alignment. We do hope the water Pump bolts don’t present any issues, hate to drill them out. Thanks for your input!  Dieter

[mdsalemi]

When I did this a few years ago, it was because Joe Alexander noticed that my water pump, the old short one, was exhibiting a very slight leak. So I took the opportunity to change the pump and while I was at it have the radiator re-cored (from SL Tech), and refinish the shroud, the fan blade, and the air cleaner canister. I followed all of Joe’s suggestions and did this with the car on ramps. I did all the work myself. I can say it was relatively easy although a bit challenging at times. As I recall there were a few bolts that were a little difficult to get to. But I dropped the radiator out the bottom of the car and I did not dare remove the hood and it was not necessary to do so.

I do not have nearly the tools nor the workspace that so many of you do and yeah I did this all in relatively short order so anybody can do it.

[thelews]

I replaced my short pump last year when the seals failed on my 250 SL.  I removed the battery and tray, air cleaner and radiator (from below) to do it.  There's some fiddling and dicking around, even the battery and air cleaner become a little project with things being tight.  Make sure to protect the radiator from damage.  But, it all went together fine with no leaks.