In the past, “Restoration” articles have always been more general, as I recorded them briefly in a bookkeeping-like manner. Because there are so many tasks that cannot be described in simple words, writing them all down would take more time than doing them. But thereis an exception today. I am willing to spend 3 hours to record how a subsystem of this huge project is properly recoverd.
The Source
In 2014 I got the book “Die Mercedes S-Klasse”, a very detailed literature about the 140 by Eberhard Seifert from 1991. There are tons of interesting facts, including an interview with Niki Lauda. This article is a reprint from the September 1991 issue of the Austrian automotive journal “auto revue”.
Niki Lauda is one of the first Austrian owners of the 140, on the cover is him and his 600 SE. This is already his second 140, the first is a 500 SEL that he ordered at Geneva Salon in March 1991. photo: auto revue
Niki Lauda was infatuated with that car and had many nice words to say about it in his article. Coming from a former F1 driver, this is remarkable. But I was a little confused when I read one of the passages where he said:
Erstens einmal spüre ich ein angenehmes Kribbeln, wenn ich den Motorraum aufmache. Diese souveräne Aufgeräumtheit ist einfach toll. Da es nur geschlossene Einheiten und keinen einzigen Punkt zum Fummeln gibt, bekommst du erstens die Message: Da wird nichts kaputt. Und zweitens: Wenn doch, dann brauchst du gar nicht erst hinzugreifen. Lieb finde ich das Schauglas für den Wasserstand der Scheibenwaschanlage; das ist sozusagen das einzige, das ein Außenstehender kapiert. Alles andere ist abgeschottete Hi-Tech.
The underlined sentence translated into English is: I like the sight glass for the water level in the windshield washer system; That’s sort of the only thing that an outsider understands. Everything else is isolated Hi-Tech. I was confused, what is the so-called sight glass that favored by Niki? I have never seen this thing on the 140. Shouldn’t the level of windshield washer be displayed as a warning light on the instrument cluster? Since this article only reposted one picture, I thought it may have missed photos from this section, so I tracked down the original copy. Sadly, the original copy doesn’t have this detail either, and I still have no idea what Niki Lauda was referring to.
Thanks to auction websites like Bring A Trailer that can post a lot of high-resolution photos, I finally found this part one day.
You see, it’s like a periscope with a float on it. The major component is a transparent plastic tube with a scale of 2-5 on the tube and a red float inside. It uses the principle of the same liquid level on both sides of the U-shaped tube to connect the bottom of the indicator to the bottom of the reservoir. The height of the reservoir liquid level will also be passed to the sight glass, so you can see how much liquid is still in the reservoir. This sight glass is fixed on the passenger side of the radiator.
The System
Why is this sight glass so rare on 140? According to the EPC, it only applies to cars before A204157, which is slightly less than half of the total 140 production. Octavius is A149549, but this part was not with the car when I acquired it. I would definitely like to have such quirky design restored if he should have. The above picture belong to A203382, a 1995 S 420. It’s one of the last 140 with such sight glass.
What’s interesting about this part is that since it’s part of the system, it should naturally connect to other parts. For example, where is it mounted on the radiator? How is it connected to the reservoir? I checked several cars around me and couldn’t find any answer. So I decided to get the reservoir and its clamps first to see if it could be mounted there.
I purchased a NOS sight glass and two clamps and tried to follow Bring A Trailer’s photos to find where to mount the radiator. I didn’t find any, it looks like the side cover of the radiator must have 2 brackets connected to the clamps. Well, that means different radiators. But there is only one radiator part number A1405001003 in the EPC.
At the same time, I did not find a hole on the reservoir to connect to the sight glass hose. According to the principle of liquid level, this hole must be located at the bottom, but several of my cars have no such holes, and there is not even a trace of modified molds.
The EPC gives 2 part numbers, A1408600160 and the one that replaced it, A1408600260. There is no description to what period the replacement occurs.
After some searching for old parts, the complete system should include:
1.Washer level sight glass (in our stock)
2.Radiator with brake on side (not in our stock)
3.Reservior with hole in the bottom (not in our stock)
Well, since it disappeared after A204157, that should make sense. Why do we need an additional in-cabin sight glass to view the level? The instrument panel can only tell you when the fluid level is too low: it is already too low, but it is too late! If you’re planning on toasting others with a whole can of windshield washer tonight, you’re screwed! This sight glass is a good way to tell you how much reserve you have left, if you always open the hood to check.
From today’s perspective, it’s really not very practical. However, as a pre-A204157 car, Octavius definitely used to have this system, it just had to go away due to limited parts supply. This system is actually very fragile. If you have to replace the radiator, the new radiator does not have the bracket to install the sight glass, and you have to remove the sight glass. The reservoir should also be changed at the same time, otherwise the washer will leak from the hole at bottom. On the other hand, if your reservoir is cracked and the new reservoir has no connection holes, the sight glass becomes useless and can be removed. So after 30 years, there are very few intact systems left that can survive.
I had to bring this system back for authenticity.
The Search
I already have the NOS sight glass and clamps, which is a good start. However, the reservoir and radiator are discontinued parts. Not to mention new ones, even used parts that can be reused are very rare.
These parts should be looked for on early cars that are in better condition and don’t have frontal collisions. Since the sight glass is only installed to A204157, the reservoir and radiator are probably also there. For the reservoir, it applies to all 140 models, so the probability of finding it is greater. As for the radiator, it’s V12 exclusive, so it’s harder to get, with the V12 only making up about 1/10 of the total production of the first 200,000 cars.
It didn’t take me long to find two correct reservoirs, one with cracks and one intact. You can see the difference between older (right) and the newer (left) designs: the old part has a larger volume and has a connection hole at the bottom. Of course, it looked to be in very poor condition (when the picture below was photographed, it’s already been partially restored), the bracket was completely rusted and the tank was yellowed. However, this is a less demanding part, as it is just windshield washer fluid, there is no undue heat or pressure, just make sure there are no visible leaks. Just some exterior work will be needed later.
Radiator is a real headache. Should used parts be used? It all depends on what we can find. If it doesn’t look too bad, I can just install it since the Octavius won’t be thrown into heavy traffic driving. Worst case scenario, I could remove the side cover from the old part and transplant it to Octavius’ current radiator. The current radiator of Octavius is a genuine part. Changing it is somewhat risky, but it can also ensure future use.
After 18 months of searching, I don’t even have the worst results. There are very few V12s that still have the original radiator, seems they all have somewhat experienced overheating issues that must replace the radiator. The closest chance I got was when I paid correct old radiator according to the photos seller sent me but then received a radiator that not only fit , . But in the meantime I acquired a 6-cylinder radiator with a bracket to see if it was possible to combine it with a V12 radiator.
The Solution
With Octavius’s restoration coming to an end, it is time to install the cooling system. Must make a choice, install sight glass or not? I looked at the sight glass and it would be a shame not to install it. Authenticity has always been the ultimate goal we have pursued in the past. Do we have to stand by and continue watching in next few years?
Shortly after I got the reservoir, I had it restored. The steel bracket was badly corroded and it was of poor quality. Because I installed a new reservoir in 2016, and after all these years of careful care and 16,000 km, the new bracket was completely rusty. First remove the rivets on the bracket and disassemble the bracket. Rust removed, galvanized, passivated to blue-white. It’s really easy for water from car washes to accumulate here, so it seems like a zinc coating was sprayed on as a further step. Ordered 2 genuine rivets and reassembled.
As for the tank itself, it is made from some kind of recycled materials and has a rough and porous surface that absorbs a lot of dirt and rust that cannot be pulled out. I sanded the surface quite a bit to remove all the dirt, and then used commercial plastic bleach to turn it from yellow to white. The effect is obvious and the results I get are not much different from NOS.
Radiator is another story. To ensure reliability, I decided not to wait for used parts but to install the bracket onto the existing BEHR radiator, which is almost new. The plan is to cut the bracket from the 6 cylinder radiator and glue it to the existing radiator side cover.
I sawed off the bracket from the 6-cylinder, cutting off as much of it as I could. However they cannot be mounted directly on the side covers because the curvature is very sensitive. After positioning the installation position, repeatedly polish the bracket to a more suitable arc until it can be seamlessly connected to the side cover. Then use UV glue to bond them. I heard the glue can withstand higher temperatures, but the radiator does get very hot, so we’ll keep watching.
By the way, I tried my best to correct all the crooked fins on raditor. This may seem inconspicuous, but it took 5 hours. The V12’s radiator is huge. In the end, the entire radiator looks very complete, and it is difficult to find traces of bonding without careful observation. These brackets are hidden behind the auxiliary fan shroud, and they are indeed relatively invisible. I’m very happy with the result, it achieves authenticity without sacrificing reliability, and apart from the two seams, everything is just the way it was.
This is what the entire system looks like after it’s installed. I believe it will also attract people who see Octavius in the future just as it once attracted Niki Lauda. I also enjoy explaining the stories to people, which is definitely the highlight of my restoration. It definitely deserves its own article. However, restoring any part on 140 is no simpler than this, always be persistent and patient.
