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Tim Hartney

142 Posts

Posted - 12/30/2005 :  17:59:56  Show Profile  Visit Tim Hartney's Homepage
Thinking about buying a 600?
Here's some advice for first timers.

Most anyone who is at this site already knows that this is an elite car so I won't add to all the superlatives you will certainly encounter while shopping for a 600. What must be kept in mind is that there are likewise superlative repair and upkeep costs with these cars. The purchase of a 600 should be undertaken with at least a bit of knowledge about what these cars are all about. A few people have purchased these cars blindly and lived to tell the tale without major mechanical or financial catastrophe. These are the EXCEPTIONS! Many people have bought 600s that, for one reason or another, were less than ideal, sometimes in the extreme! This thread is intended to give the potential 600 buyer some basic knowledge to help insure that they make an informed buying decision, hopefully with no surprises.

Having said that, I feel a few words about "cars as investments" is in order here. While is is true that 600s are quite rare and going up in value as time passes, it must be remembered that they are also cursed with four doors and (except for the landaulets) fixed roofs. Personally, I don't buy cars "as an investment". There are some people who can do this successfully, but they aren't buying 600s to accomplish any goals for a portfolio! These cars are a passion; a labor (and expense) of love. They are best enjoyed as the magnificent driving machines that they are. Any potential appreciation in these cars' value will almost certainly be more than offset by the ownership and upkeep costs. There may be an occasional exception to this, but in short, if anyone uses the sales pitch that you should buy one of these cars because of potential appreciation in value, you're dealing with someone who is nowhere near as smart as YOU now are! This doesn't mean you should walk away just yet, but be wary! Now for a bit of background on these cars.

The 600 was produced from 1963-1981, during which time a total of 2677 600s were made. US versions were discontinued after 1972 due primarily to emission and other US regulations. The cars came in three main configurations:

The basic five passenger limousine, also known as the SWB (short wheel base).
The LWB or Pullman which was a stretched version...much rarer.
The Landaulet, which was a LWB that had a convertible top for the rear occupants...EXTREMELY rare.
There was also a subtype of the Landaulet known as the Presidential Landaulet which had a longer convertible top.

Below is a list of the yearly production figures. I list them here as a way of verifying that the VIN number approximately matches the supposed year of the car. The last four digits of the VIN numbers are the exact sequential number of production. For example,100.012-12-001345, is the 1345th 600 built. I have seen ads for cars where these things were out of whack...IE a supposed 1966 model with a VIN number ending over 1000 should raise a flag right off the bat. These numbers should be considered as a guide only; the exact model year/VIN can sometimes be a bit vague as you transition from year to year. A supposed '71 model ending in 2245, for example, wouldn't cause me any real concern if all else is in order. Here are the figures:

Production 1963-1981

Year #made Last one built that year

Total 2677 units, 2190 SWBs, 423 Pullmans, 59 landaulets.

Generational differences

There are essentially two "generations" of the 600: The early versions ran through the end of the 1967 model year. The later versions began in 1968 until the end of production. The primary differences between the two versions are as follows.

Early versions:
Generally more wood. The entire instrument binnacle is wood, there is a wooden console tray between the front seats, and an additional wood piece under each door armrest.
Earlier version of air conditioning in the climate control system.
Early style wheel covers.
Hydraulic door assists.
Non-US models have a more rounded glass lens on the headlights.

Later versions:
Leather covering instead of wood on instrument binnacle and elsewhere.
An improved air conditioning system in which a tall center console compartment can be utilized as an refrigerator.
Later style wheel covers (usually).
No hydraulic door assists.
Non-US models have the flatter headlight lenses.

There is no correct answer as to which version may be the "better" of the two. The later versions definitely cool the cabin better on hot days, and there is no denying that having a fridge in the armrest is really neat. However, I just love the extra wood in the early versions...they have a more inviting look to them. On the other hand it should also be noted that the hydraulic door assists on the early cars are another gadget that can be troublesome. I wouldn't consider them a deal-breaker, but one should be aware of them and make sure they work properly.

The two styles of wheel covers actually changed over in the 1969 model year, so it would be "correct" to have early ones all the way through 1969. The wheels themselves did not change, so either type of wheel cover would fit any 600.

Below, are pics of some of these differences.

Early binnacle

Leather binnacle

Early console Pic coming soon!

Late console

Inside the fridge

Early wheel cover

Late wheel cover

Extra door catch on early lock with door assist Pics coming soon!

Now that you know some general stuff about the 600 model, here is some more detail about these beasts. Please note my "disclaimer" in the following paragraph.

I list the following areas of vehicle inspection so that the novice purchaser will hopefully be able to determine if a car warrants further consideration and the added NECESSARY expense of a thorough inspection by someone mechanically familiar with 600s. No one should buy one of these cars unless it has been inspected by a well qualified 600 technician. With this guide, you should be able to weed out cars that obviously have too many areas in need of attention. I have tried to make it as complete as possible, but to use this guide by itself, without a "real" inspection, is a risky proposition and I advise against doing so.

The Grand 600 employed what was then cutting edge technology in all aspects of its design. As a result of this, the car has features and systems that can be extremely complicated and expensive maintain or repair. Once they're properly set up and sorted out, however, they absolutely MAKE the car. Here's an overview of the main systems on these cars and some things to watch out for.


There was only one engine used, the legendary 6.3 litre V8 which was designed specifically for this car. It was available in various states of tune depending largely on where it was to be sold. The differences are most pronounced in the US market where earlier cars generally have a bit more power than later ones as compression was lowered in about late 1970.

All of these cars used a Bosch mechanical fuel injection system (MFIS) for fuel delivery. This was top shelf stuff back then, but the system can have quirks, especially when it is a few decades old. Unless the main injection pump (sitting in the "V" between the cylinder banks) has been rebuilt within the past 5-10 years, you should expect that this will be needed. One fairly reliable sign for needing such a rebuild is the presence of oil/fuel in the "V" under the pump. This may have other causes, but anticipating the worst case scenario will leave you better prepared as a buyer. There are other minor quirks with this system, but none that will likely cost as much as an injection pump rebuild.

It is very important to know the condition of the fuel system that leads TO the MFIS (injection) pump. Go to this part of the M-100 web boards for Dan Smith's excellent advice on this:

To sum up: fuel tanks, lines, filters, tank senders, etc. can all get badly fouled from corrosion ESPECIALLY in cars that have been SITTING for a long time. If the car hasn't been run for many months, it may be wise not to even start the car until the fuel system is cleaned up and won't be feeding contaminants to the injection pump. If the car has been sitting a year or more, I would absolutely not, under any circumstances attempt to start the car until this is done. You're just begging for big problems later on if you do. If the car has been started and driven fairly regularly, this shouldn't be a major concern at this point, especially if the car runs well.

Obviously, if the car runs rough at all, this needs to be looked at by someone who is qualified. Don't buy into the 'ol, "oh it just needs a tune up". That may well be all it needs but it may also be a sign of bigger problems. Most of these cars have a slightly "lumpy" idle. If the car runs strongly otherwise, it's probably not a big concern. Be sure to try both fully cold and hot starts. Tricky hot starting (after several minutes of sitting, engine off) isn't unusual on these cars, but it can usually be remedied without being extremely expensive, but do add it to "The List".

The transmissions on these cars are pretty tough, but a couple of things should be kept in mind. First, know that age all by itself can lead to the need for a rebuild, even with fairly low mileage. I know this because it happened to me, and I had no expectation of trans problems on a 70000 mile car. Also you should know that these trannys shift quite firmly. This is normal. A slushy shifting trans is a definite sign of trouble, especially under hard acceleration.


Perhaps the scariest system (in terms of costs) on the car is the "comfort hydraulic system".
This system operates a large number of accessory functions, most importantly, the windows, seat adjustments both front and rear, trunk operation, sunroof, door assists (early models only) and a number of other things. Rare is the car in which this system functions perfectly. With the car running, try operating everything in sight: all windows, front and rear seats, sunroof, heating and A/C, center vent flap and last but not least, the trunk.


The trunk on these cars must NOT be closed by hand! Open by pulling the latch, close ONLY by pushing the latch button in. Trying to close the trunk by pushing down on the lid as in a conventional car WILL damage the lid and/or hinges!

If the above procedure does not, by itself, fully open and close the trunk, than the trunk needs repair...add it to "The List"!

While checking the various functions, keep an eye open for leaks. Red fluid on the door sills is a fairly common site on these cars. Some leaks are not too pricey to fix, while others may be a nightmare. Small amounts of seepage are often not worth the expense of repair, but any leaks should be noted and, if possible, diagnosed prior to purchase. Items that function very slowly or not at all are often in need only of an adjustment. However, in extreme cases of wear, window switches in particular may require replacement and this can cost literally THOUSANDS of dollars (yes, you read that right!). Most other switches don't wear out far enough to require replacement as they generally get less use, but it is still possible. Fortunately, most of the hydraulic components can be rebuilt, but even this can by very costly. My main point that you go in to this with your eyes open. If there is any hydraulic accessory that isn't right, having this system checked by an expert prior to purchase may save you a ton of money. Make sure each of these items in noted on "The List"!


This system is operationally identical to the systems found on 109 body 300 series cars and a number of the components are actually shared with the smaller 300 models. One significant difference is that the air tank has two chambers, one of which is used for power boosting the brake system. With low pressure in the system, one will see a BRAKE warning light since that system has priority over the suspension, yet they "share" a common air source. The brake system is separated from the air suspension beyond the air tank so that a leak in the suspension won't cause loss of brake pressure.

Try to ascertain how long the car will stay up between starts. You'll be trusting the seller's answer on this, but if it's in terms of hours, obviously the system is leaking badly. If it's days, you're probably OK, but remember that these things always worsen with time, so next year you may well be down to "hours"! A decently functioning car will stay up for several days at least, ideally for weeks. If the car wasn't up when you first arrived to look at it, take note of how many minutes it takes for the light to extinguish once the engine is started. If it's much more than a few minutes, you have a pretty darned leaky system, a worn-out air compressor, or both. Another check of the condition of the compressor is to drain the tank and see how gunky the condensate is.

Look under the left front fender and you will see an oval shaped tank with two drain valves on the bottom of it. One is for the suspension system, the other for the brakes. Unless you like oily hands, wear a glove or something and push each drain valve sideways. You will probably get at least a little brownish crud out. If it is much more than a tablespoon or so, it indicates that either the tanks haven't been drained in a while OR the compressor may be getting worn (or both). After this is done, again see how long it takes to extinguish the warning light. A lot of muck and a long time to regain operating pressure definitely means it's time for a compressor. These can be rebuilt and aren't extremely costly, but...add this to "The List".

It must be remembered that air suspension systems WILL eventually become leaky, no matter how perfectly they stay up now. Here's the part that throws people: the usual culprit isn't the rubber air bags. Those can be a leak source, but far more likely is the leveling valves under the car. The reason for this is that they are always moving and the tiny synthetic seals inside these valves begin to wear and air begins to seep out. This leakage tends to worsen in colder weather; some cars stay up for weeks in the summer, but only for days in the winter. No matter what, PLAN to have to replace all three leveling valves about every 4-6 years. They are a wear-out item...it's just a fact of life.

Now for the good news: These valves are also rebuildable. A full set (rebuilt) should be in the $1500 ballpark...not all that bad as 600 parts go! Installing these is pretty straightforward, too.
Obviously, there are several other components in these systems that can be the cause of leaks. Having a look at the external condition of the bags can generally be relied on to eliminate them as possible leak sources. If they aren't all dried up and cracked or otherwise visibly damaged, they are probably OK. That leaves things like the master control valve, pressure regulator and lines. None of this stuff is cheap, but compared to the hydraulic system, these parts are not all that expensive. Labor to ferret out leaks and install components DOES add up however, so add obvious air ride problems to ...you guessed it..."The List".


While we're on the subject of suspensions, however, I must mention an area that is MANY TIMES more expensive than air ride problems: RUBBER! Perhaps the biggest marvel of engineering these cars had was their suspension. Not just the air ride part, but the total package. These cars absolutely set THE standard for many years in combining a velvet-smooth ride with extraordinarily responsive handling characteristics. The suspension components work in utter harmony to accomplish all this and a large part of this harmony comes about because of the inclusion of rubber mounts and bushings located in just the right places throughout the suspension. The problem for today's buyer of these cars is: rubber rots with age! Much of this rubber isn't visible on the 600 without major disassembly of certain suspension or driveline components. The big problem with all of this is the cost to replace all of this rubber is so far beyond what most people would find reasonable that it is rarely done, even on otherwise well kept cars.

So, how much are we talking about? I would budget about $20,000, give or take a couple to replace ALL of it. Why so much? Because it's a 600, which means each of these rubber pieces is VERY expensive (and unique to this model), and installing them involves a great deal of labor as well. In many cases, the car IS safe-to-drive with tired rubber, but it will definitely lack the sensational feel of comfort and precise handling that these cars were (and are) so noted for. Here again, the suspension must be inspected by someone who really knows 600s to verify that it is still a safe to operate and that driving it won't cause premature wear on driveline or suspension components. Many symptoms of tired rubber will show up as it would in a conventional car such as any type of clunking or looseness in the suspension. Often, a fairly loud "click" will be heard when first putting the car in reverse. The main thing you as a potential buyer must know is that suspension noises are almost never a simple or inexpensive fix. If you have a car that has recently had much of all of this work recently done, you're WAY ahead. Proper evaluation of the suspension is one of THE MOST important things to have done prior to purchasing.


Brakes are yet another system on the 600 that can run you into BIG trouble fast. First and foremost BE CERTAIN that ALL rubber brake hoses have been replaced within the last 4 or 5 years. If this cannot be verified, the best advice is NOT to drive the car. This may seem drastic, but the consequences can be disastrous. The problem is that brake hoses, especially on cars that aren't driven a lot, tend to swell-up internally while looking just fine on the outside. This swelling makes then act as one-way valves and prevents the brake(s) from releasing properly when the pedal is released. Because of the immense power of these cars, a dragging brake may well go unnoticed until it is literally RED HOT. There have been some cars that caught fire and burned up when this happened. If there is any doubt as to the integrity of the brake hoses, just don't drive the car. These parts are one of the few that are shared with other models and are actually quite inexpensive to replace.

The brakes are power boosted from compressed air, not vacuum as would be the case in a conventional car. This booster itself is much smaller than a vacuum style booster, but it is a very expensive unit to replace. The red BRAKE warning light is an indicator of low air pressure in the reservoir tank, which is used for air suspension AND brake boost. If this light is on there is a POSSIBILITY that brake pressure is low, but more likely it is the suspension side of things that is low and the brakes will be sufficiently boosted. It's not generally a good idea to drive the car in either circumstance...the light should be extinguished before driving the car.

The remainder of the brake system is not really any more prone to trouble than that of a conventional car, so simply being alert for chattering, grinding or pulling while braking will most likely be reliable indicators of potential problems here. Some light and occasional squeaking is basically normal, however. Once again, remember that this system is completely unique to the 600 and parts are VERY expensive if serious brake work is needed. Just a set of brake pads for this car is well over $1000! If calipers, master cylinder or power booster need rebuilding, plan on several thousand dollars for a complete brake job.


Next we come to the climate control system. There's not really much that can be checked adequately by the novice buyer here, other than to be able to tell if the A/C is blowing cold and the heat is blowing hot. Both of these functions are operated by the controls at the center of the dash and if the car is still being considered seriously, the system will be thoroughly examined by your 600 expert. Parts wise, the most expensive component in this system is the control unit. Usually, problems with this unit are evidenced by the system feeding the cabin with the wrong temperature air.


The central locking system is another system that works in the same way as that of of the models, but using 600 sized parts. These systems tend to lose vacuum with age and major components can be rebuilt. A general test of the system can be done by simply locking and unlocking the driver's door with the car off and observing that the door locks, trunk and gas filler door lock and unlock with the system through at least a few cycles. Often the system will lock the car, but loses vacuum after sitting for a while and won't unlock. Components that aren't locking or unlocking or a system that bleeds down too quickly indicate leaks...more items for "The List" .


The last system we'll discuss here is the electrical system and again there really isn't much to talk about. 600s are equipped with two alternators, each of which can carry the normal electrical loads of the car. If all is functioning normally, you should see two red lights on in the speedo when the key is on and engine is not running. If either or both of these remain on after starting, it indicates that that alternator is not putting out any current. Each alternator has its own accessory belt. These belts are very small and more failure prone than they should be. The left one is easy to change, the right one is a real bear as it is the innermost belt. The alternators themselves are conventional Bosch units and are inexpensive to rebuild. The rest of the electrical system is generally not prone to many problems.


So that about wraps up the things that are unique to the 600. The rest of your inspection would be the same as for any used car, so I won't be going over that here. Assuming the car has generally passed your inspection thus far, your next problem is to get a detailed inspection by a well qualified person and try to get firm answers on the items on "The List". It may take some time to arrange for this inspection and it will likely be somewhat expensive, but it will be money wisely spent as opposed to rolling the dice on the ultimate cost of correcting a defect.

A good rule of thumb on buying any M-100 powered car is to get the absolute NICEST one you can possibly afford. Attempting to buy one "as a restoration project" or assuming that a car needing a few repairs will be sufficiently less expensive to own almost never works with these cars. Even if you are extraordinarily talented mechanically and have a great facility in which to work, it is very unlikely that you will come out ahead in the end. Additionally, you'll be able to enjoy the car much sooner than if you have a long list of work that the car needs. Don't be in a rush and try out a number of cars.

Some time back, Karl Middlehauve wrote an article on 600 purchase and ownership which covers much of what I have written here. In that article he spells out what kinds of cars you will likely end up with at different price points. Here is how he lays it out.

A car that costs this much to purchase...................................needs this much work:

Less than $10,000................................................................a parts car.
$10,000-20,000................................................................... needs $20,000- 40,000.
$20,000-30,000....................................................................needs $10,000- 30,000...a fair driver.
$30,000-50,000..................................................... ..............needs $10,000- 20,000...a good driver.
$50,000-100,000 with very low miles..................may well need $ 50,000 (the high cost of non-use)
>$100,000.................................................................... mechanically and cosmetically flawless

The above figures are for SWB models. Pullmans will cost many thousands more to purchase, but repair and upkeep costs will likely be similar.

When you find one that seems right based on the information posted here and elsewhere, get it inspected. If it passes that test, you should be able to own the "ultimate motorcar".

Tim Hartney[/b]
When in doubt...GET ENOUGH!

Edited by - Tim Hartney on 12/07/2006 23:12:45

Stu Hammel

667 Posts

Posted - 12/30/2005 :  18:36:36  Show Profile
Tim's Buyer's Guide for the 600 is an excellent jumping off point for anyone seriously considering one of these magnificent cars. It is essential to try to have any 600 you are liooking at inspected by someone who knows these cars. If the car is not near a technician who is fully familiar with the 600 model, then at least try to find a club member who owns a 600 and lives close enough to give the car as complete a going over as possible. While most of us who own 600s are not expert technicians, we have been forced to learn a lot about the cars through ownership. This experience does help.

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randy crooks

42 Posts

Posted - 12/30/2005 :  22:39:07  Show Profile
Nice job,it looks like a lot of work..A couple of things that perhaps you could mention are that the front brakes have double calipers at each wheel (fore and aft).And that there were an early and late hydraulic pressure accumulator,the newer style being mounted under the front bumper (cylindrical) and the early type (sphere) located behind the kick panel.There are probably a lot of little items like these that the other guys will think of and suggest to you also.

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Tim Hartney

142 Posts

Posted - 12/31/2005 :  10:18:01  Show Profile  Visit Tim Hartney's Homepage
Thanks, Randy.

I'd forgotten about the two types of accumulators. I don't know what the cut-off date or production # was for the early type. Did it coincide with the changes in the '68 model year or did it take place at some other time?

I'll add mentioning the dual front calipers shortly.

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Ron B

11659 Posts

Posted - 12/31/2005 :  17:49:04  Show Profile  Visit Ron B's Homepage
Refering to the Acummulator,Art raised a good point with a "seller" we visited once.He had been driving his 600 for some time with out the accumulator because he couldn't afford to repair the device.( one reason the car was for sale).The priniple of an accumulator is best described in terms of a "clock spring" ,Just as a clock spring becomes energised as it is wound up ,An acummulator 'acummulates' energy as a spring or gas pressurised diaphram inside it pressed against.This maintains the pressure in a air or hydrualic system at a prescribed level to prevent fluctuations,vibrations or harsh action of components in a system.
So...if you need an accumulator or you need to get yours repaired and cannot find an engineer capable of actually doing the job,a simple remedy is available in the form of the 6.9 sphere.

Art has two joined together to make an acummulator on his 600 which does the job admirally.Unless you are going for a prize at Pebble beach ,i think this is a better idea than attempting to rebuild the accumulator which requires a Huge amount of skill,somewhere within the capabilities of an aerospace enginneering workshop and related costings.

...Can we fix it?? YES WE CAN!!!http://www.popartuk.com/g/l/lgmp0092.jpg
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1535 Posts

Posted - 12/31/2005 :  20:18:24  Show Profile  Visit cth350's Homepage
Is the cutoff for '64/'65 correct? I was under the impression that car #101 was the last for '64 and that mine (#111) was the 10th off the line in '65. It's gone to the head of the list? Interesting -CTH
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Art Love

6258 Posts

Posted - 12/31/2005 :  20:54:57  Show Profile
The figures quoted by Tim are the same as appear in James Taylor's "A collector's guide" Vol 2. I think the confusion relates to the inclusion in Tim's figures of the LWB cars. One was made in 1963 and 8 in 1964, which when added to 2 SWB in 1963 and 99 SWB in 1964 give the quoted figures. So by the end of 1964 there had been 101 SWB cars made. It is my understanding that the LWB cars were NOT given a separate sequence of chassis numbers from the SWB cars, so yours would have been the first chassis in 1965. If the LWB cars were given a separate number sequence, then your understanding would be correct.
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Art Love

6258 Posts

Posted - 12/31/2005 :  21:40:34  Show Profile
The pressure reservoir that both Randy and Ron refer to has now been made in at least 3 forms and Karl M is probably the best person to discuss this. As Randy said, the first version was spherical and, at least in my car #178 RHD, placed in the engine bay at the front on the left. I am not certain what the American term "kick panel" means unless it refers to the sheetmetal to either side of the radiator (Randy,is that where you kicked a veteran when it wouldn't start when you cranked it???) Perhaps it's a horse and buggy term.

Anyway, the bracketing was still there in #178, but by the time I got the car it had the piston type fitted under the front crossmember below the bumper. The part number for the original accumulator was 100 800 00 19 and that of the piston type that replaced it, 100 800 03 19. The change over occurred at #369 but, as was often the case, the second version was also fitted to some earlier chasses, 355, 358, 359, 361, 362 and 367. Someone has written all the modification numbers in my 600 parts manual and this was modification #19129.

When the piston reservoir on #178 started to leak, my mechanics sent it to a local hydraulics repairer who were certain they could fix it. They failed, and as a result of that, as Ron said, the hydraulic pump was subjected to constant demand and uncontrolled pressures and failed. Fortunately, I had a spare. Karl has spoken about this very important issue at one or more of the meets as has Helmut Schattenkirschner. As the price of a replacement piston reservoir was prohibitive, my mechanic, having noted the original bracketing in the engine bay, suggested we try going back to a spherical setup using 2 Bosch spheres. These spheres that 6.9 owners are familiar with, are a stock item and come in a range of sizes for different pressure ranges and applications (the 6.9 ones are toward the smaller end of the range). So the car has been running perfectly with this modification ever since.

You can imaging my surprise when, at the last Meet held at Karl's, he showed us the latest version from M-B of the accumulator which is a two sphere setup to mount on the piston reservoir bracket. The only other thing I would note is that cars with Landaulet rooves had a different pressure reservoir part number 100 800 07 19. I don't know what the difference was.
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randy crooks

42 Posts

Posted - 12/31/2005 :  23:27:42  Show Profile
You are 100% right as to the location of the sphere,just below the electric solenoid for the air horn.I don't know why I would call it the kick panel,that's the cover over the area where on a (lhd) car your left foot would rest this panel would cover the air conditioner fan on a (rhd) 6.3 ,sorry for the mistake.But your suggestion of a place to "kick" was a funny one.

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205 Posts

Posted - 01/16/2006 :  15:07:27  Show Profile  Visit Oliver's Homepage
I just talked with Helmut Schattenkirchner because the accumulator in my car is broken (only 2-3 complete window moves versus the 25-30 that it should sustain). According to him it's a must if you don't want to kill the pump. The spheres from a 6.9 are only spec'd up to 80 psi whereas the 600 pump delivers up to 200 psi! He said he would definitely not recommend going down that road. He charges about 1,100.- EUR for rebuilding the accumulator, and claims he has been rebuilding them for 18 years now and none of them has failed again... so I guess those 1,100.- EUR are well spent...
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Tim Hartney

142 Posts

Posted - 01/16/2006 :  17:39:54  Show Profile  Visit Tim Hartney's Homepage
Is yours the early or late style accumulator?
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205 Posts

Posted - 01/17/2006 :  01:33:46  Show Profile  Visit Oliver's Homepage
Tim, my car is #402, so it already has the cylindrical accumulator... HS said the early styls accumulator cannot be repaired, so the newer style one has to be retrofitted...


Edited by - Oliver on 01/17/2006 01:35:24
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65 Posts

Posted - 01/17/2006 :  05:54:35  Show Profile
Just a few comment on the subject of the piston accumulator.

I would have to agree with Helmut Sch. and his advice against installing 6.9 HPF accumulators. If cost is a concern there is the option of fitting an accumulator from the Bosch range of accumulators (contact your local Bosch Hydraulic service) .
I have some unrepaired original 600 accumulators at my saltmine because Bosch had a cheaper solution in form of the so called bladder accumulator. (part No. 0 531 012 702)
This unit looks like a bomb and fits in the original piston accumulator space. It was mounted on a custom made alum/bracket and bolted to the old steel bracket with 4 rubber mountings (air cleaner buffers)
This type of accumulator is available from Bosch Hydr. in various sizes -
it depends on the storage volume required. It is not a diaphragm type, the name bladder accum. is used because the bladder is replacable. When it is ruptured it is pulled out and simply replaced with an new one (very convenient+cheap).

Other hydraulic manufacturers have similar units - but in my case Bosch was very helpful
and another workshop here had also used the Bosch type before. Bosch also supplies
the correct clamps for some of their accumulators.

from Western Australia
Mercedes Car Clinic
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randy crooks

42 Posts

Posted - 01/17/2006 :  12:28:01  Show Profile
That's great advice for 600 owners,I had no idea that bosch sold replacements for the accumulators.They must work on the same principal as residential water storage/pressure tanks (people with well water).The water is pumped into a stretchy rubber bag inside a steel tank,as the bag is stretched from the pump pressure it is counter acted by air pressure inside the steel tank,acting as a cushion or spring.Do you know what is used for the counter pressure on the bosch units,is it still nitrogen or just air.

Thanks, Randy.

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205 Posts

Posted - 01/17/2006 :  13:34:05  Show Profile  Visit Oliver's Homepage
Walter, thanks for the insight! What's the price of such a replacement accumulator?

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Art Love

6258 Posts

Posted - 01/17/2006 :  19:04:18  Show Profile
That's just the Bosch spheres that I am talking about in my post above on Dec 31, that are working well on #178. I presumed they were a larger version of the suspension spheres in the 6.9. Sorry if I caused confusion by mentioning the 6.9, that is my ignorance. I did not intend for anyone to use 6.9 spheres. Based on the location and remaining bracketing in the engine bay of #178, the original 600 accumulator fitted to the first 350 odd 600's must have either been one of these or something very similar. Do you know?
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