First a quick history lesson on the MB hydraulic suspension.
Accumulators or Spheres as there sometimes called are the "springs" of most of the 140's rear suspension. The ride leveling system was installed on all 500's and 600's, optional on 420's and not installed in 300/320's - at least in the States. I've heard second hand that it was optional on 500's for most other markets. There are two different systems installed on these cars. The basic is a rear ride height control only and this system has no center console control switch- the system is transparent to the driver. This system has two accumulators. The other system has three accumulators and can be identified by a small switch on the enter console with a pictogram of a shock absorber. This system is called ADS or ADSII (Adaptive Damping System) depending on the model year. Basically this allows you to firm the suspension on all four corners. This system also controls the oil flow in and out of the front shock as well. This article deals with the two accumulator system because that's what I own- a 1997 S500 with ride height control. If you have ADS, the procedure is substantially the same- your just replacing three accumulators.
After about 80,000 miles the ride in these cars starts to deteriorate. Bumps that once went unnoticed now start to jar your hind teeth. When you notice that your starting to avoid manhole covers- it's time. What happens is the Nitrogen pre-charge starts to leak out. In a new accumulator, the pre-charge is set to 155bar- that's 2279psi! When the car hits a bump- hyd fluid is forced out of the shock and into the accumulator via a hydraulic line. This compresses the nitrogen gas inside the sphere- as the suspension expands on the back side of the bump the pressure inside the accumulator forces the fluid back into the shock. As the accumulator ages, the pre-charge leaks out and the void is filled with incompressible hydraulic fluid. This is where the ride stiffens up. When all the pre-charge is gone you basically have a hydraulic lock and the suspension stops working. My mechanic says he's seen cars come in where you can't compress the rear suspension even by jumping on it. It would be funny except that if you let your suspension go that far you risk damaging the hydraulic shocks- there about $870.00 a piece to replace. The accumulators are about $100.00 a piece to replace. You do the math.
In the two accumulator system, they're located approximately under the rear seat- tucked up and bolted to the underside of the floorpan. The driver's side (left-hand drive) accumulator is obscured by the exhaust system - not a problem. On cars equipped with xenon headlights, the right accumulator is blocked by the headlight level control. Simply unplug the electrical connector and remove the controller. Here's a few drawings from ALLDATADIY.com located at the bottom of the text.
On to the messy part!
Regarding the accumulators, the job is pretty easy, if not messy. Jack up the rear. If you don't have two floor jacks, try this- chalk the front tires and use the supplied tire changing jack to lift the car. Place a jack stand under the lift point (rubber doughnut) and set car on the stand. Move to the other side and repeat. Not ideal but it works. Please be careful! You might want to even "chalk" the car jack as it contacts the ground at an angle and on a slippery garage floor- well, it could slip. Bleed off as much pressure as you can using the nipple on the level control valve. I stuck some clear plastic tubing on to the nipple and cracked it open to let the hyd fluid and foam escape (brown foam means your accumulators are indeed bad). Once this is done you can remove the doughnuts or hangers that attach the exhaust system to the under side of the car. I think there were two on either side of the muffler and one just aft of the cats. I just unbolted them from the floor pan. This allows the system to hang down just enough to remove the driver's side accumulator. To remove the accumulator, simply remove the two hyd lines that attach to the accumulator and then remove the three mounting bolts. Prepare for an unholy mess at this point. Despite all my best efforts and warnings from other people I still dropped about a quart and a half of oil on the garage floor. Both sides require some finagling to get the accumulators out of their hiding spots but they will come. Some people have had trouble removing the hyd lines from the accumulators. This seems to be more of a problem for cars located in areas that use road salt. A good flare nut wrench is what is required here. This wrench looks like a standard box end except it has a small gap at the end that will allow you to slide the wrench over the hydraulic line. This wrench will help prevent damage to the soft metal nuts that hold the hydraulic lines to the accumulators. It should be noted that I was able to remove the lines with a standard wrench with no problems. Also be very careful not to cross thread the nuts onto the new accumulators. The hydraulic lines are stiff and if you don't line them up perfectly, you can cross thread the nut. This proved to be the most difficult part of the task. I had one on the right that would absolutely refuse to thread correctly. Patients, a beer, and another whack at it did the job.
Once both accumulators have been replaced I followed ALLDATADIY.com's instructions for filling and bleeding the system. Here's a reprint:
FILLING:
Pour oil into the oil reservoir
Only reuse clean oil
Set level controller lever to "Fill" position (F)
(loosen the ride height linkage- this will allow you to move the lever between FILL and EMPTY)
CAUTION
Risk of accident due to the vehicle starting off automatically when engine is running
CAUTION
Risk of injury due to bruising or burns when intervening while starting the engine or when the engine is running
Start engine, allow to run at moderate speed for approx. 60 seconds
The system bleeds itself automatically
Switch off engine
CAUTION
Ensure that there is sufficient oil in the oil reservoir
The pump must not suck in air under any circumstances
Set level controller lever (arrow) to position "Empty (L)"
After approx. 60 seconds, attach connecting rod or connecting linkage (7) to level control lever (arrows) NOTE:
Replace self-locking bolts and nuts
Place vehicle on its wheels and press down firmly several times.
The vehicle level adjusts itself
Check and correct oil level in oil reservoir
Be careful not to over fill the reservoir. I got a little too concerned about running the pump dry that I overfilled the system. Remember that when you move the lever to FILL, your filling the accumulators and raising the suspension. This will lower the reservoir. When I saw the low level ( lever still on FILL) I topped it off. Oops! When I moved the lever to EMPTY (engine off) The accumulators purged their oil and it flowed back into the reservoir. I heard this strange squirting sound. There was oil all over my garage wall. It had squirted out the overflow which thankfully had been pointing toward the front of the car and not into the engine compartment. Nothing bad happens if you overfill the reservoir- it's just messy and embarrassing.
Good luck!
Paul[img]http://[/img]
Hey guys, i just ordered my new rear hydraulic shocks for my 95 S500 from autohausaz.com, is there such a thing as a suspension filter for the hydraulic suspension oil? here is a link: https://www.autohausaz.com/search/pr...nsion%20Filter
if it's true where is this filter?
Vehicle: SEC 600 COUPE (RHD) One of the chosen few.
Location: Leicester UK
Posts: 1,358
yes thats the one in the reservoir at the font.. check my gallery for better pics.. also the third sphere on the rear, could be for the locking diff, if you have one.. a button with snowchains on a tyre will tell you you have.. otherwise the third sphere is at the front behind one of the wings i am told..
__________________
If you've GOT to have a extension,
Have a BIG one.
This article describes replacement of the alternator bearings in my 1997 S600 sedan. Keep in mind that different model years may be different. My alternator had been making quite a racket for some time. Electrically it was fine, so I figured it was just the bearings that were bad. If it was just bearings, I wasn’t inclined to pay for a completely new (or rebuilt) one. I was right. With the new bearings, the alternator runs quiet and smooth, now. This Range Rover web site covers bearing replacement in the Range Rover Bosch alternator.
I found my W140’s alternator was nearly identical with the exception of a larger front bearing.
Special tools for the job:
1. Gear/bearing puller (a generic puller is fine)
2. Impact screwdriver
3. 10 mm 1/2 in drive triple square driver (I bought a set of 4 SK brand triple square drivers.)
4. 22 mm tool to turn the pulley nut. My father-in-law had access to a welder so we made one using an old wrench and a 22 mm 1/2 in drive socket. The official Bosch alternator pulley nut tool looks like a deep well crowfoot socket, only the “crowfoot” is a complete socket going all the way around the nut. Here are the triple square bit and the pulley nut wrench that we made.
We ground down the triple square bit a little and drilled out the socket so that the bit would fit through the socket. See the part about pulley removal to see a pic. Alternatively, an air impact wrench may work to remove and install the pulley nut without messing with special tools.
Removal of the alternator is not simple. It seems nothing is in the V12’s engine compartment. You must remove the front anti-roll bar, and you must drain the coolant and then remove the lower coolant hose.
1. I put the front wheels on ramps to remove the anti-roll bar. It seemed there was a little tension on the anti-roll bar when the wheels were allowed to hang. Getting the bar off the end links (and reinstalling on the end links) was easier with the suspension compressed with the wheels on ramps. Do not work under your car without the car properly supported (lift, jack stands, or ramps)!
2. Disconnect the ground (negative) terminal on the battery. You will need your radio code to reactivate the radio, and you will have to reprogram the express function of the windows when you’re done.
3. Remove the ADS sensor attached to the right side of the bar. Of course, if you don’t have ADS, you won’t have this. Disconnect the electrical connector and remove the U-bolt and the two nuts holding the bracket to the studs. (Everything is so clean because I took these pics during reassembly.) Note the flat on the bar that locates the sensor arm.
4. Remove the 2 nuts attaching the sway bar links at the end of the bar. These are ball joints, and you will likely have to counterhold the stud with a 6 mm allen while turning the nut. I used a crowfoot on the nut and let the counterholding bar lever itself against something solid. These nuts are self-locking and should be replaced with brand new ones. They get 80 Nm of torque.
5. Remove the 4 nuts (2 on each bracket) that attach the bar to the frame, and remove the bar. These nuts are also self-locking and should be replaced with new ones. These nuts get 20 Nm.
6. Disconnect the 2 wires on the backside of the alternator. You have to crawl all the way underneath and look toward the front of the car above the cross member to see the back of the alternator. I used a long extension to reach forward to the alternator.
7. Remove the lower coolant hose. Here’s why you need to remove it. It blocks removal of the bolts. In fact, there is a nub molded into the hose to keep the alternator mounting bolt from rubbing through the hose.
You can simply separate the hose from the radiator and let it drain, or you can drain from the radiator stopcock on the left side of the radiator and then remove the hose. About 2.5 gallons will drain out. Have a big enough container and make sure it is clean if you will reuse the coolant.. To drain from the stopcock, pop out the panel on the left side of the bumper (where the outside temperature probe is mounted). You will find the stopcock right behind the panel. Put a clean hose on the nipple, and open the stopcock with a screwdriver.
Drain completely, and then remove the hose clamps on the hose and remove the hose from the radiator and the water pump.
8. Slacken the belt and remove it from the alternator pulley. No picture here since I really couldn’t get a good one. It’s a tight squeeze. Working from underneath on the left side of the engine, put a 15 mm socket with a breaker bar on the nut in the middle of the tensioner pulley, which is just to the left side of the crankshaft pulley. I had to push the fan shroud around a bit to work the socket onto the bolt. Rotate the tensioner to release tension, and remove the belt from one of the pulleys. Then work the belt off the alternator.
9. Remove the 2 alternator mounting bolts and remove the alternator. The bolts are 15 mm.
10. Remove the 22 mm pulley nut. With the alternator out of the car, try your impact wrench on the pulley nut. If you don’t have one, get your special tools out. You may need to get creative with bracing one wrench and turning the other. The nut is spun on there pretty tight. I don’t know what the recommended torque is.
11. Remove the plastic backing. Remove three small screws and one large screw. Then release three clips around the perimeter, and simply pry the cover off.
12. Remove the voltage regulator. Here are the numbers on my alternator’s regulator.
The regulator is held in by 2 phillips screws. Remove them and remove the regulator. The brushes are spring loaded. Note how much length is left. If they are almost worn completely down, you should try to replace the regulator. I’m not sure if you can buy these regulators easily. You may have to see if a rebuilding shop will sell you just the regulator.
13. Split the case. Mark the case halves so that you can put it back together correctly. Remove the 4 bolts around the perimeter, and pry the case halves apart. The front half will come out with the rotor attached.
14. Recover the rear bearing cup. The rear bearing has a plastic cup on it. It may have stuck in the rear case half. Find it, clean it, and don’t lose it.
15. Pull the rear bearing off the shaft. Do not use pressing force on the plastic end of the shaft. What looks like the end of the shaft is actually a plastic sleeve formed over the shaft, that holds the electric contacts (the copper slip rings) for the voltage regulator brushes. Guide the tip of the puller into the center of the hole so that it contacts the metal shaft directly.
Note the bearing markings. The rear bearing is a standard size 6203 bearing (40 mm outer diameter x 17 mm inner diameter x 12 mm width). You can find this bearing online at many bearing sellers. Make sure to buy the 6203 2RS (2 rubber seal) bearing. You can go with the inexpensive Chinese or Japanese import bearing, which costs about $6, or you can go with a name brand one for 7-8 times more (SKF or FAG). I decided to try the cheap Chinese made bearing. If the bearing goes bad in short order, I will consider getting the more expensive bearing next time.
16. Remove the rotor from the front housing. First remove the 4 screws in the face of the alternator. These can be corroded and stuck pretty good. I used a hand impact screwdriver to remove my screws. I replaced them with new stainless steel screws and used a little anti-seize paste when reassembling. I then used a hammer to drive the rotor with the front bearing attached out of the housing.
17. Pull the front bearing and thrust washer off the shaft. Note the orientation of the thrust washer. It has a shoulder on the side that faces the bearing. The front bearing is a big bearing that is apparently an oddball size (52 mm outer diameter x 17 mm inner diameter x 17 mm width). I looked and looked and could not find this bearing from any online bearing sellers. I called Nachi, the maker of the bearing that came out of the alternator, and the response was that was not a bearing that they import to the US. I then called a local alternator rebuilder who said he had the proper size bearing and would sell me one for $45. Here’s the bearing:
It has almost no markings on it, so I can’t give any advice on where the average joe can find one. It’s probably a cheap import that cost him about $10, if that much, but I didn’t mind paying the mark up given the trouble I had trying to find one. I was so excited to get it, I didn’t even think to ask his source. (note: I have since located this bearing online. If you google "alternator bearing" you will find sellers of this bearing. Apparently, it is a bearing specific to automotive alternator applications. I have seen the bearing listed under these part numbers: B17-99 (the number on the bearing in the pic above) and also B3043-2RDA. I bought one from this site, http://bearingsdirect.com/products/i...category&id=56 .)
18. Reassemble the alternator. Putting it back together is straightforward. Install the rear bearing on the shaft. I used a deep well socket as a drift and drove it on lightly with a hammer. Press the new front bearing into the front case. I used a block of wood and a hammer with a squirt of WD-40 for lubrication to seat the bearing. With a little more WD-40 on the shaft, the shaft slid right onto the front bearing. Don’t forget the bearing retainer plate, which has to go on the shaft before the front bearing. Install the 4 bearing retainer screws in the front of the case. Replace the plastic rear bearing cup in the rear case, and mate the case halves with the 4 bolts. Reinstall the voltage regulator, and replace the rear plastic cover. Finally, slip the thrust washer back on the front of the shaft (shoulder toward the bearing), and reinstall the pulley using the tools.
19. Reinstall the alternator in reverse order. Replace the coolant hose and anti-roll bar. Reconnect your battery. Refill your coolant reservoir. Start it up, and top off the coolant as necessary with 1:1 distilled water to MB coolant.
My total cost was around $70 (bearings + new screws and nuts). If that front bearing were readily available, it would have been much cheaper.
Brett
Last edited by Brett San Diego : 02-21-2007 at 07:42 AM.
Let me know if I can be of assist? Nails and everything else is Caked w/ dat Hydrocarbon stuff..... keyboard is full of oil grime too....I here for yall, just ask! Gunner "Semper Fi"
a very helpful thread! I'm going to change my Mercedes ignition coil next week. I'm planning to do it myself. Hoping to do it right and there would be no problem.
I have a tip for those that have to replace the accumulators on the coupes. Use an 11mm crows foot flare nut wrench to loosen and tighten the nut. I had std. flare wrench and could not get the nut tight. The base hobby shop had a complete set of these jewels. I changed both cells and the leveling valve in 3.5 hours.
Cheers,
Steve
__________________
1992 300CE 150,000
1997 S500 Coupe 47,000
**********Changing the w140 ticking time bomb! (part # 1408301696 )***********
This applies to all 6, 8 and 12 cyl engines
Change this every 100k miles .. it will break without any warning
the part is approx $50 @ the dealership (give or take $10~$15), and quite simple to change on 6 & 8 cyl engines (under 20 min), and more difficult on v12s
Here I am standing in front of the car, and pointing to the part. To the right of my hand, you will see the left spark plug cover (this is on the V8 engine with the air cleaner removed). You will see the firewall right behind the part in question
This is a pic of the old part while on the car - it's dusty so it looks greyish/whitish
I am just holding the new part (the way it would go on) to show you the orientation of the part, so you can visually get an understanding of how it fits. The plastic pipe is horizontal, the fatter pipe points to the driver's side (on LHD cars) and smaller pipe points to the passenger side.
old broken part and the new one (can you spot the old part ) .. Also, ignore the part # that you see in the pic. The part # you need to ask for at the dealership is "1408301696" which refers to the 3 parts combined. The part # you see on the plastic pipe refers only to the plastic pipe which the dealer does not see seperately and they wont list it in their computer d/b.
The little piece came off as soon as I loosened the clamp and pulled on the rubber line just a tiny bit
I have to emphasize.. while this was on the car, it did not leak, and you could not tell that it was broken but it was. When I gave it a gentle pull it came off... it wasnt because I was rough or anything.. I gave it a very gentle pull... it was already broken inside, waiting to pop
go and get this done now... and do it every couple of yrs
part # is 1408301696 .. seriously don't put this off.. I don't want any of you to lose your precious 140's over a small plastic part!
__________________
96 S500 Coupe. Black on black, 18" AMGs
**********converting self levelling (SLS) rear shocks to regular shocks.*******
You can do this using MB parts from the dealer. For the price of 1 hydraulic shock, you can get 2 new rear shocks, 2 new rear springs, 2 shims/pads and labour!
The SLS springs look identical to non SLS springs but you cannot use SLS springs with regular shocks. The rear of your car will hit the floor as SLS springs are too weak to support the weight of the car. You will need non SLS springs + shims in addition to regular non SLS Bilstein shocks. You can get all these parts from your local MB dealer, and part #'s that worked for me are listed below. The car's ride height is correct after the conversion (pic attached below) and rides very well. Afterall, I did use OEM MB parts.
*Pads/shims*
The pads/shims come in 4 sizes:
1403250184 - 8 mm
1403250284 - 13 mm
1403250384 - 18 mm
1403250484 - 23 mm
I had the 13 mm shims on my car with the SLS setup. To get the correct ride height after the conversion, the 23mm shim worked well for me.
*Rear shocks*
Bilstein rear shock part # is F4-B46-1707-H0 and retails for $125 cdn / each
*Rear springs*
Here are the W140 spring choices:
(look wise, SLS vs non SLS springs look absolutely identical in shape, size, & appearance)
My SLS car had 1804 springs. I assumed the logical corresponding non SLS would be 1704 since load rating for both is the same, but in reality, I end up with a low rider. The correct non SLS spring is 2104 along with a pair of 23mm shims
Just a FYI: The springs by themselves MUST be able to support the weight of the car without any assistance from the shocks, and produce the correct ride height and have the car"sit" correctly. The shocks do not contribute to the ride height/stance in any way
The swap of shocks and springs is a not tricky.. any indi shop can do it. If you do it yourself, be very careful as the springs pack a LOT of tension and can seriously injure/kill you if you do not properly relieve the tension
now the oil lines:
remove the accumulators and suspension valve... you will see a feed line and a return line going to the suspension valve. If you follow these lines, they run under the car along with brake and fuel lines all the way to the front. In my car, the suspension lines were the 2 outer lines, but my recommendation is for you to locate your suspension valve and simply trace the lines to be sure.
Be sure to loop the feed/return line before the suspension valve as the susp. valve produces the high pressures that go to the accumulators.
all you do is have an indi shop cut the feed line and return line closer to the front of the car (for a cleaner look) and make flair fittings (similar to brake lines) to route the feed line back to return line. This will take 30 min.
alternatively, you can get a non SLS p/s pump, and replace the pump and remove the SLS haydraulic reservoir and all the associated SLS crap!
anyway.. the total cost was $1000 for 2 new Bilstein shocks, 2 new MB springs, 2 shims and all associated labour!
Ifyou are in Toronto, contact me and I will set you up with the indi shop that did my car .. I am very happy with his workmanship and prices
here is the car's stance and ride height. There is a bit of a shadow on the rear tire making it look like it's tucked in. It is not! There is a very small wheel gap and the ride height/stance is indeed correct
Just removed my side panels ,to glue the leather ,it wasn't hard but ,maybe some one will need it in the future.
1st picture is the reason why i decided to remove panels. 1.jpg
here are the steps:
1st : remove one of the seat belt so you can take the panel off. phpCaYhy9PM.jpg
2nd :remove door seals front and rear doors,loosen two screws on the bottom plastic part don't take it off its unnecessary phpHNp0OWPM.jpg
3rd: unscrew the hanger off the panel phpvFOGGwPM.jpg
4th: after you will take door seal you'll see two metal clips on both sides driver and passenger side , take them off. phpeiApz8PM.jpg
5th:All clips are off,now pull the top of the panel ,theres a metal clip inside ,use the long screwdriver to pry it out -both sides phpxsNumjPM(2).jpg
thats it ,when you ready to reinstall it make sure that the ball
goes in the hole phpDLBjHiPM.jpg
thats it hope it helps.
) .. Also, ignore the part # that you see in the pic. The part # you need to ask for at the dealership is "1408301696" which refers to the 3 parts combined. The part # you see on the plastic pipe refers only to the plastic pipe which the dealer does not see seperately and they wont list it in their computer d/b.
Seat belt trim removal 
Linear Mode
