This information kindly is provided by Chris is posted for the benefit of owners of 'A' Class cars fitted with Automatic transmissions, it will give you some idea of what is involved in changing the transmission fluid when undertaken at your request by a garage along with the parts you should expect to see on the invoice.


If you have been considering doing this job yourself then it is recommended that only experienced DIY enthusiasts tackle this procedure. I received this e-mail from Paul which is what prompted me to ask Chris for the information.
Quote
When Mercedes did this for me three years ago, it was 320€ and as far as I could tell, the mechanic spent most of his time chatting to his buddy while the transmission warmed up...
I was GOB smacked when I got the bill - I thought I was going to be there for an hour at the most... three hours later I was finally back in the car!!!
I should have asked for an estimate first.
Anyway, the gearbox has been 100% reliable and I've just gone past 150000km so I guess peace of mind comes with a price tag.
I'll give the procedure a go this weekend.
Thanks again
Paul Unquote


So you can instantly see that getting Mercedes-Benz workshops to do this job is costly, I suspect mainly because of the time it takes, it would be asking too much for the mechanic to be getting on with other tasks while the gear box warmed/heated up the fluid for instance 3 x hours in the UK is going to cost at in the region of £240 and that's the minimum cost, remember that's before the appointed mechanic has even raised the bonnet!
Plus of course the dreaded VAT.
So if you were considering getting any work done on your car, always get a quote first and if you haven't used the garage before ask them to just jot that down for you and keep it handy.
And please bear in mind I have not undertaken this task as my car has a manual gearbox so I cannot add anything to what Chris has said, however he has agreed to try and answer any questions you may have. BUT please read all of the material that he has provided through at least twice before contacting him as the answer to your question may be contained in the procedure he has provided and I'm personally aware how many times this question has come up since I have had an 'A' Class.

Please always remember not matter what the task it could be more costly than taking your car to the garage if you are not competent to undertake any procedure/repair, so always consider the situation before commencing any work on your car.
thank you lofty

I'll now hand over to Chris.

Procedure

Automatic transmission fluid/fluid change.

***Message from one of my readers 'BIG JOHN', re the dip stick mentioned in this procedure which is not installed/fitted on the automatic gearbox as standard, unless fitted by the previous owner)
Over the years posts on the forum have suggested that the automatic transmission dip stick is not available or that MB would not supply it.
Several years ago I bought one from a MB parts department without any problem it just had to be ordered from Milton Keynes for next day delivery.
The details are:- DIPSTICK for measuring automatic gearbox fluid level. Part Number: W168 589 012 100 the current cost including VAT is £17.70 12.08.09
(The part number is correct as W168xx and not the normal A168xx)

The oil filler/dipstick pipe has a plastic sealing cover retained by plastic "tamper" pin which has to be broken to remove the cap the original pin is black (as is the cover) the replacement pin is red.
The details are:- PIN Part Number: A1409910055 the current cost including VAT is £1.20
What john has said is still true today, only in the last two weeks i have had one owner tell me that MB parts would not sell him the stick saying it was for Garage use only, if this happens to you simply shop elsewhere, I contacted my branch and they agreed to sell him one, although they did ask for the part number!

So the dipstick for checking transmission fluid level is available from Mercedes parts and my branch of MB Parts at Bognor Road, Chichester, in West Sussex Tel 01243. 776111 is prepared to supply it .

. Other parts also needed are:-
1. Transmission fluid (See link below.)
2. Filter
3..Sump gasket
4. Sump plug
5.Copper washer
6. Tamperproof plug

7.Pan magnet
8.transmission fluid
I would suggest the use of genuine Mercedes fluids, bearing in mind the cost of a replacement gearbox!
I would suggest getting the transmission fully hot and checking the fluid level before starting work. If you then drain the fluid into a marked container you will know how much fluid to use on initial refill of transmission.
Removal of the sump pan to change the transmission filter and install a pan magnet [magnets were not fitted to earlier cars] is also a good thing to do.


Note:- Both the drain plug and sump pan bolts can be quite tight so proceed with care, ensuring that Torx bits are fully located in the head of the bolt.


With reference to above:










1. Drain fluid/fluid from transmission







2. Remove sump pan [note that there will still be a quantity of fluid within the sump pan which is best not relocated down your sleeve] 3. Change transmission filter

A [this simply pulls out of the transmission case]






4. Clean out sump pan using a lint free cloth
5. Install pan magnet
6. Refit sump pan using new gasket
7. Refit drain plug with new copper washer

















8. Refill with the required amount of fluid before starting the engine
9. Start engine and allow to idle in P. checking/correcting fluid level if necessary
10. Warm up transmission and shift through all gears [with vehicle stationary] while warming up.
After warming up transmission, wait at least 2 minutes and check fluid level with engine running in P or N
11. Check transmission fluid temperature
When transmission is cold, level must be between marks 2 and 4. The exact fluid level must be between 8 and 12 at 70-80 degrees c [transmission fluid temperature] If you want to get an accurate reading you will need an infra red temperature gun or similar device Temperature gun next day delivery tel 07864991164 [as mentioned previously I would suggest aiming to get the fluid level exactly on the 12 mark] Model 168, use HHT to call up current transmission fluid temperature in one of the selector positions P R N or D [this is where I used a hand held infra-red thermometer pointed directly at the sump pan to determine fluid temperature, I would also suggest checking the temperature only in P or N as checking it in D or R could prove to be dangerous]
12.(*** see information above) Insert dipstick as far as the stop, pull out, read off level. Insufficient/excessive fluid quantity causes malfunctions and transmission damage.
13. Check fluid level again. Correct if necessary.
14. Refit tamperproof cap
15. Check for leaks

Torque settings;
Drain plug 22NM
fluid pan to transmission 8NM


Note to ensure that the required temperatures I purchased an infrared temperature sensor /gun from Maplin's although this cost just on £30.00 it was well worth while and assisted me greatly in doing the job well.


Special tools for working on various Mercedes-Benz Vehicles, as well as suppliers of automatic transmission fluid level dip sticks

Sorry if this seems rather lengthy but this job is possible if you know your way round you car and are mechanically minded and it's worth taking your time remember you are saving yourself £500 at my local Mercedes dealership prices but the job must be done well & right or you will face extra costs!!
If I can be of further help please do not hesitate to e-mail me.
Regards, Chris.



Other helpful information, links and Photos kindly received from Oliver :-
For " Changing full Automatic Transmission Fluid " you can find: For WDB168 A140 year 2003 with gearbox 722700 00 246734
for the ATF : I use Fuchs Titan ATF 4000 automatic transmission Fluid
(Good price at www.opieoils.co.uk =25 £ for 5 litres For 168.589.012.100 gauge = 13 € without taxes and transport( www.mannes.fr 168.377.03.95 filter = 8€ 140.991.00.55 goupille =0,57€


Fully Automatic transmission information
I've got a 1999 full auto A160, tonight on the dash as I was driving home an F appeared. Luckily I was just arriving home, as the car didn't have any guts to get up a slight incline......OK I have an existing problem with the alternator,,,,the alternator belt tensioner is knackered however still ticking along, I'm waiting for the part to arrive so the car can be repaired on Friday....do you think if the tensioner has completely given up this could be part of the F problem?
In my view the only way there could have been a connection between these two faults was if the battery power was low caused by the belt no rotating the alternation as should be the case. Battery power is important with the automatic gearbox as it is powered by electrical circuits.
Although I have heard of this display many many times with the car going into get you mode I'm not aware of what causes it and have never seen the reason printed. I communicated this to the owner in question.
He has kindly come back with further information that may help other owners

I took the car into MB for a diagnostic check....mainly due to reading through forums and feeling nervous the car would be heading to the scrappies.
Fault stored was P1872 - Gear selector module......."fault is only stored at present and code was able to be erased, if fault reoccurs then new module is required"
They told me that the fault may or may not happen again, however had the fault been "recurring" as opposed to "stored" then a repair would be needed asap.

£73.40 including VAT for diagnostic.
Module A1683701309/7088 £274.00
Thank you Paul for the information dated 20/11/08



So in the case of the fully automatic transmission if your selector display shows 'F' there is every chance that it is the 'Gear selector module' This is the generally called the gear lever on Manual boxes and selector on automatics. This selector module does include electronic equipment and it appears it's this that causes the problem.

(Please ensure you read the correspondence towards the bottom of this page before taking any action it could save you a small fortune)

The trouble code on the Diagnostics will be P1872 and the component costs £274.00 part number A168 370 1309/7088 If this item is required on your car always use your vehicles Vin number to ensure the correct part is obtained/ordered.
Also if you have a diagnostics tool see page 69 It is worth deleting the trouble code to see if it re-appears before spending out on spares.
If you car is pre 2001 you would need to get this carried out by a garage using 'Star' diagnostics , post 2001 you can delete the code using your own diagnostics tool and it is cheaper to buy one rather than go to Mercedes-Benz for the deletion of this code.



The owner with the 'F' Problem on his car has now had the car sorted, however he is of the opinion that garages with Start diagnostics have to fit it as the module requires synchronising with the car ,

What this involves I really do not know however he does say that the whole repair only takes about an hour , see mail
Quote:-
MB "assured" me the fault was within the selector module, just under the gear stick....so although the cable harness comes with the selector unit this was not fitted as the old one was deemed OK......so I hope, as wherever the cable harness terminates...I presume the gearbox, this apparently requires the engine to be dropped to gain access. So far the "F" has not come back, although sometimes the gear change in drive can be unpredictable, for instance I can put the accelerator down but it takes more than a moment to do anything....not handy when pulling out of a junction at rush hour. The MB parts guy did say my faulty gear selector had been superseded twice so the part number of the new unit was slightly different.(will send part# later). Replacing the unit is straight forward as once the covers are removed its just 3 setscrews that hold it in position however the unit has to be configured to the car so unfortunately a definite MB job, no more than 1 hour.








Honestly the car is coming up for 10 years with 54k on the clock....if I can get another unblemished 25k-30k out of it I'll be happy.
Cheers Paul

To fit the unit complete as sold with the Bowden cable assembly, according to Mercedes, the engine has to be lowered, obviously another good design feature to ensure mercedes Workshops don't run out of business!!

It could be of course, that the fault lies in the selector Module/mechanism alone, so you may get away with fitting just that part of your purchase.
if contracting Mercedes to do this job for you, make sure you know what they are contracting to fit, in respect this complete unit, to lower the engine and replace the linkage/cables which could be perfectly sound will cost you about 6 hours in labour.





In Paul's case, Mercedes did the job free of charge, because they had botched a previous job, they therefore contacted him and explained that changing just the selector module ( Gear selector) should be sufficient to clear the defect, which is all they did, so don't get conned by being told it's a 6 hour job when all they intend doing is change the selector module, the safest way to conform the complete job has been done, if they insist is to ask for all defective parts removed on completion, remember these are your property and you have every right to ask for them, don't be put off.



It may also be the case that the module is repairable, I understand that there are a number of soldered joints that breakdown as they get older. Re soldering these joints (work carried out by an auto technician )and you may well find it cures the fault, If you are able to locate the fault then in this instance because you are simply replacing the existing repaired unit, re-programming should not be necessary. Speak to you garage in respect of this matter.



































I would like to thank Paul for the information and photographs he has provided, these will without doubt help other owners of cars with automatic transmissions to understand their car better, and perhaps have some idea what is causing the dreaded 'F' To display on the gearbox display.
Do remember when they 'F' displays on your display the your car will automatically go into the 'get you home mode' when this happens normal driving and speeds will not be possible

If you have to resort to MB workshops sorting out your problem make sure you get a written quote and also make the point that you want all bits removed available to view when picking up your car. That way you will know what's been fitted and will be able to ensure that all the new components supplied were fitted and not bypassed because the engine has to be lowered to undertake certain tasks. Few of us mind paying where a good job is done ,non of us like being conned, if an item supplied as part of a kit is purchased and then not used it is your property if you have paid for the complete kit . An example of this is the selector module that comes complete with the Bowden cable, it may not be necessary to replace this component and to do so requires the engine to be lowered increasing the cost of repairs.

So watch points . If the garage do not fit this cable and it may well not be necessary, you need to be able to pick it up with the car, the alternative is they have fitted the new cable for which you have paid and you can now view the old unit when collecting your car. Sad but we just cannot trust garages to do what they say they have or should have done, and I'm afraid history has shown that MB are no acceptation to that comment.







This photo shows the automatic gearbox /transmission removed from the car, in this instance we can see where the sector module Bowden cable connects however I'm non the wiser as to what connects onto the multi pin socket at the rear of the gearbox.
Having said that the engine needs to be at least lowered to replace the Bowden cable the reason becomes obvious as once again and like so many other things the cable is located between the under floor and upper side of the engine.





















There is little doubt that the automatic transmission is a very complex piece of machinery, these are photographs of just part of the automatic box known as the valve chest the 4 coppers brass caps housing a filter.

If you look at the automatic gearbox valve chest, right hand photo, you will see a five pin connector, at present I'm unable at present to find out what it attaches to, in fact the whole system is a mystery something I'd prefer not have on my car, at least with the manual I know how it works

There were two valve chests on E-bay this week,24.11.08 but again take care as I understand these units like the ECU are coded to the car, so if buying from any source seek an assurance in writing that it will work with your car or you could be lumbered with an expensive lump of aluminium.









So can the problem you are experiencing with your Auto transmission be attributed to your battery?
This information was posted on another forum and I feel sure that a number of Automatic transmission owners could find the information useful.

The owners had a A190 fully auto W Reg that often jumped out of gear and displayed 'F' which he found he could over come by switching off the engine for two minutes and then re-starting. All would then be well until until the next time, however his problems were worsened by the fact that when we got a cold spell the car would not start first time, as a result replaced his battery, which has also cured to date at least, the 'F problem.
OK so the battery cost him £100, but my goodness its cheaper than taking the car to Mercedes where the diagnostics test alone will cost you £50 min and the repairs, well the sky appears to be the limit with MB on this repair/problem.
The owner in question also highlighted a very good point, it's usual for original batteries to last longer than replacements, and its also the case that auto boxes appear to start their antics 'F' etc at between 50-70000, the car driven 12 to 140000 miles a year will give you almost to the day the life of the battery 4-5 years max, so if your car is displaying these problems fully charge the battery or at least get it tested it may be the cause of your problems and all though the battery will cost, it will not cost you what MB will charge you to examine your car and come up with the list of possible faults, the vast number of which could be down to the state of the battery.

ALSO I received this mail from Darren which may help other owners with problems

Lofty A little extra information for you on the W168 A170 Full Automatic The 'F' issue affected us every 2 to 3 thousand miles, however lately its done it as frequently as every 10 miles - I checked the fault codes and found gear selector module to be listed. I note that on your page http://www.aclassinfo.co.uk/mypage.59a.htm the 5th image has an arrow pointing to what's referred to as a selector lever, this is incorrect, its simply an interlock solenoid that stops you from moving the gear lever at certain times.

















I have attached pictures of the circuit board, this and the interlock are the only electronic components in the lever. It should be noted that the selector position is detected by infrared break beam sensors, not any type of copper slip connections, which means the usual culprit of dirty copper tracks or cracks is ruled out.

The circuit board looks fine, no broken tracks or dry joints, so I can only presume that if it is indeed the selector module that's at fault(sometimes the fault code could be erroneous) then its possibly a design flaw or perhaps a software fault or perhaps weakening sensor LED's.

















I have cleaned up the infra red sensors and put it all back together and so far its been fine, but its too early to call it, I will update you in a few months to let you know if cleaning helped.
Thank you Darren every little helps.
Regards Update on darrens car, it ran well for approx 4 months , the fault then reoccured and the car is at present undrivable. I will update you further informmation when I hear the outcome.









It is all worth readers John's mail who backs up what Darren has said about the infra-red sensors

Quote
Hello Lofty,
Here is some information I think your readers might like. My background is building very high performance racing engines and the cars that go with them, and I am the type of person who does not like things that do not work the way they should. I have owned many Mercedes cars because they are very well built and the brand has a good reputation. I am aware over the past few years that Mercedes has lost out in the reliability area on some of its cars. Which brings me onto the A class (W168) and the number of reports I have read about the “F” problem with the full auto box.
This is how the story goes;
I have all ways liked the A Class (Baby Benz) and it just so happened that my mother needed a small car, and I wanted a reason to find out why so many A Class owners had problems with Mass Air Flow Sensors and the F problem.

I decided to buy a used A 160 (99 model with 60K) off a well know auction site, because of the problems with the car I got a very good deal [I paid a 1/3 of the true value].
The first thing I did was send the MAS of for repair (it had a broken reed) to ECU testing, the service from this company is better than 1st class. I had the unit back 48 hours after I shipped it out, plus I got the discount [thanks Lofty].

With the MAS refitted the cars engine ran very well, but the auto box had the F problem. Now this is the bit of the jigsaw that had the most frustration in the repair. The first thing I had to do was get a trans oil dipstick from MB, it took me a long time to find a dealer that would order one for me, but in the end I got one from the dealer near Brook lands race track. This dealer is first class and the spares department people are only to happy to help.
The thing they do not tell you is how to use the dipstick; now this may sound odd, but at first I thought I had got the wrong dipstick because it was way too long for the dip stick tube, but it turns out this dipstick is used on many MB cars and it is only the end bit that counts, i.e. the stick bottoms out in the box.
When you have ALL the information it is quite simple, I was just looking at the problem to hard because of my background in motor racing.

The key to checking the oil level in this box is this; Get the gearbox up to 78C, [Do Not Guess, drop a temp probe down the dipstick or get a infrared temp gun] [after a long run the gearbox will be over 80C} go thru the gears, then put the lever into N or P with the engine running and make sure you are at 11.5 on the dipstick. If you are going to do an oil change, get the level correct with the old fluid first. Measure the amount of oil you get out of the box when you drain it (because you never get all the old oil out) and replace with the same amount of new ATF. THE OIL SHOULD/MUST BE “MOBIL ATF320”.
Just changing the oil will not on its own fix the F problem, but it is good practice to know what you are starting with, after all new oil in the box is always good.
The thing about the F problem that did not make sense to me was the fact that you could turn off the engine and the problem would go away for a bit before returning. If it was a major problem it would come back at once. The next thing I had read about the problem was from people who had replaced the car battery, and the problem was not as bad. This got me thinking, why did this made a difference.
The answer is quit simple and proves where the problem lies! And also points to the fix.
When you restart the car you put the ‘Gear selector module’ back into N, and with this the F goes away, i.e. you have cleared the problem for a short while, and if you have a new battery the problem goes away for a longer time, all this point to the infrared sensors in the ‘Gear Selector Module’ being dirty!! And why a new battery helps.

I can not take all the credit for this because half way through my repair I looked at what ‘Darren Smith’ had done, and he is 100% correct. You do not need to take the unit all the way apart, and in fact you do not need to take the unit of the car to repair, but it does not take very long to remove. All you need to do is take the gear knob off, [half twist the bottom part of the knob and then pull up, do not punch your self in the face!]
Remove all the plastic from around the selector, unclip the part of the selector that holds the circuit board, (easy job if you have the unit on the bench) make sure you do not drop the small spring or small white part that is under the S & W switch. You do not need to remove the circuit board from its plastic housing; all you need to do to fix the unit is spray it with Electrical Contact Cleaner!
I would love to know how many new ‘Gear selector modules’ have been sold because of a small amount of dirt!!

So to end my story, my mother now has a Mercedes A160 that runs like new and cost very little to repair because of your web site, a big thank from us all!! Best Regards
John Hurley.


Unquote

To try and clarify things even further I have asked john if he will explain where and how this PCB complete with infra red detectors is located and accessed he has responded with this further help document:-
Hello Lofty,
The PCB is just under the gear lever indicator panel; i.e. the bit that has P/R/N/D on it. I have attached the photos. The PCB is the gear selector module. The part on the side lower down is just a lock out pin driven by a solenoid, this is to stop you from changing gear at speed (from D to R). The procedure to remove the PCB is;
1. Remove gear knob. [twist the bottom plastic ring {on the gear knob}, then pull up on gear knob]
2. Remove the plastic cover which is attached to the centre console (by the bottom of the gear lever). {you do this by pulling up on the cover}.
3. Remove the switch panel from the centre console (windows switch etc)
4. Remove centre console. (on my model it is 3 screws, one in the cup holder, 1 each side of the gear indicator. Also I removed the hand brake lever complete; 2 bolts only). {I removed the hand brake lever this way for two reasons, 1. so I could remove the centre console, 2 I did not want to remove the hand grip off the lever}
5. Remove the plastic trim from under the radio console, the bit between the carpet and the radio console. (1 screw each side of the gear lever housing, then pull back on the trim.)
6. With the lever in 'N' unbolt the 3 bolts that hold the unit to the floor, remove the electric connectors, turn the unit on its side and push out the pin that holds the Bowden cable to the unit.
7. Remove the Bowden cable and place the unit on the bench.

To get to the PCB all you have to do now is take the unit apart by pushing down on the plastic clips on the side of the unit. {When you see the unit out of the housing it is very self explanatory)
To 'FIX' I sprayed mine with "Electrical Contact Cleaner" you can buy this at Halfords. {I sprayed mine 3 times and blow dry each time} you can spray the whole board.

Thank you John for your contributions I'm confident they will help other owners overcome what is to many an most annoying and expensive defect.
Having located the board you will be able to see the infra-red sensors which are ringed in Darren's photos above, Marked Photo1 & 2

There is little doubt that with Both darkens and John help we are a little closer to solving the problem of the 'F' Display which appears on the Auto 'A' Class World wide with no forums coming up with the answers,
If you undertake this cleaning process and it cures you 'F' problem please mail lofty so that we can see just how successful this procedure is.
John has now provided his e-mail address so if your re3ally stuck and need advise he may be able to advise you but please do not abuse his kind offer. John Hurley



Don't confuse ACS with fully automatic transmissions both are fitted to the 'A' Class .
It can be see in this photo kindly sent by an owner to try and describe the transmission on her car. Note that there is no clutch pedal and that the gear lever as appears in the model fitted with a clutch. this car is an A160 1999 model
Another owner posted that when came across the post below he thought he had found the answer to his problems unfortunately, the car in question was an Auto clutch system (ACS ) box and not fully automatic. So what he had read didn't apply to his car lets hope the info is still useful in some what way.

Chris has pointed out that the ACS transmission is fitted with the same vulnerable link as the manual transmission if you loose 4th 5th and Reverse gears on your ACS transmission check the link is in situ before doing anything else see for details

I had a 160 ACS that the pump failed on. The symptoms started with the car suddenly reporting an error on the dash and the car refusing to go into gear. At first if I switched the car off for five mins and on again it usually fixed itself. However the fault quickly got worse to the point it wasn't driveable.
I found that a sharp bang to the passenger side wing got the car going again for a short period and when I discovered this was where the ACS pump was I decided to investigate. I would recommend having a go at this yourself if you're handy with the spanners as it's not that difficult and you'll save the £600 (£720 quoted in Sept 2008) odd pounds the stealer wanted to charge me to fix it. Even if your pumps totally buggered you can very easily fit it yourself saving £90 (£120 quoted in Sept 2008) an hour at the stealers.


The content of this e-mail will I hope prompt owners into checking the motor of the hydraulic pump before committing large sums of money to Mercedes-Benz who will want to fit a new pump.
Quote

Hi Lofty Thanks for a great and informative website. Your page with all the input from other owners of Semi Auto A- Class Mercedes saved me about £1000+ or having to trade in my wife's car (which I brought for her) just to fix a problem gear change.
I like so many other A Class owners who's car is over 10 years old had the problem of not being able to get into any gears was facing having to pay large sums to have the problem fixed.
I was told buy one garage a Mercedes specialist that I would nead a new Gear lever selector @ £900 included fitting and Mercedes dealer wanted £99 just to look at it, and another garage said they would look at it but have never done it before.
Well me neither so I decided to do it my self and was in the mind to get a second hand gearbox which seemed to be the cheaper option.
But after stumbling across your site whilst trying to find tips on how to remove the gearbox. I decided to investigate the Clutch Actuator and the changing of the brushes.
I want to give you this link below to put on your website of a firm who specialise in the manufacture of brushes. They have already done 3 or 4 prior to mine and now have registered the dimensions (6.2 mm x 6.2 mm ) in their system so repeat orders can be done over the phone and if you call before lunchtime you should get them the next day.
Cost about £25 incl p&p . They have two outlets one in Croydon and one in the Midlands.
http://www.engineeringcarbonproducts.com/contact_us.php

Thanks again for all your info
Colin

Brushes Availability
Where to obtain the correct size brushes.
www Engineering Carbon Products.com The Order Reference is MB/ACS Brushes x 2 so repeat orders can be done over the phone and if you call before lunch-time you should get them the next day. (UK Only) Cost £21.28 per pair (5/7/10) plus Vat.
We can offer 5% discount off the current list price if 'ACLASSINFO' is quoted.
Carriage is F.O.C.(Free of Charge) in the UK by standard post.
Special next day delivery Monday to Friday excluding Bank Holidays £8.00 extra.
Telephone Tel:+44 (0)208 688 1900/ +44 (0)208 686 7410 Mention 'ACLASSINFO' for a 5% discount when ordering.
Fax:+44 (0)208 688 9913(44)
I would like to thank the Management of this Company for making this concession to my readers. Thank you.


Remove the passenger side wing, very easy as it's just bolted on. Behind it you'll find the pump it looks like a large cylinder with a tube coming out the end and a smaller cylinder on the side. I removed it completely as at the time I didn't know what was wrong with it but I suspect you can just unbolt it so you can get access to the electric motor on the side (the smaller cylinder).
If memory serves there where two screws holding the motor casing on, undo these and pull the casing off to reveal the rotor and actuator.
Look closely at the rotor end which is towards the tube end of the larger cylinder, you should see a sort of structure holding two blocks of copper either side of the rotor.
These are the bushes and in my case these where the problem as they had worn out (after 60K miles!!)

These blocks have a silver wire coming out of them through a cut out in the cage.
As the bushes wear the wire moves along this cut out until it meets the edge of the cage and can no longer self adjust at which point the pump fails.
To remove the bushes carefully prise open the end of their runners, slide them out and cut the silver wire (remembering to leave enough to solder your new bushes to). Surprise, surprise Mercedes don't stock these bushes (not in the UK anyway) so it was off to my local auto electricians who were able to source me a similar set for the princely sum of £10.
Fit in reverse order to removal, being careful with the motor casing, it contains magnets around the inside so it can be tricky to get the rotor end into the casings bearing.
And remember you'll need a soldering iron to re attach the bushes silver wire.

If like me, you remove the pump completely and let all the hydraulic fluid out, a simple way of bleeding the system once the pump was re attached is as follows. Switch the ignition on with the bleed valve open, close the valve and switch ignition off, repeat a few times.


Gear Selector Reset procedure.
If you are having difficulty in obtaining gears then try this re-set procedure:-Published by SVC Sergio, if you would like to join the SVC site member then mail :-svcglobal@svcglobal.com send them you user name with a request to join them and they will return you a password which will enable you to post information and questions.

Sergio posted the following information on MB ACS (clutch-less) and manual gear boxes.
Intrigued with the simplicity of this procedure, he personally did research and found that the suggested procedure does work and due to its importance I felt it would be valuable to owners if I posted it on his site, As we both have a common aim I know he will not mind me copying it to this page.

This reset is a must to those who suffer the old issue of difficulty in getting first and/or reverse gears
ACS
Note Ensure the car is on level standing or chock wheels as necessary
1. Pull the hand brake lever. On
1a. Turn the ignition key on but do not start the engine.
2. Press the brake pedal.
3. Engage the first gear (*).
4. Return to gear lever to neutral (*).
5. Release the brake pedal.
6. Press the brake.
7. Engage the rear gear (*)
8. Return to gear lever to neutral (*).
9. Finally release de brake pedal.
10. Release the hand brake lever, turn off and remove the ignition key.
11. Re-apply hand brake remove chocks

(*)-hear clicking noises coming from inside left front wing

Even with the engine off, the clutch auto system is always energized but in this mode and following the script above, it will learn the correct position of the clutch drive plate.

So, if you let your children play with the gear lever, or even yourself move the gear lever just for fun and without pressing the brake pedal, in the reality, you (or your children or anyone else) are misadjusting all the system.

Remember that this fully computerized electro-hydraulic clutch is very delicate and a complex system, not a toy and should be used only for driving.
Do not ever play with the gear lever and do not allow to anyone to do that, if the engine is off.

For the fully manual system, do the same but, instead of brake pedal, use the clutch pedal.
Sergio.

ACS transmission showing 'F'
In the case of this owner again the 'F' showing on the display, his 'A' class has an ACS transmission, he tried the re-set procedure that didn't help, he therefore consulted a MB specialist and reported back the following information:-
I took the car to an independent Mercedes specialist and they plugged my car into their computer to read off the fault codes.
There were two recent faults on the system in relation to the ACS (Automatic Clutch System). I made sure they gave me a printout off the computer.
P0700-001 – General System Error (Possible Cause: Positron Controller Error)
P1784 – Clutch Defective

They advised that the clutch definitely was defective (it has been slipping recently) however the guy said if it were his car he’d sell it as a new clutch + release bearing they quoted at £1235 inc VAT

So, gives me a bit to think about. I’ve had this car for 8 years and it has been a truly wonderful car, but it is old so I’ll consider my options further.
Thanks again for your help and your excellent website. Interestingly enough after I left the car for a few hours it started working again (no longer displays F on the dash), so I suspect that the P0700-001
General System Error was the one causing the problem and has cleared itself.
I physically couldn’t put the car into any gear so I doubt the P1784 Clutch Defective error was the one making the car display the 'F'
Continued
I really did like this car (the A-Class) and indeed I have had it for 8 years. However after my initial email advising that the garage told me to consider selling the car, I have been looking at new cars and have now set my heart on a particular one which I’ll be buying this week.
Therefore I will be trading the car in, and the dealer has offered me a reasonable price for the A-class. I don’t have any objections to you publishing any content from my emails so please do go ahead if you wish to do so. One thing of note however is that this morning the car displayed the F again (second time now it has done this). The symptoms were as follows;
a) Car displayed F
b) With engine stopped I was able to push the gear lever into every gear
c) With engine started (needed to hold my foot on the brakes to start engine) I was physically unable to put the car into any of the gears.

I tried at least 20 times to start the engine but it always said F. So (with some scepticism) I tried a hard whack on the left wing of the car where indicated in the picture you emailed me and the car started first time without the F.
I must admit I am incredibly surprised that worked, but I would agree that I likely need repair work done to the energiser pump and also the new clutch fitted as it is 10yrs old and definitely worn.


My thanks to this owner for the feed back, slowly we can build up a story of these problems and possible cures but without it we will be left in the dark which is exactly what Mercedes would like. That way our car's live in their workshops and they live of our our hard earned cash.
.
So it appears that if you car doesn't behave, a good beating does do some good!
Joking aside the jolt to the energiser does obviously jar the brushes in the electric motor which for a while may overcome your 'F' display, but in the longer term this unit will need to be replaced or the brushes replaced. Oh and in passing the front wings are plastic so you are unlikely to dent them if you do have to resort to this unique method of curing your car' ills.


While talking about the worn carbon brushes which can well be the cause of the 'F' display on your A CS powered vehicle, I have received the detailed e-mail from an owner in Portugal who has not only managed to repair his energising pump by fitting new carbon brushes But has outlined the procedures so that other owners can do the same I will publish his mail as received and i feel if you are into DIY car repairs you will be able to follow his instructions no problem.


Quote Just to let you know that I have had two bits of good news today; the first is that my CD arrived from you today and second, I saved myself almost £1,000 as I have just fixed my ACS gearbox problem!!!
There was a post on one of the forums (SVC?) explaining how to repair the clutch actuator but I feel as if it needs a bit more expanding as I discovered there were things not mentioned in the post.

I have a 1999 A170 CDI with the ACS gearbox and I suddenly found to my surprise that I could not change from one gear into another. It was as if the clutch wasn’t operating because the gear stick just wouldn’t budge from the gear I was in and I couldn’t select any other gear. Furthermore, I saw the dreaded “F” in the dashboard display! It seemed to point to the clutch actuator not working properly as all the gears seemed to engage when the car was stationery with the engine switched off. After reading another post (on the SVC Global website, I think) about the guy who had the same problem and who decided to investigate, I did the same; after all, what did I have to lose?

First, I disconnected the battery. Then I removed the nearside road wheel, the plastic inner wing lining and then unbolted the plastic front wing. This revealed the ACS clutch actuator unit. It is held onto the chassis with one Torx bolt and then you have to remove the large electrical connector on the top. It is advantageous if you can remove the whole actuator unit from the car. This entails removing the two screws from the clutch master cylinder on the end of the ACS unit. These are those ‘security’ type screws with a pin in the middle and you will have to get the correct tool to do this job.
(
These are best described as Torx screws but with a pip central to the screw which prevents a standard Torx bit from undoing the screw. I have removed these from an old 'Karcher' washer so they obviously use the same sort of screw.
More information: www.brycefastener.com,

In fact, nearly every fixing on this unit is of the ‘security’ type. Marlins, B&Q or Halfords should be able to help with a set of these tools. Don’t worry about removing the clutch master cylinder, you will not lose any clutch fluid; the master cylinder will just come away. It just locates onto a push-rod that disappears off inside the actuator.

Now you can take the whole clutch actuator to a workbench. The bit that will more than likely be the cause of the fault is the little electric motor on the side of the actuator. My car has done 119,000 miles and so when I removed the aluminium end piece that locates the electric motor (two screws that screw into the actuator housing) and then the long cover that encases the electric motor (two screws), I saw that the two carbon brushes had worn right down and were hardly touching the copper commutator of the armature. There are springs which ensure that the brushes are in good contact with the commutator but if the brushes have worn beyond a certain point, they will not be able to touch the commutator because the copper ‘tail’ from the brush is hard up against the brush holder and prevents the brush from moving any closer to the commutator. DO NOT attempt to remove the armature; leave it in place!!!!

The first thing to do is to remove the old brushes. Cut the copper ‘tail’ just before the soldered joint with the hard wire which is to the side of each brush. Next, you have to break off the bit of plastic that stands up directly behind the back of the brush. This will give you access to the brass insert in the plastic brush holder assembly. With a small screwdriver, prise open the two brass lugs on each brush holder and take care to catch the springs which will whiz out! Then you can remove the old carbon brushes.

Next, you will need two new brushes. I got mine from an auto electrical shop. They were made by SPAMO and the part number is: JAAX19. SPAMO’s email address is: spamo@libero.it
These brushes are fractionally larger than the ones you need (originals are 6mm x 6mm x?) but as they are carbon, they can be filed down to size very quickly and easily. Just ensure that they are a nice easy fit inside the brass brush holder. These brushes also have the copper ‘tail’ coming out of the back instead of the side but it doesn’t really make any difference. You will have to be the judge of how long to actually cut them as they are far too long to begin with. Just make sure that they are long enough to still be able to get the spring in behind them. If you cut them too long, you will not be able to do this, and if you make them too short, the brushes could wear out again prematurely. If I’d had more forethought, I would have measured them for you!! Sorry! You will also need to file a radius on the end of the brush so that it mates with the commutator accurately. For this job, I took a fine strip of emery paper and looped it around the commutator. Then I got an able assistant to apply a little bit of pressure on the end of the brush whilst I drew the emery paper backwards and forwards. It wasn’t long before the brush was a perfect fit on the commutator.



So, once the brushes are the correct size and fit, slide them into the brass brush holders, put the spring in behind them and close over the two small brass lugs. It’s a bit of a job as you will find the springs keep on wanting to escape! Persevere and all will be well!! Make sure you keep the copper ‘tails’ uppermost so that they can slide along the gaps in the brass brush holders during their lifetime. Next you have to cut the copper ‘tails’ to length and solder them to the bits of hard wire beside the brush holders. Nearly finished!!

I then wrapped a couple of turns of insulating tape around the brush holders just to make sure that there was no way the back of the brush holder could ever touch the metal of the motor casing. Don’t forget, that we had to break the small bits of plastic that used to do this job for us. I then put a little bit of lithium grease on the end of the armature’s shaft and refitted the motor casing. Make sure that it fits snugly and do up the two casing screws. On the actuator body, there is a black plastic circular bung which is in line with the commutator end of the armature. You should remove this bung (lever off with a screw driver) which will reveal the other end of the armature’s shaft. You should be able to put a small Allen key inside this shaft and turn it to ensure that the armature is free to turn. Leave this bung out for the minute.

Next, replace the aluminium end piece with the two screws that secure this item to the actuator. Then refit the complete actuator to the inner wing. When you try to replace the clutch master cylinder assembly, you will probably find that it won’t go on. This is because the armature has ‘unwound’ and needs winding in again. Whilst one hand turns the Allen key in the end of the armature shaft, the other hand can offer up the master cylinder to the actuator. If you are turning it the right way, the master cylinder assembly should move closer and closer towards the actuator until it is snug up against it and you are in a position to get both fixing screws in and tighten them up. You can now replace the black plastic bung.

All that remains to do is to replace the electrical connector on top of the actuator, the plastic inner wing lining, the front wing and the road wheel. Connect the battery up with the side light switch on to negate any surges to the ECU, reset your windows and the BAS/ASR light (by going from lock to lock with the steering wheel) and take it for a test ride!!! You may hear some whirring and clicks from inside the front wing but this is all quite normal as the unit self adjusts and resets itself.
Unquote
You can imagine how chuffed I was that just a days work and £5 for a pair of carbon brushes have saved me at least a £1,000 at the main stealers. Good Luck!
Kind regards,
Paul
Paul many thanks for the detailed instructions, I'm sure they are like so much of the information on this site it's going to save many owners a lot of money and in some cases the car's, because there does come a point where garage repairs amount to more than the car is worth and then sorry to say it's good by car, when in fact a bit of DIY will prolong the life of what is an other wise perfectly sound vehicle. Paul has offered his mail address in case owners should want more detail on a particular aspect:- e mail:-paul@mahonyaviation.com



You may also find information on this site which is useful to you forwarded by Andre' www.automatikoelwechselsystem.de. it does appear that some information is in English,



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