Lowest price for W210 ABS unit

[johnmc]

Hi Folk,
Anyone know the best source to get a replacement ABS unit for W210? Merc won't help with the repair.

My ABS unit just packed in, spookily at the same and in the same manner as Olav Maxwell's and similar faults reported here. The leak pumped all of the brake fluid out in under 8miles of driving! Dual circuit was no help whatsoever. Pedal was on the floor after just a couple of spongey presses on the pedal.

When we discussed braking techniques using ABS/BAS etc the other week were right to base our braking on the assumption that when you hit the pedal none of it works! Pumping the pedal and driving safely got me back home.

This is an unsafe failure, happens fast and if on the motorway you could be in big trouble, never seen anything like it, and I would never expect neglectful design like this from Merc. This should be a recall, in my view.

Thanks for any leads on a supplier for the pump, moan over for now!!

Have a nice weekend!
John

 

[television]

Hi John we had a guy here who fixed his own recently if its a leak why not have a go

 

[johnmc]

Hi Malcolm,
Hmm! Hadn't occured to me, why not indeed! It does look like a seal has gone somewhere on the ABS unit.

I'll take a closer look in the morning.

John

 

[television]

Dont forget John that this is a Bosch unit, you may be able to scrounge a bit from Bosch

 

[Schtum]

Hi Folk,
Anyone know the best source to get a replacement ABS unit for W210? Merc won't help with the repair.

My ABS unit just packed in, spookily at the same and in the same manner as Olav Maxwell's and similar faults reported here. The leak pumped all of the brake fluid out in under 8miles of driving! Dual circuit was no help whatsoever. Pedal was on the floor after just a couple of spongey presses on the pedal.

When we discussed braking techniques using ABS/BAS etc the other week were right to base our braking on the assumption that when you hit the pedal none of it works! Pumping the pedal and driving safely got me back home.

This is an unsafe failure, happens fast and if on the motorway you could be in big trouble, never seen anything like it, and I would never expect neglectful design like this from Merc. This should be a recall, in my view.

Thanks for any leads on a supplier for the pump, moan over for now!!

Have a nice weekend!
John

I'm sorry to read about this John; and I really don't like reading about major brake failures, that come out of the blue!

Can I ask the mileage of this 210; also has the fluid been changed every two years?

I hope you get it sorted soon.

 

[johnmc]

Hi Schtum,
The car is 7 years old, 56,000 miles only. The fluid has been changed per the service schedule. I suspect it wouldn't make any difference. Think about it. If you designed a car on the basis that the brake fluid had to be changed to prevent a key seal failure would you trust the design? That's a dependency that could get a designer into jail.

I reckon it's a design flaw. The ABS controller is fine, but the pump is kaput!
Early failures are usually down to bad design. I'll put money on a worn seal inside the unit somewhere, question is can it be fixed? I'm also concerned about negligent design as a dual circuit braking system collapsed, no redundancy.

I'm waiting to hear from Merc before I strip it down, and I'm escalating the problem to try and get some funding. Price fitted is 1,300Quid!

I've also had a hunt around for exchange units, but so far they are only exchanging the ECU sections.

Good tip again Malcolm, I feel a letter to Bosch coming on. If I don't hear anything this week I'll bypass the ABS and get it moving again, and strip the ABS pump.

I'm pretty angry about this one. Family likes running around in the German tank, but not without brakes...! I've had ABS issues on a previous car sensor failed), but never lost the brakes totally on anything in 26 years of driving.

Bye!
John

 

[MIW615]

Try contacting your local dealer to see if they can supply parts so you can overhaul your unit.......................

Lochrin Autos Ltd .
19 Lochrin Place
Tollcross
Edinburgh
Middlothian
EH3 9QT

Phone 0131 229 8304

or write to the head office at ....................

Robert Bosch Limited, SEU, PO Box 98, Uxbridge UB9 5HN

 

[anyweb]

yeah go to a local breakers

here's a w210 being broke near me in sweden

http://www.thomassonsbilskrot.se/pap/visa.php?id=260056

and the price list

http://www.thomassonsbilskrot.se/pap/priser.php

ABS hydraulaggregat 300 kr
ABS sensor 150 kr

kinda cheap if you ask me
cheers
anyweb

 

[wireman]

Brake fluid will atack the seals if you do not change it, the degradation due to heat and water absorption changes the fluids characteristics and it will eat seals, thats why they change it regularly.

I have had failures of brake seals which have gone all soft and gooey due to lack of this essential maintainance proceedure, although the fluid was about ten years old on the fire engine that I first saw a catastrophic failiure on.

In the case of the fire engine (a Bedford TK) the service manger found himself jobless, the master cylinder seals had softened in their seats and rolled over during an emergency stop causing total loss of braking effort just when it was needed, somewhat surprisingly there was no evidence of there having been a brake failiure, after the incident the service brakes were found to be fully functional. Only during investigations to help the driver retain his permit (and avoid prosecution) did the fault come to light.

The moral of this tale is change your brake fluid and do it now if you dont know how long its been in there.
If your master cylinder is older than ten years it may be prudent to change that as well.

 

[Schtum]

I agree with wireman. I've seen brake fluid go like Porridge if its not been changed for years! Think of the back pressure that would cause.

BTW. It was very old Daimler DS420 that had Porridge for brake fluid. Cool motor, sh't brakes...

I change mine on the bike, every year.

 

[Laughing Gas]

Hows about this one?

There's an ABS pump on sale on eBay
http://cgi.ebay.co.uk/Mercedes-W210...tcZphotoQQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Good luck!

 

[johnmc]

Thanks Guys,
Interesting comments, I have changed the brake fluid on time, last time in fact 6,000 miles/one year before the failure. The handbook doesn't talk about seals, but refers to the loss of braking power as the fluid ages. I'm sure if it said, you'll avoid a costly pump or master cylinder replacement then people might pay more attention. I've never understood why an important item like this is left optional on car services. It should be included no matter what. I'm amazed the Government ain't spotted that issue yet for accident prevention.

As before, I always benchmark to other cars that I've owned. I have never had a brake failure on a car before where the fundamental braking power all vanished. It's got nothing guys, can barely stop it at 10mph. I would not expect to have this kind of problem on a maintained car at 56kmiles, especially a Merc. Something is wrong. I can find another 3 vehicles with the same issue on this forum alone.

Anyway, I still don't know if it's a seal or more serious issue with the pump. It could easily be something else. I got a reduced price for the repair, and will go ahead with it. Once it's fixed I'll strip the old one, see what the score is. I didn't want to start on that until I knew what my options with Merc were. I will take some pictures of the stripdown and post them if you're interested? Might help others fix their own.

I appreciate your pointers to used parts, but I decided to go with new parts. If this fault happened again on the Motorway the consequences could be very bad. If I was trading it in right now I would have taken the chance, but a few hundred quid versus lives? Not a choice really. My wife is upset about it, lost her confidence with the car.

Thanks again!
John

 

[kth286]

johnmc

I assume your car has traction control - yes ???

You did the brake fluid change yourself ????????????

Is there not a special proceedure for the ABS/traction control system that must be followed, and which you may have been unaware of......a little knowledge and all that !!!!!!!!!!!!!!!!

 

[johnmc]

Hi David,
Fuid change was all done be the Merc pros at great expense. That's why I'm miffed! I'm done nothing to this car myself, but the brakes are still busted, and dangerously so. I'm very unimpressed. All the ABS, EBD, BAS totally useless.

Since the last posting I've been able to talk to several mechanics, including one from a Merc dealer in Glasgow, and he reckons the whole brake fluid and seal theory is nonsense. In 30 years of working on cars he's never seen any evidence of brake fluid causing a seal failure, and reckons something broke inside the ABS unit. Materials used on modern cars should not be causing a problem. He's seen cars with no fluid change in 10 years sail through their MOT, for what that's worth. The fluid should be changed every two years to reduce the risk of it boiling under braking and reducing brake force, and that's it.

With any luck I'll know the answer this week when I strip the pump.

Bye!
John

 

[television]

I have to agree with your engineer that is all very true

 

[johnmc]

ABS Pump Stripped

Hi Folks,
I've stripped down the defective ABS pump. It's a pretty basic thing, three main elements, see the picture:
- Motor, top left.
- Plastic housing with copper strips, movement actuators for some hydraulics in the main housing.
- Single piece cast housing with multiple actuators. The fault is inside the casting somewhere. The actuators are all intact, there's no evidence of a leak around that area. The leak came from a pressure relief valve on the other face of the casting. If you look closely at the copper actuators (cylinders with copper tops) you'll notice that the two at the top left have some evidence of burning on the face.

I reckon that there's been a fault that's caused an overpressure in the system, perhaps a stuck actuator. In the week before the failure I did have an emergency stop in the wet, to avoid a deer running across the slip road near Livingston on the M8, and it could be that some of the actuators have no reset properly. There's no seals, every item in the casting is threaded and pinned in place.

The casting where the leak happened has no maintainable parts. The ABS electronics are in another module. There's no chance of repair other than getting a replacement assembly, new or used.

Does Bosch definitely make this item, or only the electronics module? I've no idea if I have a claim or not. I might write to them with some pictures and ask for an explanation of their attempt to kill me..!

There you go! Car is running again. Time to trade or keep it going? Who knows!

I have to say Merc's service was pretty bad. Took them 5 days to get me a quote and a decision from Merc on the price "we're too busy". I must have taken them by surprise then. I agreed a price, then when I turned up to pay they tried to charge me the full whack without the £300 discounts! Took an hour of arguing to settle up. Total rubbish service for the money, and I regret every £ I gave them for it. That's enough to put me off on it's own. It's bad enough having a problem without the hassle to fix it at that price.

Regards,
John

 

[television]

Thanks for posting back, yes Bosch do make them

 

[OlafMaxwell]

It was interesting to see this come up again. I can vividly remember this failure and it is exactly as described, as if the leak occurred because the pump went onto auto and pumped out all of the fluid. My car has always had full MB service and had fluids changed etc at due dates. At the time the unit was about £600 ex VAT and I got a 50% rebate. With that the final bill was about £600. However it cost Mobilo much the same.

At the time I argued the cars should be recalled but it fell on deaf ears. The danger is that the warning came on at which time the brakes were already gone. However there are more cases out there, I know of some in US too.

 

[wireman]

There is a definate risk to the seals if the fluid is not changed, if not why does very old fluid go black? The answer is disolved rubber seals.

I have seen many brake parts taken off older less well maintained cars in which the seals were of the consistency of a wet fruit pastile and the brake fluid was as black as the old engine oil from a diesel. It is because of this type of potential catastrophic failiure that legislation to fit dual circuit brakes to all vehicles with 4 or more wheels was enacted many years ago, whith this legislation came a masive fall in brake hydraulics faliure related incidents.

I wont be taking any car of mine to a fitter who thinks leaving old fluid in is OK, in fact I would not let him fit a dustbin lid.

Granted the occasions when these faults cause serious trouble are quite rare but the risk involved is just to great.
The water absorbed by fluid reduces the boiling point by a large amount for only the slightest quantity of water, there is nothing to be done about this other than to change the fluid regularly.

Modern disk braked cars do not suffer from catastrophic wheel cylinder seal failiures in the same maner as older drum brake systems did. The clearances in the slave cylinders were much greater than the clearances in disk calipers and the goo into which seals are converted (by old fluid) does not extrude through the gap between the piston and bore as easily mostly due to much shorter travel making the problem in wheel cylinders much less common than in older systems.
The master cylinder remains as a long travel device and failiures of this are just as common as ever.

I like others who have commented on this thread am staggered by the fact that seal failiures in the ABS unit can lead to an unsignaled fault leading to loss of braking on both supposedly isolated braking circuits.

Am I wrong in thinking that the maker has failed in a duty of care in allowing such a system the be used on a road vehicle?

Some may think that I am writing a load of bollony, to those I would say remember this lot and let it go through your mind in that ever so long but realy so short piece of time between you realising that you can't stop but the scenery can stop you.

 

[television]

Thank you for taking the time to write that out, and it makes good sense to me.