Happy New Year to everyone.
I am trying to flush the brake fluid , I am fairly familiar with the procedure, ( or am I ? ) ...logging onto Alldata I see the following in the procedure:
- Actuate the Master Cylinder Switchover valve. ( see attached diagram ) . Could someone explain that to me please? I thought we just hook up the power bleeder, set the PSI 15-20 PSI and thats it.
- Also, it says to pressurize the system to 2 bar, thats 29PSI, is that a mistake, I thought we couldnt go over 20 with our cars, I am not even sure that the cap which came with the bleeder can hold 29PSI.

Advise and comments are always welcomed and appreciated. Regards,
Max

 

Hey Max,

I flushed my AMG brake system using the power bleeder. Don't need to open any Master Cylinder Switchover valve. Just fill the bottle with one liter of brake fluid, (I use ATE super blue brake fluid) it take about one liter to flush the systems. DOn't let the bottle run dry or you have to start over. Than pump it up to 2 bar like it said, about 30psi. and start bleeding the lines; right rear, left rear, right front and left front.

If this is the first time you flush the E55 brake lines than one or more of the bleeder screws might be rusted out, clogged. My front left was clogged and rusted, i had to remove it completed and unclog it. Pretty basic and very easy.

 

On your Brembo GT's?

 

Thank you Peter, thats exactly what I did, then something went wrong and I went back to reading the and alldata. By the way, not that it should make a difference but I am flushing my newly installed Brembo GTs fronts and back, and I am using Brembo Fluid 600. Using the Motive power bleeder, I did exactly what you described, but I guess now I thinking that the special cap I bought with it couldnt hold the pressure above 15-18 PSI. And even with that pressure I had to repump it twice for every wheel, meaning it couldnt hold the pressure to do all the wheels at one time, ( that part I can live with). First time I pumped it while at the rear right , I had quite a mess on my hands all over the master Cylinder !!!! I also read that unless you have good pressure one wont be able to flush the fluid from the ABS system. Now my thinking is the cap must be defective, thats the only explanation, because I looked everywhere for that switchover valve and couldnt find it and it was never mentioned in any posts about the W210, so it must be a mistake on the ALLDATA downloads. Thank you again, it looks like I have to do it again with a better designed cap.
Happy New Year to you and all our friends .
Max

 

BTW, for anyone else reading this who is bleeding brakes, if you read many posts you will find ( Do not exceed 20PSI ) , that is not true. I think they say that for protection or the crappy plastic caps supplied with many bleeders . I can confirm that 20 PSI is not enough for flushing( at least for the W210 AMG, ) . I waiting to get a new and better MC cap, but I bet the 30 psi as Mercedes lists is more like it.

 

No, on my factory AMG brake. I flush they system when I install the AMG cross drilled rotors. Carnutz custom install the Brembo GT and they pump the brake padel to bleed the Brembo.

They play with high end car like Mercedes, Porsche, BMW, Aston Martin, Lambo they even have a Koenisegg CCX in the show room and the don't own a power bleeder i was worry they might wear out the brake switch

 

Sweeet!! Show us some pictures

 

Peter did they have a special reason for doing it without the Power Bleeder? I know that stoptech advocates the old fashion way also..while Mercedes intstructs to power bleed !!

 

Not using a power bleeder may leave you with a spongy pedal.
The old school pump the pedal will not move enough fluid at a fast enough rate to over come the vertical rise in the brake lines coming out of the ABS unit (air remains trapped). Secondly it is necessary to use a power bleeder at the 2 bar, 29 psi to open the check valves in the ABS unit as well. For the people that claim the old school worked fine, that is because they never had any air in the system, however if air is introduced you will defiantly need a power bleeder. My dealer introduced air in to my system and after a year with a spongy pedal I bled the brakes 4 times the old school way with no improvement in the pedal feel, then I gave in to the power bleeder, all good now. Don't do as I did.

 

Installer told me this way was fine, he did it to all the car with no problem. I ask him if he can use the power bleeder and not pump the padel and he they don't use power bleeder

 

This is true..on my way home it feel spongy, worst than stock but 45min of stop and go traffic on the way home it firmed up like they said.

 

Yachtmaster, I am so glad you chimed in, it was an old response you posted which alerted me to the problem of not enough pressure, too bad I didnt see it earlier, but at any rate, the cap I got wasnt going to hold 29 psi to save its life!! Onto finding a proper cap, ...Ultimate garage has some nifty looking ones for sale for $15...these guys know something or two...so I am getting that one.

I think I am going to build my own thing , there has to be a better way ...great aluminum cap with the right gaskets, an air pressure regulator, hooked up to an air compressor, that should be easy, now I am thinking of how to implement the tank to hold the fluid . You can do all the above real easy if you are just bleeding, but flushing is slightly different.

 

When I Worked at Mercedes they use a special bleeder that holds several gallons of brake fluid...It has a Metal screw on cap for the fluid tank
We bled brakes at 2Bar with no problems

For Home I set the regulator to 2bar on the air compressor with a good water trap and use a MB Metal cap fill the brake fluid tank and bleed one corner at a time...PITA but it works

SBC cars are different

 

Hey Mark,
Pardon me but what are SBC cars? and what is a water trap? excuse my ignorance! By the way, I did finish the front bearings and everything sounds and feels fine ...so far! Thanks for your support and guidance.

 

SBC was entered into The Mercedes Brake system on the W211/R230 and Maybach Sensotronic Brake Control (SBC) Mercedes dropped SBC in 2007 on model update W211s

Water trap is a MUST when you have a Air Compressor ..It prevents moisture from getting in the Item you are using the compressed air for..

As ANY Moisture in the Brake System will cause damage

I Use a Basic trap then a filtered trap ..yes 2 to prevent moisture

 

You see Mark, its giving these kind of responses that get you in trouble !!! Makes it very hard for me not to keep bothering you !!! LOL.
Best regards

 

Max you did everything correctly, use 2bar of pressure, with a pressure bleeder, ensuring it doesn't run empty. Your only mistake was using that flimsy plastic bleeder adapter cap. Find a better anodized aluminum one. Snap-On has one for about $60, but I am sure there are cheaper ones out there. Make sure it is snugged down tight and work your way around the car, starting at the right rear, then the left rear, right front, and finishing with the left front. And don't forget to use jackstands when you have the wheels off.

Nick

 

Using the old fashioned brake pedal pump method is a bad idea.
You're moving the piston way beyond its normal operating tolerance. Debris seems to build up over the exposed area and consequently has the potential to mess up the seals. I've seen this happen on numerous occasions.
It may or may not happen. I just think with a car like a Mercedes, don't take a chance and pressure bleed it.

 

Thanks Nick, I am on the quest for the right cap.

 

I didnt mean for that thread to be that long , but it will be great to hear from the interested and knowledgeable people. I used the Bleeder from Motive which seems to be the defacto when it comes to DIYers, bar shop or mechanic ones, it might be OK even though it is plastic but I heard several concerns and complaints about the MC cap, it seems to the culprit. I have sent mine back and we ll see what they say. I also started thinking of making my own, using a regulator, and air from the air compressor with the right cap...I found this car from Ultimate garage :

http://www.ultimategarage.com/shop/p...oducts_id=2123

With this setup , as Mark rightly corrected me , one would need a water trap/ filter , to remove the moisture from the air flow coming the compressor , that can be found from several sources , from $25-$80. If the cap from Ultimate garage is as good as it needs to be, that setup should be great.

Then I found this product:

http://cgi.ebay.com/ebaymotors/ws/eB...#ht_500wt_1399

I emailed the gentleman ( aerospace engineer ) who designed it and now fabricating it, and he seems quite nice . what I like about his design , is its simplicity, and it does seem to be very well made. He also said that the biggest problem is in the cap itself, making it pressure tight is very important which I agree. His uses a O ring seal (? ) .While several sites claim that pressure needed is 15-20 psi , our cars and I would imagine several others need 29-30 psi. My concerns about his design is :

- Using air from the tire. He claims that if used and connected properly, one can bleed four corners with a loss of 0.5 psi to the tire!!! ( I have nt verified that of course). But even if that is true, then what about moisture, I know that air compressors do in fact introduce moisture in the air tank, but what about the air from the tire? The designer states that the air in the tire is dry.

- That design may work well for bleeding , but what about flushing? I dont know the exact capacity of his canister ( I will get that ), if it is not big that means that the system will be opened up again to refill , releasing the pressure, and even if it was big enough , will it hold the pressure long enough for a flush job?

I still think his design is elegant and simple, the fittings seem very well made. And if we could verify few things , maybe there is some interest in a group buy. I might consider being the first one to try it, and report , but I would to hear your comments.