Round Goby

Is there a way to unscrew the brake bleeder screw on both front brake calipers on a 2004 Mercedes Benz E500 4MATIC?

I couldn't used 6,7 or 8mm wrench to unscrew the "nipples" as the edge are curved/smoothed out. I have tried to used other tools, include the one the clamp tightly, but it wouldn't unscrew the nipples. I have owned the car for two years and it was time for the brake fluid change. The rear nipples used 11mm wrench.





I am following BrianS's DIY Brake Fluid Change: https://mbworld.org/forums/w211-amg/...id-change.html

Other helpful thread: https://mbworld.org/forums/w211-amg/...s-w-o-sbc.html

With a little more research, I have found this "Replace Brake Fluid" procedure for this vehicle: http://www.justanswer.com/uploads/eu...rake_fluid.pdf

I wish I had read that procedure beforehand as some tips were helpful.

I did not realize I needed to connect the charger to battery. While using my STAR DAS to bleed the brake, it was incomplete due to low voltage. I only bleeded rear calipers today and couldn't do the front as I was unable to unscrew the "nipples". I will connect the charger to main battery next time when bleeding the brakes. I am using Motive Bleeder as well.

Also, is there a need for Electro Hydraulic Brake Adapter? See the bottom of the page: http://www.brinsonco.com/store/page16.html

Yes, safety is my number 1 priority and it should be yours too!

I would appreciate any help/feedback. Thanks!

Plutoe

That tool you referenced is for repair shops that do not have access or know how to use the DAS Xentry(what you call STAR DAS) that you used to relieve the SBC system so you can work on the system.

Very strange that the nipples are rounded, I believe that Sears has a tool that was designed for use in your rounded application!!

Ichabod

Sometimes you can drive one down onto the bleed screw (or whatever other very small nut has gotten rounded) and it will get a good enough grip to turn it out, but you'd better be ready to install a new bleed screw when you get the old one out. I suspect that hammering down the TORX socket is a major factor in breaking the screw loose from its corrosion bond so that comes out.

Quadcammer

pipe wrench or vice grips should do it, then replace the bleed screw.

PelicanParts.com

I agree
Living in Michigan corrosion, this is common.
I have several selector boxes full of new bleed screws to replace the damaged ones.

whunter@pelicanparts.com

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Round Goby

Very interesting ideas guys. Thanks for contributing. I thought I had to replace the whole front calipers, when you can just replace the bleeder screws. This might be a dumb question: Say, if I am not using Motive Bleeder to apply pressure, will brake fluid still leaks out if I can unscrew the rusted brake bleeder screw as is and replace it with a new one? Will it be a problem? Air? I can always fill up if it leaks during replacement.

Plutoe: Looks like I don't need that EHB adapter. I believe I rounded even more when I attempted to open it with 7mm wrench then 6 mm wrench. I believe the bleeder screws are rusted into the calipers. I found this link: http://www.denlorstools.com/autoblog...eeding-brakes/. They are asking me to use the heat it, which I try to avoid. I may use the PB Blaster or WD40, then try to unscrew it with vice grips. I actually tried to use vice grips and it wouldn't unscrew.

Ichabod: Great idea. I only have E8 torx socket, to change the Crankshaft Position Sensor. I can buy a set of torx sockets no problem. Hammering it down to break the corrosion bond. I am thinking of trying that.

Quadcammer: I tried to use vice grips on both side brake bleeder screws. It just "spin" around as the nipples are curved and no longer like 6 sides/hex. I suspect screws are corroded into calipers.

PelicanParts.com: I live across the border from Michigan. Never knew winterized salt conditions can lead to corrosion damage to brake bleeder screws. I just realize my calipers are all rusted. I would like to buy 4 piece of brake bleeder screws. You say you sell them? Does anyone know the part number or which brake bleeder screws fit my vehicle or Mercedes in general? I see some univeral screws on ebay and amazon, but not sure if it is exact fit.

PelicanParts.com

Bleeder valve
MB# 0004212865
http://www.pelicanparts.com/cgi-bin/...2865&x=13&y=13

whunter@pelicanparts.com

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