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!

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.

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

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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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.

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

whunter@pelicanparts.com

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