[W126 Coupe] Brakes and air

[Jay Hirsch]

On "normal" cars,  to me which is  most American cars if the power  
booster  has  a "leak" the brake is very hard or firm,  and stays  
that way the more you apply pressure, something we all wish at  
various times
Will not comment on the 560  power booster but  assume all brake  
systems are the same....spongy pedal either air  in the line or  
fluid  leak some where.
Do not know why you  do not try the simple and fool proof way of  
bleeding lines

Jay H
On Dec 19, 2010, at 1:05 PM, Ronny 560sec wrote:


> Jason,

> I thought that when there is a vacuum leak the brake pedal will  

> stiffen! Or am I wrong.

> Meanwhile I will ask my mechanic to check that line too.

>

> Ronny

>

> --------------------------------------------------

> From: "Jason Mavris" <mavris2 at comcast.net>

> Sent: Saturday, December 18, 2010 9:43 PM

> To: "Mercedes Coupes Mailing Lists" <mbcoupes at mbcoupes.com>

> Subject: Re: [W126 Coupe] Brakes and air

>

>> Don't know if this has been mentioned. By I suspect that the Brake  

>> Booster Vacuum Hose is cracked and this is the cause of your  

>> problem.  You might check that line. They generally crack right at  

>> the oval part on the line closet to the master cylinder. If its a  

>> hair line crack the brake pedal will go to the floor.

>>

>> Jason

>> ----- Original Message ----- From: "Ronny 560sec"  

>> <ronny.geenen at verizon.net>

>> To: <jhodgman at gmail.com>; "Mercedes Coupes Mailing Lists"  

>> <mbcoupes at mbcoupes.com>

>> Sent: Saturday, December 18, 2010 5:18 PM

>> Subject: Re: [W126 Coupe] Brakes and air

>>

>>

>>> My mechanic replaced today also the master cylinder of my 1987  

>>> SEC and used this time the newly bought Motiv pressure bleeder.

>>> The brakes became firm. They did a test drive and first it start  

>>> holding. Then they asked me to test drive the car. And when I  

>>> started I felt directly the soft pedal that went all the way down  

>>> slowly. Even pumping did not help.

>>> Since this is happening again I think the master cylinder was OK.  

>>> And they have used about 2 gallon of break fluid.

>>> Any idea and advice

>>>

>>> Ronny

>>> Glendora, California

>>>

>>>

>>>

>>> --------------------------------------------------

>>> From: "Jonathan Hodgman" <blueridgemb at gmail.com>

>>> Sent: Thursday, December 16, 2010 10:27 AM

>>> To: "Mercedes Coupes Mailing Lists" <mbcoupes at mbcoupes.com>

>>> Subject: Re: [W126 Coupe] Brakes and air

>>>

>>>> Given the age of the master cylinder in Most of these cars,  

>>>> pressure or vacuum bleeding is the way to go.

>>>>

>>>> Also, there are times when air gets caught up in the ABS pump.   

>>>> I've found that cycling the key a few times as each wheel is  

>>>> bled eliminates any trapped air.

>>>>

>>>> Jonathan

>>>>

>>>>> The MB Coupes Website!

>>>>> W126 SEC Mailing List

>>>>> Postings remain property of MB Coupes, L.L.C.

>>>>

>>>>

>>>> -- 

>>>> Jonathan Hodgman

>>>> Blue Ridge Mercedes/AMG East

>>>> http://www.blueridgemb.com

>>>> Offering Enthusiast Service, Restoration and Tuning.

>>>> (404)805-1357

>>>> 96 S600 Euro

>>>> 94 E420 (Parts)

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>>>> 91 560SEC ECE

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>>>> 90 300SL

>>>> 88 300E AMG

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>>>> 88 560SEC AMG Euro ECE (Parts)

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>>>>

>>>> The MB Coupes Website!

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>>>> Postings remain property of MB Coupes, L.L.C.

>>>>

>>> The MB Coupes Website!

>>> W126 SEC Mailing List

>>> Postings remain property of MB Coupes, L.L.C.

>>>

>>

>>

>> The MB Coupes Website!

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>> Postings remain property of MB Coupes, L.L.C.

> The MB Coupes Website!

> W126 SEC Mailing List

> Postings remain property of MB Coupes, L.L.C.