Hydraulic Fluid Leak

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randall977
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Hydraulic Fluid Leak

Post by randall977 »

I've been reading through quite a number of threads relating to the brake system but I'm a little confused as to what I'm dealing with...

There's been a long term leak of red fluid from the part next to the brake master cylinder but I'm not quite sure what this part is? I'd like to repair it but again, am unsure what kit I need or if it's available. Many thanks for your patience and any advice!

Brake-Booster.jpg
Brake-Booster.jpg (324.43 KiB) Viewed 4029 times
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Brucey
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Re: Hydraulic Fluid Leak

Post by Brucey »

it is the brake servo (booster) and it is probably leaking ATF because either

a) the pushrod seal is knackered and/or

b) there is some kind of obstruction in the fluid return line which means the return pressure is higher than normal

There are posts on this site and others detailing how the booster comes apart and how to fix it. IIRC the pushrod seal is held in a plastic housing which itself is sealed to the servo bore via an O ring. Provided the plastic housing isn't cracked both the seal and the O ring can be changed for just a few quid.

hth

cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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randall977
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Re: Hydraulic Fluid Leak

Post by randall977 »

Many thanks - I will investigate it further...
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JCS
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Re: Hydraulic Fluid Leak

Post by JCS »

Randall,

For the Brake Boosters, I have a Rebuild service.

Here is a link page to my 14 websites, on big coupe
Just follow the directions in RED to view the captions,

I NOW HAVE A NEW WEBSITE, Link : www.jaysbmwparts.com.
Please save as a Favorite
NEW e-mail LINK : [email protected]

Then go to #1 boosters

Best,
Last edited by JCS on Sun Oct 31, 2021 11:05 pm, edited 1 time in total.
Jay
'88 M6, Red/Tan
My NEW Website https://www.jaysbmwparts.com/
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randall977
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Re: Hydraulic Fluid Leak

Post by randall977 »

Thanks for that, brilliant write up and photos!
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