Brake fluid discoloration

[Kenneth Gear]

I recently had my brake reservoir replaced and flushed and bled the brake fluid.  

Before doing the wrok I noticed the brake fluid was black.  Now within a couple of weeks of having the work done, and without having driven the car more than a mile, the fluid in the rear side of the reservoir is black again.. the front-brake-end of the reservoir is the correct color.  

What is causing this?  (FYI..I have stainless steel brake lines)


Ken G
1971 280 SL
Silver/red

[Malc]

This sometimes comes from the caliper, master cylinder  seals and or hoses. When you say you have stainless lines I assume you mean the pipework. Have you changed the flexible hoses recently??

You do get "crud" building up and you may have to flush the system a couple of times buy pumping fresh fluid through. Seems like a waste of fluid, but it's really the only think to do without taken it all apart.
Malc

[Kenneth Gear]

yes the pipework in stainless.  So if I understand correctly the discoloration is from the rubber peices deteriorating?  Is that correct?



Ken G
1971 280 SL
Silver/red

[Naj ✝︎]

We have some 'clever' garages and main dealers in this country who would change the fluid in the resevoir only and charge for flushing the whole system.  
Can you trust your mech? Maybe the rears were not flushed.

naj



65 230SL
68 280SL

[Kenneth Gear]

Good point

Ken G
1971 280 SL
Silver/red

[J. Huber]

Just a related suggestion for all. The flexible brake hoses should be changed fairly regularly (every 4-5 years or so I think). They can look fine but be cruddy inside. And they are not expensive so if you cannot remember the last time -- I'd change 'em.

James
63 230SL

[waqas]

What about metal brake lines? Is there a test to find out when they should be replaced? (mine look somewhat corroded on the outside)

Download Attachment: brakeline.jpg
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Waqas in Austin, Texas

[graphic66]

Those are definitly pitted and the hose looks old too. It looks like that rearend is out. I think you should definitly replace those before installation. You could also clean and paint the axle before installing the brake lines and have a sharp looking unit.