SL/R230: Brake Fluid Change-Old Fluid Looked Like Pentosin CHF 11S!
Thread Starter
Senior Member
Joined: May 2019
Posts: 280
Likes: 37
From: Lincolnshire, IL
2005 SL55 AMG
Brake Fluid Change-Old Fluid Looked Like Pentosin CHF 11S!
Hi folks. Decided to do a brake fluid exchange today, which I know doesn’t get everything due to the SBC. However, when I emptied the old fluid out of the reservoir, it sure looked like fresh Pentosin CHF11S instead of old DOT+. Has anyone ever seen or heard of anything like this before? Is this what Pentosin Super DOT 4 looks like? I find it hard to believe that the previous owner would’ve knowingly put in the wrong fluid. Looks like I may be headed to my Indy for a full Star flush since I don’t have access. Thanks in advance.
Last edited by poppyboy; May 9, 2020 at 08:48 PM.
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Joined: Jul 2012
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From: Orbiting the planet
This place is a joke.
I see it all the time. The brake fluid turns green after several years. It's not ABC fluid. The factory interval is to flush it every 2 years. I suspect the green may be some type of algae.
Power steering fluid is a hydraulic oil (hydrocarbon). Brake fluid is a complex ester (different chemical).
The seals in brake systems are not designed to withstand hydrocarbons.
Power steering fluid is not designed to withstand the very high temperatures that it can be exposed to in brake calipers.
Thread Starter
Senior Member
Joined: May 2019
Posts: 280
Likes: 37
From: Lincolnshire, IL
2005 SL55 AMG
Thanks. I knew that green fluid couldn’t be considered normal. FWIW, I did put in DOT 4+ at each corner until most of the green tint was gone, but obviously there’s still plenty of the old stuff in the system. Calling my Indy tomorrow morning. They only work on MBs, so I’ll have them hook it up, flush it out and assess.
