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Dirty Hydraulic Fluid

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fwtexasbj8

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I have just changed all the flexible hydraulic lines in my clutch and brake system on my BJ-8 trying to get ready for our first road trip of the year. I also replaced the master and slave cylinder on the clutch side. I have bled the brakes with no problem but when I bled the clutch, I am getting what appears to be black, dirty fluid out of the slave cylinder. I have flushed the system with nearly 3 pints of new fluid but it still looks like it has come from somewhere with badly deteriorated rubber seals or flex line. I have let the fluid that I extracted sit for a couple of hours and I do not notice anything settling out. Has anyone had this type of problem with new components? I guess I could have gotten an old component that had the rubber already bad, but am at a loss on what to try next besides try to replace one or all of them again. The fluid was not discolored when I broke the system down so I do not suspect a corroded steel line. Any ideas???

Doug
 
Hi Doug, Never had that problem. However, try replacing the old rubber clutch line if it is serviceable for the new one . also look at the fluid in the clutch section of the fluid reservoir and see if it is dirty. Fwiw--Keoke
 
Doug--

You didn't mention whether or not the clutch was funtional--moving the lever arm--before and after the bleeding or whether you replaced the seals in the clutch cylinders.

If the answer is no to to all then perhaps the rubber you are seeing is from the seals and they are continuing to deteriorate. Also have you checked for debris in the fluid reservoir?

When flushing and replacing hydraulic fluid I alternate between the ATE blue and clear fluid as it makes it so much easier to know when you have got the old stuff completely out.
 
I am using the old formulae Castrol LMA fluid like i always have.

Michael, the clutch was workiing fine when I started. The reason I broke into the system was the flex line to the right front brake was leaking so I replaced all the brake flex lines. I only went into the clutch when I found the master cylinder alos leaking. I thought I was doing the best thing and decided to replace all the clutch hydraulics, master and slave cylinders and the flex line, with new components while I had everything apart. I am going to take Keoke's advice and try to reinstall my old flex line and see if that clears up the fluid.

Thanks for your help and advice.
 
Here is the latest. I drew some fluid from the clutch section of the reservoir this morning and the fluid is clear and debris free. The brakes bled clear with no discoloration at all in either the reservoir or at the bleed nipples. I also broke the connection between the steel adn flex line and the fluid there was already black. This seems to indicate to me the problem is upstream of the flex line. I bled another pint through the system with no improvement in clarity.

Are there any rubber seals in the bottom of the reservoir that are separated from the brake section and exposed to the fluid? The reservoir is about the only part I did not replace. I had the system "dry" for about a week while I waited for parts but would not think anything could dry out and rot that fast but the residue really seems to look like a deteriorated rubber part.
 
IIRC there isn't any rubber in the reservoir. From your other investigation, the only thing left would be the clutch master cylinder.
 
Greg,
That is what my diagnosis is too, even though the master cylinder is brand new also. I am going to talk to Moss before I tear it open but I suspect the seals are bad.

Thanks for the help.
 
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