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What's this gunk inside the brake fluid reservoir?

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It's your Throw out bearing. Clutch and brakes share the same reservoir and brakes get alot hotter than the transmission needs to.

Separating the and having a dedicated reservoir for the clutch will solve the issue usually.
 
39
28
Exp. Type
HPDE
Exp. Level
5-10 Years
Atlanta
It's your Throw out bearing. Clutch and brakes share the same reservoir and brakes get alot hotter than the transmission needs to.

Separating the and having a dedicated reservoir for the clutch will solve the issue usually.
Crud I was hoping that wasn't the issue. Reading threads now about divorcing the clutch and brake reservoir.

Should I be worried about the bearing now? I haven't noticed anything weird with the transmission.
 
Crud I was hoping that wasn't the issue. Reading threads now about divorcing the clutch and brake reservoir.

Should I be worried about the bearing now? I haven't noticed anything weird with the transmission.
I would divorce it as soon as possible, it isn't cost heavy or super technical, but I doubt you have to worry about replacing the throwout bearing at this point.

I would wait until convenient but keep an eye on the pedal feel.
 

TMSBOSS

Spending my pension on car parts and track fees.
7,529
5,242
Exp. Type
HPDE
Exp. Level
10-20 Years
Illinois
Castrol fluid can deteriorate soft parts. I lost the clutch master cylinder after 8 years with the Castrol. To help protect the slave cylinder of the throw out bearing, use a different fluid for the clutch system. I put the Ford Dot 4 in the clutch. This saves you bucks when flushing the brake system since they will be separate.
 
179
308
Utah
Over the winter I put in a separate clutch reservoir for the reasons mentioned. It was my brake fluid that was being contaminated by the clutch for sure. After one event, my new clutch reservoir fluid was already getting darker, and my brake fluid looks better than ever.

I used the following on mine. Worked great. There are lots of options but I thought I would put this out there:


Mine is an S197, but some will mount the reservoir on the edge of the fender just inside the engine compartment where my remote damper reservoir is.

I used a vacuum plug and spring clip to plug the nipper on the brake reservoir.

IMG_7371.jpeg
 
39
28
Exp. Type
HPDE
Exp. Level
5-10 Years
Atlanta
Thanks guys, seems like this issue isn't talked about enough. I decide to go with the GM reservoir #92065790 and got a master cylinder from a auto car so I won't have to worry about the nipple.

Will update when I get that installed. Besides a lot of flushing any tips to get all these bits out of the system?
 
Thanks guys, seems like this issue isn't talked about enough. I decide to go with the GM reservoir #92065790 and got a master cylinder from a auto car so I won't have to worry about the nipple.

Will update when I get that installed. Besides a lot of flushing any tips to get all these bits out of the system?

Turkey baster what's in there out, fresh fluid and flush. Which since you are getting an auto reservoir (I did the same) it's a must anyways.

Pretty straight forward. I think this issue used to be talked about more, just kinda died from the front pages so to speak.
 
1,119
1,110
Exp. Type
HPDE
Exp. Level
5-10 Years
Lenoir City TN
Thanks guys, seems like this issue isn't talked about enough. I decide to go with the GM reservoir #92065790 and got a master cylinder from a auto car so I won't have to worry about the nipple.

Will update when I get that installed. Besides a lot of flushing any tips to get all these bits out of the system?
Once you separate out the clutch circuit and change to the auto reservoir, a good brake flush should get rid of the gunk out of the brake system. Like someone else mentioned above use dot 3 in the clutch system going forward. The Castrol SRF doesn't seem to play nice with the slave cylinder.
 

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