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I have flushed the hydraulic fluid for the clutch several times.  It stays clean for a while and then starts to accumulate black stuff in the reservoir.  The clutch master is new.  This leaves the stainless flex line and the McLeod hydraulic throwout bearing as possible sources.  Both of those are 25 years old but I do not see any fluid leaks.  It looks like something is coming undone.  Can the 32 inch flex line produce this?  Otherwise it would be o-rings in the hydraulic throwout bearing.  The clutch is working perfectly.  Any ideas?  Thanks.



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The master cylinder is not from a Pantera vendor.  Notice the square reservoir.  It is by Centric and is for an Alfa, but it also works on Panteras.  I think there are just a couple of o-rings in the clutch master.  In the morning I will check around the pedals for fluid.

I know that some of the replica Pantera clutch masters leaked at the reservoir joint.  That is why I have this one from Centric.  I also recall that the current batch of Pantera replica clutch masters have an improved grommet and no longer leak at the reservoir joint.

Clutch master fluid turns black when the master seals are going bad. I bought a new master one year ago, reservoir has leaked since day one and after 500 miles of driving my fluid is turning black. I will be requesting another exchange. Fwiw, clutch slave is also leaking after 500 miles. Not sure who is making these garbage replacement parts. Frustrating doing things over and over.

Clutch master fluid turns black when the master seals are going bad. I bought a new master one year ago, reservoir has leaked since day one and after 500 miles of driving my fluid is turning black. I will be requesting another exchange. Fwiw, clutch slave is also leaking after 500 miles. Not sure who is making these garbage replacement parts. Frustrating doing things over and over.

A year ago my other Pantera got the clutch master that leaks at the reservoir.  When I bought it I already knew it would probably leak.  I fixed it by swapping reservoirs with an old clutch master.  No more leak and it looks fine.  It does not release black residue into the fluid at this time.  The photo below shows how it looks in the car with the old non-leaking reservoir in place.



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My hunch is that all of the vendors get their replica clutch master cylinders from Wilkinson.  He said his new batch does not leak at the reservoir.  There was not any mention about the seals and bore.  As I said above, the seals/bore from his prior batch are working correctly in my case although it has only been a year and usage has been light.

I will be replacing the master with the black stuff that is pictured at the top of this thread with one of his new ones in about a week and will update this thread with the outcome.

I have the new clutch master cylinder in hand and can see that the leaky reservoir issue has been resolved.  The reservoir now feels like it is solidly attached and is similar to the factory units that shipped with our cars.  I will be installing it in the next several days.  Hopefully it fixes the problem with black stuff in the fluid for a long time.



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I hope you're all using Girling recommended Castrol LMA DOT4 fluid???

If not, OLD DOT3 could be simply collecting moisture and what you're seeing is metal oxide?   Newest DOT3 fluids may likely be synthetic now.

The Castrol LMA  ("low moisture absorbing" ) will tend to be darker in color with time, but we're talking a long time.... has always been synthetic near as I can tell, for some 25 years, as long as I have been working on my of the first jobs I had to do because ALL of the cylinders were absolute useless crap from previous owners using DOT3!

You're supposed to flush your brake/clutch fluids out every once it a while too...........????   Suction old out of the reservoirs, fill, then flush out the lines and calipers etc via bleeders....refill as needed.......


If you are replacing like with like and can retain the same push rod, the job may become much easier.

John Buckman and I swapped out my all-aluminum CNC clutch master with its identical SS-lined cylinder replacement in the parking lot of Los Laureles lodge some years ago during Monterey car week.

did everything from the front trunk, did not remove the driver’s seat, did not bleed the system afterwards. Absolutely no issues at all.

and yes, we were surprised it was that easy and that successful  

you never know until you try



From this post, it looks like I was sold a clutch master cylinder with seals that break down and fail. I installed it a couple of months ago and the fluid started to turn dark in about a week without even driving the car. I am going to take the master cylinder that was removed from the car and send it to a place in New York that can rebuild it with quality parts.

Funny , I have same issue, I have what I think is a billet Master, the fluid is turning black, I flushed it a few times and now is black again, my clutch pedal goes soft if I push it to quick. Just ordered a new Clutch master and slave from PI Motorsport, hope they dont have same issue. I will strip the old clutch master and take pics when the new item turns up.


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Steve - any updates? How does your fluid look?

I just received/installed another clutch master (my 3rd in a year), and flushed the line. The current part does look better (normal) for the bottle to body joint and is still dry after a month!!!! However, the fluid is turning dark after less than 100 miles. I could see hints of darkening after the first 20 miles of driving.

Some say it does not matter, but to me it is a sign of something happening with the seals??!!  I'll drive mine a bit more and empty/refill the bottle and see if it continues to pollute the fluid.

Rob, all,

OK, I don't recall what my clutch fluid looked like 4 months ago....not even sure that I checked!   SOOOO I checked today, and my fluid is "dark brown" but not black.  No goobers or floaty bits, just maple syrup!

We have a fairly humid environment here, and I wanna say that this is "normal" absorption of water????  I have a cast iron master clutch cyl also, which could be contributing.  Now, I haven't flushed this since I worked on all of this some 2-3-4??? years ago....bad me...I know......barely drove the dang car..... vehicular abuse...!!!!

I will be suctioning this brown out, and replacing with new Castrol DOT4 before trip to Reno!  Maybe flush out the cylinder if I get cooperation......    Will also check fluid in brake M/C which I DID flush completely when all 4 corners received new seals (stuck pistons!!!)  and the M/C got a tear down only to find nothing amiss there!

I hope this helps.....!

My new clutch master failed. The fluid seemed to be turning black so I flushed it a couple of times. Then I took it on a fairly big outing to Full Throttle Panteras open house. The fluid was perfectly clear when I started the trip. About halfway through the trip during some spirited driving the clutch master begin to fail.  When I held the clutch down, it would gradually release itself.  I was able to complete the trip and make it back home but maneuvering in parking lots was very difficult.

After arriving at Full Throttle, I inspected the fluid and it was very black. The next week I removed the failed master and showed it to Wilkinson and explain what happened. He asked which brake fluid I used and I said it was DOT3. He said it has to be DOT4 and set me up with a new one. I have that in the car now. So far so good, but time will tell.

DOT 3 and 4 are "supposedly" the same other than 4 having a higher boiling point and being less hygroscopic.  But some info suggests that older systems do not "like" 4 and you should use 3 only.  I have used 4 in my car for many years now.  The brake fluid tends to "yellow" with time - been 3 years now since I last changed/bled it.  The clutch fluid seems to stay clearer and not yellow as much (why I have no idea) but occasionally I do get black stuff (not pieces but just a black slime).  My clutch master is probably 20 years old and my slave is a CNC I bought from Dennis Q. at that time.  The clutch works fine so I have just sucked the black fluid from the reservoir and refilled it and then bled the system.  

Once you have been in the Pantera community for a number of years, it becomes obvious to just about everyone that the advice from our vendors is not something that can be taken as absolute truth or always correct.

sadly, most of them will argue till they are blue in the face trying to convince you that you are wrong.

been there and done that, more times than I should have


Larry - LOL - thanks - I needed that chuckle! I have been at it for 1.5 years so I'm still a rookie!

The funny thing is, it is not like we are having a problem with a precise part like a fuel injector. These are simple parts! I am also on my 2nd replacement slave cylinder - that one was leaking after a few hundred miles.

Yet, the Corvette brake master cylinder in my car, which probably saw 100 miles of use in the past 10 years of prior ownership, hasn't polluted the new fluid (DOT 4) for the 600 miles that I have put on the car.

I am convinced it is garbage seals and/or nasty rough bores that are causing this. I can't see DOT 3 or 4 having an effect, ever, or even in a matter of weeks??

Last edited by Rob Fridenberg

Albanygt40 - my opinion - I think the masters carried by all of the Pantera vendors are coming from the same supplier (boxes look like they are from China??)?? Given the crazy low volume of this vehicle, I can't imagine that multiple suppliers are running this part with the hope of making any money.

FWIW - someone at the supplier finally mastered (copied) the technical challenge of attaching a plastic bottle to a fitting that doesn't leak. So at least there has been some improvement!

Last edited by Rob Fridenberg

The seal used in the stock type Pantera clutch master cylinder is a type of o-ring, not a "cup".  As such, the o-ring can only tolerate a very small interference fit to the master cylinder bore, something like 0.002".  Rebuilding the master cylinder by honing the bore and replacing the seal usually results in an early failure because the honing increases the cylinder's bore which reduces the interference fit with the o-ring.  

The fluid turning black is caused by extremely small amounts of material being removed from the o-ring  during normal cycling of the clutch master cylinder's piston.


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