clutch fluid flush

[DMC-Ron]

One of my auto buddies lent me a brake fluid tester. It's essentially a conductivity meter that indicates the concentration of water in the brake fluid. It actually seems to work and it's not very expensive. While testing the DeLorean, the brake reservoir indicated OK with less than 1%. But when I tested the clutch reservoir, it really lit up. Made sense because I flushed the brake system when I put in a new master about a year ago, but I have never touched the clutch system. So now I'm reading the various threads about the clutch master/slave. It looks like a PITA but doable. My concern has to do with a tech page comment (see link below):

One other thought…. When is the last time the fluid was changed, and when was the last time the master and slave cylinder was changed? If it has been a long time, in about 3 months after you flush the fluid one or both of those cylinders will start to leak. New fluid seems to have that effect on a car where it has not been changed for a while.

http://www.dmcnews.com/Techsection/clutchbleed.htm

Is this pretty accepted wisdom ... that if you flush a clutch system that has not been maintained, the master and slave will begin leaking in a few months? It looks to be an even larger PITA to replace the clutch slave, hence my dilemma and concern.

Ron

[Bitsyncmaster]

First time I flushed my clutch, it leaked at the slave about 2 weeks later. The master lasted about 10 years but recently I replaced that.

[David T]

The brake fluid gets sludgy and thick so it won't leak as easily. The fresh stuff will leak. Especially since you confirmed the brake fluid was "wet" so you can assume the insides of the cylinders are corroded and the seals are torn. Another reason the clutch fluid goes bad, the brake fluid gets heated and that helps to drive the moisture out. The clutch not as much. Replacing the clutch cylinders is a pain and it is expensive. That is why I have been recommending flushing the brakes AND clutch systems every other year. Fluid is cheap and a lot easier to do than cylinders.

[gerald225]

I'm sorry to hijack this thread a little but I have been having fits since I replaced the clutch line and slave cylinder. After what I'm sure is thorough bleeding the slave cylinder only moves the fork about 1/4 inch and the clutch does not disengage.

I want to start a new thread but I cannot see where I can do this. I have been a member of DMCtalk for several years but have only made a very few posts and I am a junior member. Can junior members not start new threads?

I would appreciate any help I can get, particularly how to start a new thread.

Thanks, Jerry

[David T]

When you log in there is a button on the top of the page "Post New Thread". As for bleeding, it can take several attempts to get all of the air out. Especially if you use the "vacuum" method (sucking the fluid out at the bleeder on the slave cylinder). I prefer the "pressure" method, Stepping on the clutch pedal and opening the bleeder to let the air and fluid out and then releasing the pedal.

[AirmanPika]

As for bleeding, it can take several attempts to get all of the air out. Especially if you use the "vacuum" method (sucking the fluid out at the bleeder on the slave cylinder). I prefer the "pressure" method, Stepping on the clutch pedal and opening the bleeder to let the air and fluid out and then releasing the pedal.

Having just did this I agree. I did a mix of both. My clutch system was bone dry thanks to the failed slave (and being disconnected for a year). I realized just using a vacuum pump was taking forever so I started pumping the pedal until there was resistance and keeping mindful to keep the reservoir filled. Eventually fluid entered the tube and started flowing into the catch cup so I started using the vacuum pump to ensure no more air was exiting. Once content I closed off the bleeder (to my cramped hands' chagrin) and all was good. It's admittedly been about 10 years since I changed the fluid (when the master was replaced) and the slave is new so we will see if any leaks form.

Also...I am assuming you pulled the transmission to do the slave work so I am curious...did you check to ensure the throwout bearing was properly slotted onto the fork when reinstalling? When I was reassembling everything the first time I luckily caught that somehow the bearing had come off of the fork. If its now off and stuck between the clutch and the fork I can see this causing the issue you are having (if I am picturing the mechanism correctly)

[Ron]

I'm sorry to hijack this thread a little but I have been having fits since I replaced the clutch line and slave cylinder. After what I'm sure is thorough bleeding the slave cylinder only moves the fork about 1/4 inch and the clutch does not disengage.

I want to start a new thread but I cannot see where I can do this. I have been a member of DMCtalk for several years but have only made a very few posts and I am a junior member. Can junior members not start new threads?

I would appreciate any help I can get, particularly how to start a new thread.

Thanks, Jerry

Click HERE to see a list of the Main Forums. Clicking on any of them will take you to a list of Sub-Forums and/or a list of Threads. There are "+ Post A New Thread" buttons on the Left near the Top and Bottom in every Forum.
Junior members can start a new thread anywhere except in the For Sale/ Wanted Section, which has a different set of rules (listed there).

PostNewButton.jpg


Feel free to PM me for help/questions.

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I prefer the "pressure" method, Stepping on the clutch pedal and opening the bleeder to let the air and fluid out and then releasing the pedal.

I think he meant, "stepping on the clutch pedal, opening the bleeder to let the air and fluid out, closing the bleeder, and then releasing the pedal."

[DMC-Ron]

First time I flushed my clutch, it leaked at the slave about 2 weeks later. The master lasted about 10 years but recently I replaced that.

Dave,
Did you rebuild the slave or replace? And were you able to remove/install without removing the transmission?
Ron

[Bitsyncmaster]

Dave,
Did you rebuild the slave or replace? And were you able to remove/install without removing the transmission?
Ron

I first did the bleed without any rebuilding and it leaked a few weeks later. I then removed and rebuilt the slave by pulling the mixture unit out to get at it. That rebuild lasted without leaks for 10 years but then I thought I had a clutch problem and replaced both master and slave just as a precaution.