Jump to content


Photo
- - - - -

Bleeding Clutch!


  • Please log in to reply
11 replies to this topic

#1 westlin

westlin

    Mini Mad

  • Members
  • PipPipPipPip
  • 281 posts
  • Location: Chelmsford

Posted 04 July 2014 - 03:50 PM

Im struggling to get the clutch mechanism to work correctly. Im working on a 91 Cooper. I have replaced the slave cylinder and the resvoir as far as I can tell is fine. The piston in the save cylinder appears to be fully out and the push rod to the clutch fully in ( well up to the nuts).

ive tried pushing the cylinder rod in and bleading but as soon as I let it go it just slowly slides out.

Am I doing something wrong or do I have an issue somewhere else.

Help please

#2 westlin

westlin

    Mini Mad

  • Members
  • PipPipPipPip
  • 281 posts
  • Location: Chelmsford

Posted 11 July 2014 - 01:38 PM

Im at a loss to the cause of the problems with my clutch. Ive now replaced the seals in the clutch master cylinder but still there is very little movement in the clutch pedal or the slave cyclinder. I can't see any leaks or bulges in the pipe. Its the spring in the slave cylinder that is pushing it out. I've tried bleading with the pedal pushed to the floor before locking off and with pedal not touched.

Help please

#3 dklawson

dklawson

    Moved Into The Garage

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPipPipPip
  • 10,923 posts
  • Name: Doug
  • Location: Durham, NC - USA
  • Local Club: none

Posted 12 July 2014 - 11:48 AM

"The piston in the save cylinder appears to be fully out and the push rod to the clutch fully in ( well up to the nuts).  ive tried pushing the cylinder rod in and bleading but as soon as I let it go it just slowly slides out."

 

If original, your car will have the Verto clutch.  I have no experience with that mechanism as my car is much older.  I am confused by your statements above.  It sounds like you are expecting the clutch slave cylinder piston to retract when the pedal is released.  There is no mechanism to make that happen.  If the piston retracted on its own after each use of the clutch the pedal would have excessive travel the next time the pedal was depressed.

 

What exactly is the clutch not doing correctly?  The reservoir is just a holding vessel for brake fluid, it's the master cylinder that does the work.  Is it (the MC) able to pump fluid when you are bleeding the slave?  If you leave the slave piston alone such that it is "out" is the Verto lever arm moved by the slave when you depress the clutch pedal?  Lastly, what "nuts" are you talking about about ("...well up to the nuts" )?



#4 westlin

westlin

    Mini Mad

  • Members
  • PipPipPipPip
  • 281 posts
  • Location: Chelmsford

Posted 12 July 2014 - 12:02 PM

When the bleed nipple is open and the peddle pressed I get fluid out with no problems. The peddle is solid when pressed and there is no movement in the slave. The nuts I mention are the adjusters on the end of the clutch spindle, where the clutch lever is connected.

I have just bought another mini and the peddle moves freely and the slave pistion is seen to move.

re the return I thought that the piston would have some movement back caused by the return of the peddle.

thanks

#5 westlin

westlin

    Mini Mad

  • Members
  • PipPipPipPip
  • 281 posts
  • Location: Chelmsford

Posted 12 July 2014 - 12:33 PM

Here is a picture of the slave cylinder, the piston is at the end of its travel. The pedal has about an inch of travel and I think that is just play.

Attached Files



#6 dklawson

dklawson

    Moved Into The Garage

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPipPipPip
  • 10,923 posts
  • Name: Doug
  • Location: Durham, NC - USA
  • Local Club: none

Posted 12 July 2014 - 04:54 PM

Sorry, there is nothing to drive the slave piston back so the fact that it is "forward" is normal.

 

As I mentioned earlier, I have no first-hand experience with the Verto clutch or its components so I can only speculate on what is going wrong.  I am curious about the throw-out arm the slave is connected to.  Looking at your photograph, it appears that the arm is "all the way down" and contacting the stop nuts.  If the arm is all the way down, it cannot move the throw out rod forward to release the clutch.  My gut feeling is that if you remove the clevis pin securing the arm to the clutch cover... and remove the arm you would find a broken arm, a bent arm, or a damaged ball on the end of the arm (or even a combination of these things.  Wear on that ball is a significant contributor to limited clutch travel on the pre-Verto clutches and probably is on the Verto clutch as well.  Replacing the arm and rod as a pair along with the clevises throughout the mechanism typically helps restore pedal height and travel.

 

I am posting a picture below that shows where the Verto arm should probably be in relation to the stop nuts on the rod.  Compare it to the components shown in your picture and see if that isn't where the problem is.  (The pictures below are not mine, they belong to others and were found using Google. )

 

The second picture is for a new arm where the ball end is still fully spherical (not worn flat) and the ball end is not "bent".

The final picture is the rod the arm goes into.  The side hole is where the ball end of the arm goes.  If the ball end of your car's throw out arm is worn, the mating rod with side hole is also likely to be worn.  If you have to buy a new arm, buy a new rod at the same time and replace the clevises as the same time.

 

Sorry, the board software won't let me embed one or more of the pictures directly.  Click on the links below to see them.

 

The first picture is the Verto clutch arm relative to the stop nuts on the rod.

http://i61.photobuck...18012009001.jpg

 

The second image is for a new Verto arm with a full spherical ball end and the arm is not bent.

http://minisport.com...timage_1340.jpg

 

The third image is of the rod the arm goes into... the rod that supports the clutch release bearing.

http://www.minispare...350/DAM1955.jpg



#7 westlin

westlin

    Mini Mad

  • Members
  • PipPipPipPip
  • 281 posts
  • Location: Chelmsford

Posted 12 July 2014 - 06:14 PM

Not quite as round as the new one (see pictures). From memory and it was some time since I touched the engine before it went back in the pin had a nice big grove in it and I replaced it for a new one.

looks like the need replacing then

Attached Files



#8 olly33

olly33

    One Carb Or Two?

  • Members
  • PipPipPipPipPipPipPip
  • 758 posts
  • Location: Midlands
  • Local Club: 42nd Street (back in day)

Posted 12 July 2014 - 08:23 PM

Or blob a bit of weld onto the ball end to make the distance up, to just try, to see if it solves it.



#9 westlin

westlin

    Mini Mad

  • Members
  • PipPipPipPip
  • 281 posts
  • Location: Chelmsford

Posted 13 July 2014 - 07:03 AM

Having now looked closely at the lever there is alot of wear under the ball ( you can just see it on the photos). Looking in the haynes manual it looks like that is what reduces the travel and because its not there it goes alot further. If it ever stops raining and I can get to my welder ill try welding the missing element back on and re profiling the arm.

ill keep you posted.

#10 westlin

westlin

    Mini Mad

  • Members
  • PipPipPipPip
  • 281 posts
  • Location: Chelmsford

Posted 13 July 2014 - 03:05 PM

Right, the rain has finally stopped, welder put in to practice. I've reformed the ball ( as best I can) and the tapered shaft and finally the clutch lever has movement. Still alot of slop but at least it points at a replacement lever.

thanks for your help guys.

#11 dklawson

dklawson

    Moved Into The Garage

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPipPipPip
  • 10,923 posts
  • Name: Doug
  • Location: Durham, NC - USA
  • Local Club: none

Posted 13 July 2014 - 06:18 PM

If there is still a lot of motion and clearance between parts, you need to buy the new arm and rod and while you are there replace the clevis pins.  It won't cost a lot and it should make a big difference.  Regardless, I'm glad you were able to get some motion in the arm by reforming the ball.



#12 olly33

olly33

    One Carb Or Two?

  • Members
  • PipPipPipPipPipPipPip
  • 758 posts
  • Location: Midlands
  • Local Club: 42nd Street (back in day)

Posted 13 July 2014 - 08:10 PM

The wonders of a welder, wish I had one and could weld. At least you know the cause now.




1 user(s) are reading this topic

0 members, 1 guests, 0 anonymous users