removing slave cylinder

Reinstalled the rebuilt cylinders. No leaks, but could not get the system bled conventionally, even with help from my mechanic neighbor. Listened to Birdman and got a Motive power bleeder. Worked liked a charm on both the clutch and brakes.

Everything back together, but.... with the circuit bled, I still have a BIG problem. I am only getting about 8 mm of displacement at the slave (should be 20.5 mm). I made sure to measure the prior master cylinder adjuster rod and reinstalled with the exact same dimension. That is the only adjustment available in the system. How can I be that far off? I was able to disengage the clutch prior to having the hydraulic failure. I am stumped!!!

Anyone adjusted their Mondial clutch before? Should the rod be shortened (that is what I believe)? If so, what is the ratio of mm shortened at the master to mm of stroke added at the slave? Can it be done with the pedal box in the car?

I am including views of the slave and master from the workshop manual.
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I remembered that I have the old seals from both the clutch master and slave cylinders, so I measured both. The slave bore is approx. 22 mm and the master is approx. 18 mm. So the area ratio is very close to 1.5X, with the slave have the large cross-section. In other words a 1 mm stroke at the slave requires a 1.5 mm stroke at the master for equal displacement of brake fluid. That means that for an equal volume displacement, if I am looking to increase the slave stroke by 12.5 mm (20.5 mm spec minus 8 mm actual), I need to increase the master cylinder stroke by nearly 20 mm. I know there isn't that much adjustment in the master cylinder adjuster, and I definitely wasn't that far off in reassembly.

Anybody have any clue as to what I am missing????? This is driving me insane!

 

Issue was that I could not get rid of all the air in the clutch master cylinder. It is impossible to bench bleed it and then install it onto the two mounting bolts and the rigid hydraulic line without losing enough fluid to drain some fluid out of the master and create an air bubble.

The answer is....install the master in place and tighten everything (the 2 mounting bolts, and the hydraulic line). Do NOT install the fill tube, plastic fitting or rubber grommet that would connect to the brake master reservoir. If you look down into the bore where that hose would attach, you will see two small ports, with the front one having an ever smaller counterbore (see representative picture). Using a small hypodermic filled with brake fluid (I used a No. 27 needle, which has a 0.016" or 0,4mm outer diameter), insert it carefully into the small counterbore (you do not want to scratch the bore of the master cylinder), and slowly inject fluid into that port. You will see bubble form and come out from that port. Continue until you raise the fluid level above the small holes. Stop and pump the clutch pedal a few times and repeat, until you no longer see any bubbles coming out of the small port. It took me 3 times, but I now have a clutch and the car has been driven. Yahoo!!!!
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I removed and reinstalled the clutch master on my 82 Mondial 8 without pulling the clutch box.

As noted above do need shaved socket to get bolts loose.
And the clip and pin holding the rod to the sector is a PITA to get to when it is in the car.

Wire brushing the slave cylinder pin with a dremel tool to knock off the scale makes it alot easier to remove.

Frank

 

What were the symptoms of needing the clutch master cylinder changed???

 

Leaking cylinder with grinding in all gear changes..

 

Thanks. My mondial's clutch is slipping all the time and the slave cylinder is leaking, so my first step is to rebuild the slave cylinder.

 

Howdy all, I pulled my slave cyl to rebuild and it has corrosion so a little hone work isn't enough. Is there a cross reference for replacing the whole part? So far my search hasn't turned anything up.

 

Reviving an old thread.

I may need to replace my clutch master cylinder as bleeding lasts only a few days. There is a small leak.

How did you guys access the pin underneath, over the pedals? Did you remove all the springs first? I cannot get my fingers or any tools to properly access and remove it. Or should I unscrew the adjustment shaft instead and leave the pin installed?