Clutch Master Cylinder Replacement

After all these years of dealing with a leaking clutch master cylinder, I decided to finally replace it. It is incredible how different the clutch feels now. Like a new car. I replaced the slave cylinder with a new one years ago. The pin under the pedal box is what deterred me from replacing it before.

The Ferrari OEM master clutch cylinder is about $450. The after market ones average $200. I bought mine from Ferrari of New Jersey for $175 plus shipping.

Here is what I did:

1) Remove the front driver’s seat. It is only 4 Allen screws.
Hint: Put a nice padded matt in the floor; you’ll be spending some time down there. You will only be able to use one hand to get the pin out. Be patient.
2) Remove the brake pedal spring that is covering the cotter pin.
Hint: Use a string to pull on the hook of the spring towards the rear of the car and a needle plier to unhook it from the chassis.
3) Remove the cotter pin with the needle plier.
4) Push the pin with a screwdriver or the end of the needle plier. It will not go all the way through as it will hit the top of the clutch box.
5) Slide the end of the rod to the side, spin it and the pin will come out.
6) Now go to the trunk and remove the hose at the master cylinder side. I held it up with a tie wrap so the fluid would not drain out.
I believe the Mondial 8 has its own reservoir.
7) Remove the top and bottom nuts that hold the master cylinder. In my case, I used a large adjustable wrench from my plumbing supply toolbox. I had to remove the stop light switch to fit the large wrench.
8) Pull out the master cylinder. In my case, it was very rusted after years of leaking, I had to hammer it out and use a file to remove the corrosion on the aluminum box.
9) The master cylinder was very corroded. I did not want just replace the O rings, so I ordered a new master clutch cylinder.
Note: I bought the o-rings from Guido, but after seeing how bad the cylinder actually was, I decided to buy a new one.
10) I measured the distance from the base of the old master cylinder to the center of the hole where the pin goes. See the picture below, top one is the new. I then removed the bracket from the old cylinder and placed it on the new one with the same distance.
11) Installed the new master with standard M8 nuts tightened by hand.
12) Went back under the pedals. Checked that the hole on the pedal bracket matched the hole in the master. I had to remove the master and readjust, it was off slightly.
13) Installed the master with two new stainless steel lock nuts.
Note: I could not find 12 mm M8 nuts so I could use a socket. So I got new 13 mm stainless lock nuts and used the big wrench again.
14) Placing the pin back in is the tough part as it has to be done with only one hand. I used one hand to guide the pin in. I used a coat hanger wire with the end bent in an L-shape to push the pin in from the top.
15) The cotter pin was easy to place. Bending it was not easy as the pin spins.
16) Put the brake pedal spring back.
17) For the bleeding, I removed the plate behind the rear seats, easy to access the bleeding nipple. I use Prestone Dot 3 Synthetic.
18) Bleeding was longer and harder than expected. I used the hand held MityVac and also pumping with the pedal. It took over 1 pint of brake fluid and there were still bubbles. Pressure started at 2” of travel., there was enough travel to disengage the clutch, but it was low. The next day I went to work with the car, it took about 15 minutes of stop and go traffic to get the pedal back to the top.

Good luck!
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Hi Guido.

I started with the MityVac hand bleeder. Very little fluid came out. I then switched over to my 12 qt MityVac oil changer and pumped until I ended up with similar vacuum from the hand held one. Lots of vacuum to spare. Even though, not much brake fluid came out.

What I do not understand is where the obstruction in bleeding is. The hose from the brake reservoir has a large opening. The hole from the tube to the master cylinder is also quite large. The tube from the master cylinder to the slave is large. The slave has a standard bleeding nipple. Brake fluid should flow easily.

I am very happy now with the way it handles now. I am even thinking in readjusting the pedal so it does not engage so high. Granted, next time I remove the seat. ;-)