So if your driver's side carpet looks like this:
Then you have a couple of choices:
Buy a new clutch master cylinder, or re-build the one you've got.
I know they're not expensive, but I wanted to keep the stock unit and see what was involved in re-building it. So I bought this:
The kit comes with the piston, spring, rubber boot, retaining clip, an O-ring, and a white gasket (Which I did not use cuz the stock unit didn't have one.)
Begin by draining fluid out of the system. (After you jack up the passenger side and use a jackstand 
) Safety First!
I drained the system from the dampener block, which I removed later:
Then remove the master cylinder cap. The link between the master cylinder and pedal is a pin/cotter pin connection, shown here:
Remove the cotter pin and pull the pin out.
Then move to the engine bay.
Disconnect the hard line from the master cylinder with a 10mm line wrench here:
Then remove the (2) 12mm nuts holding the master cylinder in.
Here:
And here:
Now you can pull the whole unit out and begin disassembly:
I was going to replace the rubber boot but since it was not the source of the problem, I did not. I sprayed the linkage with a little paint to be able to put things back together exactly how they were if I chose to take it apart:
I had the "black sludge in the reservoir syndrome" so I cleaned that first.
Before:
After:
There is a retaining ring/ clip that holds the linkage in. I used a pick and some needle nose pliers to remove it:
Then I got to see the leak up close:
There is a set screw at the bottom of the master cylinder that needs to be removed to allow the piston to come out. It is a standard screw seen here:
Once the screw is removed the piston will come out on it's own because of the spring pressure:
Remove the piston/ spring combo and begin cleaning the whole assembly with brake cleaner. The O ring that is supplied with the kit is for the base of the set screw. Change it out. Then I lubed the piston with fresh brake fluid and began assembly. Place the spring on the piston and insert into the bore:
Then secure with the set screw. Install the linkage with the new retaining ring/ clip and your ready to go.
And now for the rest of the story...
As any good searcher on NICO knows, you should replace the rubber line with a stainless steel line. So I bought the SPL line:
Things were going great. I'll be bleeding in NO time. So I removed the dampener loop:
Then went to work on the slave cylinder (which I thought was fine.. 
) The bleeder broke off!!!
SON OF A ...!!!
Called Autozone... nada.
Called Nissan... nada.
Called O'Reillys.... Jackpot!!! $15.00 with a lifetime warranty!
I wanted to keep the OEM unit, but I also wanted to be able to drive for the next 4 days.
Got the slave cylinder, finished removing the dampener loop, bent the hardline around very carefully, and done!
Then I had my daughter help me bleed the system, which took no time at all.
So that's it. I was going to take pics of the finished installation, but it's been done before. SEARCH...
I hope this hasn't been written up before, if it has, I didn't see it when I searched.
All in all, not a difficult job. My advice to anyone taking on this task is to have ALL the parts you could possibly need available so you don't have to scramble around at the last minute.
Let me know what you think...
thanks!
