Clutch Problem
 

Clutch Pedal was feeling spongy, then wouldnt return all the way, now it just snaps down to the floor and does nothing.. Noticed fluid leaking from under car, ordered new slave cylinder, Mechanic friend installed new, says system still wont hold pressure. He says that the slave was leaking, but thinks the Master needs to be replaced too. Whaddya guys think. I heard that the slaves have about 1/3rd the life of the master cylinders.
Any test we can do to make sure the we've done it right before I order more parts??

Sergio

my pedal went to the floor one day, my slave was leaking, but my master cylinder was also leaking a little, replaced both and all is well.

Is there any trick to bleeding the system???

Yea I'm going to do my master and slave once I fix my engine problems that happened today. You are suppose to replace both cylinders. Cause it saves time and it's only like 50$ more.

The slave cylinder is hard to bleed. I just did mine. You have to jack the back of the car up in the air... high as possible. This helps get the bleed port on the slave cylinder higher... it also lets you get under there. I tried a MightyVac kit to bleed... it was a waste of time. A pressure bleeder is the way to go. I had two friends help. One pumped the pedal and the other poured in the brake fluid. You don't have much fluid in the tank and you don't have to accidentally suck in more air. Be patient and careful.

Like everyone else said, replace both, the other will be going soon. If you have a/c, the back mounting nut on the master cyl is hard to get at, so have a good socket set with extentions and swivels too. The slave is simple, even with having to remove the starter. Bleeding @#$%^&* sucked manually. Took about a day, many breaks with the pedal up so the fluid could seep, I was about to give up when it finally started pumping. Any kind of system to help has got to be better than going at it with a friend pumping the pedal.

How hard is it to replace the master cylinder for the clutch on a 951???

It's really not that hard to replace the clutch master cylinder. You have to undo a bunch of vacume hoses next to the brake master cylinder and reservoir (both brakes and clutch use the same reservoir) to get at it. Like i said before, the back mounting nut is hard to get at if you have big hands, so have a good socket set with various swivels and extentions. Also would be good to have a flare wrench set for removing the hydraulic line from the master cylinder to avoid stripping it. Off the top of my head, here's how to do it.

Undo the hoses next to the brake reservoir to gain access to the master cylinder below that. Use a small set of vise grips to close off the hose going from the reservoir to the master cylinder.

Inside the car, undo the clip holding the master cylinder to the clutch pedal. ( I needed a socket snake to get at some of the back mounting nuts for the cover that has to be removed).

Back under the hood, using a flare wrench, undo the hydraulic line coming out of the front of the master cylinder. Then remove both mounting nuts holding the master cylinder on the firewall. That back one was hard to get at for my car with A/C. Remove the hydraulic line in (that you clamped off earlier). You should then be able to remove the master cylinder. It was much harder to get out than to put the new one back in, but installation is just the reverse, be careful to replace the vacume hoses properly.

Then bleed the system, if I do that again, I think I'll buy some sort of bleeder. Manually it seemed like it would never work, but it eventually started pumping.... the next day late.

There's a previous post on this, several probably, I had this pic stored showing the hoses and area you'll be working in.

sergio
I also had to battle the problem of bleeding the clutch slave
cylinder. First on my 944S and just recently on my 951.
Someone had written a reply to aprevious post, and suggested
using an oil can with the pump handle. Fill the can with brake fluid
and use a short piece of tubing attached to the bleed nipple on
the slave cylinder. Pump the fluid in from the bottom. It works
great. Thanks to whomever posted this previously, it saved me
a lot of time. Another tip, you can rebuild these slave cylinders
with a rebuild kit made by Wagner for about $17. I rebuilt the old
cylinder from my 944S
Ralph