Bleeding clutch slave cylinder

[Mark944na86]

I've been looking at the brake fluid in my clutch fluid reservoir (separate reservoir on RHD cars), and it's looking like it needs a change. Actually, it's looking pretty nasty. So, what's the recommended procedure for changing fluid? Bleed from slave cylinder only, or from master cylinder first?

Also, are there any pictures of where the slave cylinder actually is ('89 S2)? I've read in Clark's Garage that removing the starter motor makes access easier, but I haven't seen any pictures of where the slave cylinder is situated. Is it simply a case of it all being obvious once the starter motor is out and you're under the car?

Any tips or hints on the procedure appreciated.

-Mark

[SoCal Driver]

Once the starter is out it's quite obvious.
One of the "tricks" I use when replacing the slave is to connect the hose firmly with the slave hanging straight down and the bleeder up. Open the bleeder (attached via tubing to a catch reservoir) and slowly pump the clutch refreshing the brake fluid as necessary. Close the bleeder and rotate the slave on the hose connection.

Note the connection has to be kept tight enough not to allow air in but allow the slave to turn about 90 degrees. Bolt the slave into place and tighten the hose connection. No bleeding required after bolting the slave in.

[sayporsha]

The clutch hydraulics should be bled at the slave. You can do it without removing the starter, but you'll be hatin' life. IMHO it's better to remove the starter first. I also immobilize the clutch fork by inserting a large socket into the access hole in the bellhousing. That way the fluid pressure is spent on flushing the slave, not actuating the fork.

I just did this on my 86 951, and learned a valuable lesson: don't over-bleed it. It's a short distance from the master to the slave. About 6-8 pumps clears the entire system.

It's easy to pump the reservoir dry because there's a baffle that prevents fluid from flowing to the feed tube from the rest of the reservoir. Top it off, pump about 4 times, top it off again & pump another 4 times. That just about does it. For me, this de-bunks the myth that 944 clutches are hard to bleed. It's more like they're too easy to bleed!

However, if the fluid looks nasty in the reservoir, it's even nastier the slave & brake calipers where the environment is much more harsh. You should bleed both systems. I use ATE Super Blue because I track the car & it has a high boiling point. If I wasn't tracking the car I'd probably use Castrol.

Best of luck,