Marv

I just noticed that my clutch pedal is not engaging correctly. It seems to travel half way with little back pressure before it starts feeling like it is doing something.

This afternoon it would not return all the way after depressing. I had to pil it back with my toe. Pumped a half dozen or so times and it seemed almost normal.

Fluid level is correct. It was replaced and bled about 15K miles ago. What is the likely culprit—master or slave cylinder? How do I test?

De Jeeper

If i had to guess its the master. The fluid can bypass the plunger via a bad seal. When the slave goes it usually leaks. Check underneath for fluid....also check the firewall on both sides where the clutch rod goes through for fluid too.

I swapped in a 997 gt mc, its a couple mm larger bore and it creates a firmer pedal.

Many posts in the upgrade if u search, an adaptor may be need on one of the lines.

weberlukas74

Based on your description, it could be either the master or slave cylinder causing the issue. Here's a quick test to help figure it out: when the engine is off, give the clutch pedal a few pumps and see if it gets firmer. If it does, it might be the slave cylinder; if it stays mushy, the master cylinder could be the issue.

Also, keep an eye on the fluid level and check for any leaks around the master and slave cylinders. It's a good idea to bleed the clutch system again, even if the fluid level seems okay. Sometimes, air pockets can mess with the pedal feel. Make sure to use a good-quality brake fluid and follow the right bleeding procedure.

Lastly, check the flexible hose connecting the master and slave cylinders. If it's damaged or collapsed, it could be messing with the fluid flow and causing the symptoms you mentioned.

Marv

Well, pumping it about 20-30 times with engine off does indeed make the pedal firmer, but that is more than a "few" times.

993GT

check for a small leak, if no leaks then most likely a master or bleeding wasn't fully done and an air bubble has worked its way in. Slave generally only fails with a leak- is simple hydraulic cylinder

Marv

Bleeding the slave cylinder did not help. I can’t see any fluid leaks, but if it was leaking I would expect it to be inside the clutch housing. Also, the fluid reservoir level looks normal.

Again, you pump the pedal a few dozen times and seems to work normally, but when the car sits for a few hours the pedal goes down, and will not return without pulling it back up with my toe.

993GT

what method are you using to bleed? sounds like an air bubble in the master or the master is defective internally

Denny Swift

Based on your description, it sounds like the master to me. Try pressing the pedal very slowly, so it takes maybe 10 seconds to fully depress it, but maintaining constant low pressure on it. If the seals in the master are worn, slow, constant pressure will allow the clutch to be fully depressed, without the clutch actually engaging. The fluid will just ooze past worn seal rather than being forced through the line if you apply light contact pressure.

996FLT6

Clutch spring ? Blew mine when I mis-shifted from 5th to 2nd .. pp plate etc popped but after replacement notice my clutch was abit lazy on engagement. It is a spring I kinda remember 3 springs on one part. Gets tried and stretched. Just my 2 cents.

Marv

Good thought, but pumping the pedal brings it back to normal.

I ordered both slave and master cylinder. Might as well since the car now has 155K on the first set.

XavierLaFlamme

That is the path I would take. I did that on my 993.

993GT

it's not the slave if it's not leaking...if no leaks its the master or bad bleeding

Marv

Bleeding the system did not work. No visible leaking at either end, but I did not pull the slave out. So, I can't rule that out, but I'll start with the master first and see what happens.