I have spent a hour searching but have not seen any issues like mine so I thought I would post and see..

My car is a 05 sedan 6MT with 70K miles.. The clutch pedal is fine most of the time, but if stuck in traffic or shift allot my pedal gets weird..
Normally it has pressure as soon as I push the pedal down, but then it changes and I can push it 2 inches down before I feel pressure.. Today it went about half way down before I felt any pressure.. The car was hard to drive but I was able to get it home..

I checked the fluid and it is fine and full. No leaks... I am guessing the slave cyl. is going but would like to make sure.. Also, anyone know if the slave cyl can be replaced without pulling the transmission??

Thanks, sorry for such a long post...

 

It doesn't sound like your very mechanically inclined so ill try and word this best I can with simple instructions.

1) how long have you been driving manual transmissions?

2) do you have access to a lift or jack/jack stands to get underneath the car?

3) since you have 70k miles when was the last time you changed out your transmission fluid? if you haven't done that recently thats the first thing to do.

4) it sort of sounds like heat soak which would lead to the clutch line. but first things to do is change out your transmission fluid if it hasn't been done yet and change your clutch fluid if it hasn't been done yet either.

5) what aftermarket parts (upgrades) do you currently have?

 

I am mechanically inclined, just hard trying to explain a pressure change in the pedal, at first I thought I just could not drive a manual because the pedal would engage sooner then normal and I could just tell it was not right..

1. 22 years...
2. Yes, fluid was full but looked kinda dark
3. Bought it at 60K, so I never changed it, but can.
4. I will change the fluid, I was told the slave cyl. was in the transmission but I looked online and it looks like it is just on top of it.. Master is only $55 and slave is $60 so it has to be one of the 3..(fluid, slave or master)
5. HKS muffler, pulley, intake spacer, 19" coupe wheels

 

If you haven't personally changed out the transmission fluid then i would suggest doing so. Even flushing your clutch fluid out and adding new fluid would help. Also a lower than normal engagement point is also signs of a worn clutch.

You can't really wear down the slave cylinder that much other than having it leak. All it is, is a piston that pushes a rod thats sealed by a plastic caseing and a rubber boot with a metal piston. After 70k miles it shouldn't of gone out.

Although, if there is a clutch fluid leak somewhere then it can cause air to enter the system which you should know, and putting new fluid in your clutch system and bleeding it should help you troubleshoot further into what the issue could be. Like I tell people at my shop to use the 5S's, Start with the Small, Simple, Stupid Shit.

Yeah when i ran into my pivotball snapping issue I replaced the clutch master and slave cylinder with brand new ones and my G had about 65k at the time and the clutch slave cylinder didn't look bad at all nor did the master cylinder. I have heard of both of those going out on some cars before though so replaceing them at 60k+ miles isn't a bad idea.

I would have to suggest that whenever you or someone else changes out their clutch whether it's at 70k miles or more then it would be smart to change out the following:

-clutch slave cylinder (OEM)
-clutch master cylinder (OEM)
-clutch fluid line with stainless steel so there is hardly to no heat soak through the line into the system. (Aftermarket)
-throwout bearing (OEM)
-pilot bearing (Nismo)
-pivotball for stainless steel due to issue with them snapping under heavy load and use.
-clutch pressure plate due to wear during use

if you get a new clutch then ensure it is installed correctly (aligned) and you replace the pressure plate with it as well if there is any signs of wear and insure you torque the pressure plate to flywheels bolts down to 29ft-lbs. Then torque the transmission to engine bolts in the correct order with the correct torque.