Hello everyone,

Instead of the usual first post being a cry for help, I thought I would contribute something I learned that might help others. This site has been a great resource to learn about my new 350z so I wanted to give back.

Recently I had my clutch replaced and when I got it back the peddle returned significantly slower than I wanted it to. My foot would often come off the peddle if I tried to shift quickly. Cold weather (~10°F) seemed to exaggerate it. I would also get periodic "pings" when I pressed the peddle down. Strange, but the shop assured me everything was fine, though we all know how that goes...

I should note I have a 2004 350z roadster so my slave cylinder is external to the bell housing. Here is what I did to fix it.

Knowing the shop probably used some old DOT3 fluid that probably absorbed lots of moisture, I figured I would flush the clutch again to make sure they didn't leave any air in the line and to rule out the moisture freezing in the line making it difficult for the fluid to travel. I also decided to use a DOT 5.1 fluid for two reasons. It has a much lower viscosity than DOT 3 which would reduce the effect of restrictions and drag on the fluid, and it has a much higher wet and dry boiling point. The latter shouldn't be a problem even in he summer as the clutch line should never get that hot, but it doesn't hurt.

Note: Do NOT use DOT 5 fluid. It is silicon based and hydrophobic meaning it doesn't absorb moisture. The slightest amount of moisture in the line will cause drastic compressability issues caused by water phase changes that no one here probably wants me to go into detail about . Also the seals and system in the clutch hydraulics are designed for glycol based fluids, so it's best to stick with them.

Bleeding the line went well. I read a lot of posts about people having trouble bleeding their clutches so here are some tips I learned.
1. Make sure your clutch return position is properly set. The master has to be able to extend all the way back to receive more fluid from the reservoir. Also it can keep your clutch from fully engaging causing premature wear if you don't.
2. Have a second person pumping the clutch for you. Have them hold the peddle down while you loosen the bleeder just enough to let the old fluid drain slightly. Be sure to use a bleeding tube to prevent fluid getting everywhere and air getting sucked back up into the slave.
3.After they depress the peddle and you release the fluid, tighten the bleeder valve back up. They will now need to pull the peddle back up manually. You should see the slave piston retreat away from its contact point so there is a slight gap. Have them leave the peddle up for about 5 seconds to let new fluid enter the master cylinder and have them pump the clutch a few times until it returns back normally for them again.
6. Repeat the press hold, drain, close valve, pump sequence over and over.
7. Not much fluid is pumped out per run, you will have to do this a lot. I ran through about a 1/4th a qt of fluid just to be sure it got flushed.

I found lots of air and obviously old fluid in my line. The shop just didn't do their job and was too lazy to bleed the lines despite taking the system apart and exposing it to air.

After this all my clutch troubles were fixed. No more pinging sound, which was probably all the air. No more cold weather freezups. The fresh fluid without the absorbed moisture probably helped this. While I used DOT5.1 a DOT3 probably would have worked just fine but I still feel the lower viscosity gave me better response and feel of the clutch engagment point without as much of a fluid restriction dampening the clutch movement.

So my recommendation is to be sure to flush the line and just from personal experience DOT 5.1 works well for me.

Hope this helps someone else and thanks for being a great community!