If bleeding the clutch fixes it then I would imagine that there has to be air getting in to the system. Or you are moving around an existing air bubble, which moves ones you start driving. Did you follow the steps in this thread for bleeding?

https://www.dsmtuners.com/threads/how-to-properly-bleed-your-hydraulic-clutch.213503/

Also did you bench bleed the master cylinder before installing it? Sometimes that can get air trapped in there that is hard to get out with bleeding alone. Check all fittings as well and make sure they are tight.

Is the shifting notchy when the clutch is working? Does the pedal engagement point move around at all before it just disappears? Does the clutch fluid come out clean when you have to stop to bleed the system?

I followed those exact steps in bleeding except when I'm stranded .
No I did not bench bleed the master. I didn't know that was a thing until digging into the forums later
Clutch release point feels normal until I come to a random stop and then i can't get into gear but pedal still pretty stiff.
This problem didn't appear until I replaced the old hardline with a used braided line. I was thinking about using Teflon tape on the braided line connection to the master. I've checked for tightness on all connections from master to slave.

If it started with the install of the braided line, that's probably the culprit. It may start to expand when it gets hot.

I'm using the factory hard line with just a braided line at the end to replace the stock rubber line. I am running a LUK master and slave cylinder and they work fine with my ACT 2600.

talonlan3 said:

I followed those exact steps in bleeding except when I'm stranded .
No I did not bench bleed the master. I didn't know that was a thing until digging into the forums later
Clutch release point feels normal until I come to a random stop and then i can't get into gear but pedal still pretty stiff.
This problem didn't appear until I replaced the old hardline with a used braided line. I was thinking about using Teflon tape on the braided line connection to the master. I've checked for tightness on all connections from master to slave.

Click to expand...

Are you trying to put it only in to first gear when you come to a stop or does it not go in to any gear?

Teflon tape will not do anything here. If you have the braided line going all the way to the master cylinder from the slave do you have a link or something to the fittings and line that you used? It is possible that it could be the wrong flare I suppose.

Sometimes things are just a coincidence I have learned and were going to brake regardless.. Or the changes agitate an already existing problem. So don't rule out that it might be something mechanical and not hydraulic. There is always the option if installing the previous lines if they are not damaged and seeing if the problem persists.

Previous lines are in the landfill .
It won't go into any gear when it happens.
I think i goes master cyl.---NPT to AN adapter---braided line---slave. I don't believe I used any teflon on the NPT thread. I will look it over when I get back home tonight.

I believe NPT fittings are the wrong type. The master fitting should be an M10x1.25 inverted-flare fitting similar to the fittings for the brake lines. You can find the correct fitting here https://www.anplumbing.com/.

I've had similar bad experience with a braided clutch line when converting Civic automatic transmission to a stick shift....the factory hard lines are best....

Mello said:

I believe NPT fittings are the wrong type. The master fitting should be an M10x1.25 inverted-flare fitting similar to the fittings for the brake lines. You can find the correct fitting here https://www.anplumbing.com/.

Click to expand...

I'm not sure if it's NPT I just assumed being a hydrolic line. But I will make sure tonight.