DIY - Swap clutch slave cylinder and hydraulic line for improved feel and control

[Stonehenge]

Just wanted to say thanks to @Ultramaroon for this recommendation & user guide.
I have a 2016 BRZ RHD (being in the UK) owned for 6 months. The clutch developed the infamous screech from the fork pivot in December, so it made sense to try this mod at the same time as addressing the screech. Adjusting the bite point is pretty simple (following this guide), at least once you are upside down in the footwell! Rotating the push rod (rather than removing the bracket) allowed me to judge the pedal movement against the sensor switch which I found helpful. The new slave cylinder was only £36 from Euro Car Parts (for anyone in the UK) and is still Made in Japan. As suggested in the guide, I adjusted the bite point as low as possible, then swapped the slave cylinder, then re-adjusted the bite point down slightly once more.
I left the original assist spring in place and the clutch action is much better and still acceptably light. The pedal stroke remained within the recommended tolerance too, happy days. Driven 1,200 miles in the six weeks since making the swap and all’s well so far.

[Ultramaroon]

Originally Posted by Stonehenge

Driven 1,200 miles in the six weeks since making the swap and all’s well so far.

Welcome to the forum. I'm happy to hear that you're enjoying the change. One of these days I'll replace the perch I lost, and reinstall my assist spring. I still regret removing it.

[Stonehenge]

Originally Posted by Ultramaroon

Welcome to the forum. I'm happy to hear that you're enjoying the change. One of these days I'll replace the perch I lost, and reinstall my assist spring. I still regret removing it.

Thanks! Glad I decided to leave the spring in place :-) It looked a nightmare to replace on RHD cars, which put me off trying it.

[Ohio Enthusiast]

To each his own. I much prefer the clutch without the assist spring (I swapped the larger slave cylinder and have adjusted the pedal already).

[Ultramaroon]

The assist spring should be called the over-center, or cam spring because it does more than lighten the pedal. It is also a pedal return spring. Near the top of travel, it flips to hold the pedal up. Assuming that the turnbuckle for the bellcrank is adjusted properly, this keeps all engine and chassis vibration from being transmitted directly into the master cylinder when it isn't actually in use. Other designs have a dedicated return spring just for this purpose.