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

[H1C]

Originally Posted by Ultramaroon

The stock setup of the clutch is frustratingly vague because there is too much leverage between the clutch pedal and the pressure plate. I started looking for ways to change the diameter ratio between clutch and master cylinders when I stumbled into the no-brainer solution. The stock slave cylinder has a 13/16" bore. Subaru has another clutch slave cylinder with a slightly narrower bore of 3/4". It is otherwise identical to stock but decreases the leverage by 17%. Here is the original thread leading up to this DIY. Enjoy.....

I've been meaning to thank you for this thread for the longest time. I did this mod back in the spring, after putting on a catless header, and it greatly improved clutch feel -- being able to tell where the bite point is.

For some reason, after installing the header and tune, I was slipping the clutch a lot more than previously from stop lights. Maybe it was the filled-in torque curve, but I was having the hardest time being able to feel where the clutch was biting. I've been driving manual for 30 years, and when the car was stock I thought the clutch was on the light side but ok in feel. After the header and tune I was slipping the clutch a lot more than I intended to. This mod really restored the drivability of the clutch. Thanks a lot for sharing it with us!

[Ultramaroon]

Originally Posted by H1C

I've been meaning to thank you for this thread for the longest time. I did this mod back in the spring, after putting on a catless header, and it greatly improved clutch feel -- being able to tell where the bite point is.

For some reason, after installing the header and tune, I was slipping the clutch a lot more than previously from stop lights. Maybe it was the filled-in torque curve, but I was having the hardest time being able to feel where the clutch was biting. I've been driving manual for 30 years, and when the car was stock I thought the clutch was on the light side but ok in feel. After the header and tune I was slipping the clutch a lot more than I intended to. This mod really restored the drivability of the clutch. Thanks a lot for sharing it with us!

Thank you for the feedback! Never gets old hearing from folks who like it.

[H1C]

Originally Posted by Ultramaroon

Thank you for the feedback! Never gets old hearing from folks who like it.

My pleasure -- thank you for all your technical knowledge and level-headedness. I've learned a ton from your posts!

[jcw99]

Originally Posted by H1C

My pleasure -- thank you for all your technical knowledge and level-headedness. I've learned a ton from your posts!

Ditto

[chickunfut]

Just finished the swap today. Best mod for this car without a question. Makes a huge difference in the drivability of the car. Worth every penny. Thanks for the info !!

[PA-86]

Finally gave this slave cylinder swap a try after owning the car for several years (prompted by driving my gf's Cooper GP which has a stiffer clutch pedal). Thanks very much for the suggestion and walk-through, this is one of my favorite mods for sure! Initial impressions are; much more predictable engagement point, shorter overall pedal travel, and slightly stiffer pedal feel. The swap took about a half hour and that's only because I decided to completely change out the old brake fluid. Parts were sourced from subaruonlineparts.com

[Ultramaroon]

Originally Posted by PA-86

Finally gave this slave cylinder swap a try after owning the car for several years (prompted by driving my gf's Cooper GP which has a stiffer clutch pedal). Thanks very much for the suggestion and walk-through, this is one of my favorite mods for sure! Initial impressions are; much more predictable engagement point, shorter overall pedal travel, and slightly stiffer pedal feel. The swap took about a half hour and that's only because I decided to completely change out the old brake fluid. Parts were sourced from subaruonlineparts.com

My pleasure! Thanks for your feedback.

With over 40 Kmiles of daily stop-&-go commuting, my clutch cylinders continue to work flawlessly.

[PA-86]

I'm almost at 50k miles, just recently cooked a coil pack. Only clutch related issue I've been experiencing is a squeaky/stiff feel in the clutch pedal when I get to the last inch or so of travel. Not at all related to the slave install, by the way.

[Ultramaroon]

Originally Posted by PA-86

I'm almost at 50k miles, just recently cooked a coil pack. Only clutch related issue I've been experiencing is a squeaky/stiff feel in the clutch pedal when I get to the last inch or so of travel. Not at all related to the slave install, by the way.

Yeah. I've had the same. Squeaky is the dry fork. Stiff is the TOB slowly gouging out the quill. Shitty design.

[HSUBLU]

I still need to do this at some point...

[Ultramaroon]

Originally Posted by HSUBLU

I still need to do this at some point...

[N234]

Has anybody put a speed bleeder on this? Is it the same size as the original slave's bleed screw?

Sent from my SM-G930W8 using Tapatalk

[funwheeldrive]

Originally Posted by HSUBLU

I still need to do this at some point...

Me too. I'm nervous that I'm going to mess something up. I'm pretty comfortable with doing regular maintenance, but I've never messed with master cylinders or stuff like that.

[Ultramaroon]

Originally Posted by funwheeldrive

Me too. I'm nervous that I'm going to mess something up. I'm pretty comfortable with doing regular maintenance, but I've never messed with master cylinders or stuff like that.

It's just plumbing. If you can fix a faucet, this'll be a cakewalk. Cleanliness is the key factor.