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

[Ultramaroon]

Originally Posted by Eldari

Just ordered the slave cylinder at Napa, they said they will have it by 9am tomorrow. They couldn't seem to locate the washers using the subaru number or find anything equivalent. Any suggestions? Is it just a generic washer?

I farted around on the napa website and found a Balkamp number hpp177101erl

Dorman part number 484-186 can be obtained through Oreilly and Autozone.

Originally Posted by Eldari

Is there any reason to swap the clutch line other than aesthetics? I could hold off a few days while I wait for a steel braided clutch line from amazon I guess if it's just for looks. Otherwise I could have the cylinder installed tomorrow night if I pick it up after work...

I've gone back and forth on this topic so, for the record, I'm going to dig in my heels. I see no functional benefit to using steel braided line on clutch hydraulics. Brakes, sure. Here's why.

Brake systems in comparison to clutch systems transfer very little hydraulic fluid between the master and slave (brake calipers). With brakes the primary function is a transfer of force, not motion. OEM nylon-braided lines strike a good balance between cost and effectiveness but still contribute quite a bit to sponginess in the brake pedal. Also, one brake master feeds 4 calipers with a hose at each one so the elastic effect is multiplied.

The clutch system operates at a fraction of the pressure felt by the brakes and the primary function is not force but rather, the transfer of motion. Also, there is only one short hose between only two cylinders. Nylon-braided hose is just fine. If you want to prove it to yourself, grab ahold one of the wheel hoses while a friend stomps on the brake. You can feel the hose expand. Do the same with the clutch line. Nothing.

If you want to add the steel braided line for the bling factor, fine. Just don't expect to feel any difference in your left foot. It ain't there.

[Eldari]

Originally Posted by Ultramaroon

I farted around on the napa website and found a Balkamp number hpp177101erl

Dorman part number 484-186 can be obtained through Oreilly and Autozone.

I've gone back and forth on this topic so, for the record, I'm going to dig in my heels. I see no functional benefit to using steel braided line on clutch hydraulics. Brakes, sure. Here's why.

Brake systems in comparison to clutch systems transfer very little hydraulic fluid between the master and slave (brake calipers). With brakes the primary function is a transfer of force, not motion. OEM nylon-braided lines strike a good balance between cost and effectiveness but still contribute quite a bit to sponginess in the brake pedal. Also, one brake master feeds 4 calipers with a hose at each one so the elastic effect is multiplied.

The clutch system operates at a fraction of the pressure felt by the brakes and the primary function is not force but rather, the transfer of motion. Also, there is only one short hose between only two cylinders. Nylon-braided hose is just fine. If you want to prove it to yourself, grab ahold one of the wheel hoses while a friend stomps on the brake. You can feel the hose expand. Do the same with the clutch line. Nothing.

If you want to add the steel braided line for the bling factor, fine. Just don't expect to feel any difference in your left foot. It ain't there.

@Ultramaroon Thanks, that's what I figured and for now I just want the vagueness gone so I am going to start tonight and not bother with the clutch line. For a first timer would you recommend buying the bleeder kit? I've never bled anything before and could get a friend to help if needed, but the kit sounds like something that might make this a no-fuss job?

[Ultramaroon]

Originally Posted by Eldari

@Ultramaroon Thanks, that's what I figured and for now I just want the vagueness gone so I am going to start tonight and not bother with the clutch line. For a first timer would you recommend buying the bleeder kit? I've never bled anything before and could get a friend to help if needed, but the kit sounds like something that might make this a no-fuss job?

I've never had luck with bleeder kits but maybe it's because I haven't found a decent one. Maybe someone else can chime in with some advice. I haven't even bothered with an assistant with the last couple I've done. It can be bled just by pushing back on the clutch fork.

Also, be sure to dab a little grease on both ends of the plunger (pin?) on the new slave. I still need to add that step to the process.

[Eldari]

Originally Posted by Ultramaroon

I've never had luck with bleeder kits but maybe it's because I haven't found a decent one. Maybe someone else can chime in with some advice. I haven't even bothered with an assistant with the last couple I've done. It can be bled just by pushing back on the clutch fork.

Also, be sure to dab a little grease on both ends of the plunger (pin?) on the new slave. I still need to add that step to the process.

Is there a specific type of grease to use? I have some WD-40 White Lithium Spray grease, but I'm not sure what grease I should use. Also, the Napa guy talked me out of buying the torque wrench saying it wasn't needed? His exact words were "Just give it a decent crank and you should be fine..."

Having never used, or owned a torque wrench.. should I go pick one up at harbor freight or something?

I have the cylinder sitting here beside me and a quart of the fluid, I just want to have all my ducks in a row before I start and not be able to finish lol.

[FyeaFRS]

Originally Posted by Eldari

Having never used, or owned a torque wrench..

You've been living life all wrong... :P

[Eldari]

Originally Posted by FyeaFRS

You've been living life all wrong... :P

I work on computers all day, never had need of it before now. I'm just trying to learn now because I really enjoy the car and want to figure this stuff out.

[Ultramaroon]

Originally Posted by Eldari

Is there a specific type of grease to use? I have some WD-40 White Lithium Spray grease, but I'm not sure what grease I should use. Also, the Napa guy talked me out of buying the torque wrench saying it wasn't needed? His exact words were "Just give it a decent crank and you should be fine..."

Having never used, or owned a torque wrench.. should I go pick one up at harbor freight or something?

I have the cylinder sitting here beside me and a quart of the fluid, I just want to have all my ducks in a row before I start and not be able to finish lol.

Mr. NAPA is full of shit. Just a few posts back, someone twisted off their banjo bolt. This recent thread turned out to be a good primer on torque wrenches. I recommend getting an "old school" one like I mentioned there. Brand doesn't really matter because they're simple. Still, don't cheap out.

For the bleed nipple. Think of it like a water spigot. Take it apart to inspect it before you install it. You can see it's pretty delicate. No need to crank down on it.

Here's where I specify the grease. I bought a tube of Valvoline Max Life #2 Red Grease for this application.

[Eldari]

Originally Posted by Ultramaroon

Mr. NAPA is full of shit. Just a few posts back, someone twisted off their banjo bolt. This recent thread turned out to be a good primer on torque wrenches. I recommend getting an "old school" one like I mentioned there. Brand doesn't really matter because they're simple. Still, don't cheap out.

For the bleed nipple. Think of it like a water spigot. Take it apart to inspect it before you install it. You can see it's pretty delicate. No need to crank down on it.

Here's where I specify the grease. I bought a tube of Valvoline Max Life #2 Red Grease for this application.

Thank you for being so detailed in your posts, truly helps for beginners like me.

Edit: Will make sure I come back and Thank your threads once I get 10 posts lol

[Ultramaroon]

Originally Posted by Eldari

Thank you for being so detailed in your posts, truly helps for beginners like me.

Edit: Will make sure I come back and Thank your threads once I get 10 posts lol

Bah! No worries. Best wishes. You'll love the results.

[Eldari]

Originally Posted by Ultramaroon

Bah! No worries. Best wishes. You'll love the results.

Just got back from Autozone and the only red#2 they had was in the below picture, will this work?


Also, Napa and Autozone both had a 14 day wait for the washers listed in the part number, but autozone did have this variety pack, which 2 are the correct ones? and Why are they copper instead of silver colored like the OEM picture on Subaru's page?

[Ultramaroon]

Originally Posted by Eldari

Just got back from Autozone and the only red#2 they had was in the below picture, will this work?


Also, Napa and Autozone both had a 14 day wait for the washers listed in the part number, but autozone did have this variety pack, which 2 are the correct ones? and Why are they copper instead of silver colored like the OEM picture on Subaru's page?

Good on both. Use the washers/gaskets closest to the size of the originals. I'm not sure what the fancy-schmancy Subaru material is but I'm betting it was chosen over copper to cut cost. Copper has forever been the de-facto standard for this application. I think I bought the same kit. No worries.

I have the same size tube. It's going to last forever. -___-

Now that you have that tube of grease, it's important to understand that different greases can be wildly incompatible. I have personally seen machines destroyed because of it. The thickening agent in grease is not the lubricant, rather it holds an oil in suspension. When incompatible greases are mixed, the suspension hardens and the oil separates leaving behind a worthless crusty mess.

Just food for thought in case you're tempted to stick that tube in a gun and use it for everything.

[Eldari]

Just wanted to post a followup and let anyone wondering whether they should do it to go for it. It was not difficult, took less than an hour of actual work time, and the pedal feels much better now. I may still swap to the MTEC spring, but I'm going to give it a few 100 miles first to make sure it's needed. Doing this swap is also a really good excuse to clean out the engine bay if you are like me and have never done so. Made it a part of my car wash routine from now on.

Also, Huge thanks to UltraMaroon for all the help he provided, the man knows his shit.

[xsl27x]

I grabbed the exact same stuff @Eldari got from Autozone, works great. Much better feel without the helper spring. I have an Mtec one in the mail, so I'll pop it in when it gets here and report back.

[Eldari]

Originally Posted by xsl27x

I grabbed the exact same stuff @Eldari got from Autozone, works great. Much better feel without the helper spring. I have an Mtec one in the mail, so I'll pop it in when it gets here and report back.

Let me know, super interested