Clutch slave bleeding tips

[Alan28]

I’ve been trying to find info on bleeding the clutch slave cylinder (since I was going to bleed my brakes) and the only information I could find was about accessing the bleed valve from below the car. This requires doing it “blind” or by feel since you cannot see the bleed valve directly from below the car.

Turns out you can easily see and reach it from above. I climbed into my trunk (fair warning, In only 140lbs) and leaned across the engine bay. Photos attached show the bleed valve circled in red. Additional photos included just to orient you to its location (in front of and on the left side of the engine).

Pro tip, get some smaller gauge tubing to attach to it before you bleed it. I used the tubing from my normal brake caliper bleeder bottle and it was large enough that it did not stay firmly attached to the nipple (and I spent a good bit of time cleaning up brake fluid that dripped down the side of my engine).

Not sure if others had trouble opening the bleed valves on their brake calipers, but mine were torqued down crazy tight (I ended up loosening them with a 11 mm socket first before attaching my bleed tubing/bottle). Also, I have two different sets of flare wrenches and on both, the thickness of the heads made getting them onto the bleed valves difficult. I had to put them on the nipple, loosen 1/16th of a turn, flip the flare wrench over, loosen it another 1/16th of a turn, flip it over, etc.

If anyone knows of better flare wrenches for AP calipers, I’m all ears

 

[Blackthought_]

How did this work out for you, did you bleed the clutch first before the brakes?

I’ve been reading up on this and it looks like in earlier Evoras you needed to access the nipple from underneath and was a complete pain. Seems like this is as easy as reaching into the engine compartment? Considering doing this with a motiv power bleeder.

 

[VL3X]

Assuming it's the same as the Evora GT.. The brakes and clutch share a reservoir, so you hook up the power bleeder up front and climb in the trunk to reach the clutch bleeder first.. Then do the calipers. It's a pain getting back there and have to do it mostly blind, but it's not too bad.

 

[F1 SML8R]

It's identical to the first gen Evora from 15 years ago. One reservoir for both the clutch and brakes. Also, what makes this critical to be done at least once a year (I did it every 6 months), is the slave cylinder's proximity to the exhaust manifold. The operating environment couldn't get any tougher for the fluid (essentially cooked daily). This is also what caused so many master cylinder failures combined with the fact that they were made of plastic (what were they thinking...).

 

[Alan28]

How did this work out for you, did you bleed the clutch first before the brakes?

I’ve been reading up on this and it looks like in earlier Evoras you needed to access the nipple from underneath and was a complete pain. Seems like this is as easy as reaching into the engine compartment? Considering doing this with a motiv power bleeder.

Worked out great. Definitely easier reaching the clutch slave bleed nipple from above rather than from below

 

[VL3X]

It's identical to the first gen Evora from 15 years ago. One reservoir for both the clutch and brakes. Also, what makes this critical to be done at least once a year (I did it every 6 months), is the slave cylinder's proximity to the exhaust manifold. The operating environment couldn't get any tougher for the fluid (essentially cooked daily). This is also what caused so many master cylinder failures combined with the fact that they were made of plastic (what were they thinking...).

Yep, the later gen 400s and GTs came with heat wrap around those lines to help prevent the master cylinder failure issue.

 

[Rapture]

It's identical to the first gen Evora from 15 years ago. One reservoir for both the clutch and brakes. Also, what makes this critical to be done at least once a year (I did it every 6 months), is the slave cylinder's proximity to the exhaust manifold. The operating environment couldn't get any tougher for the fluid (essentially cooked daily). This is also what caused so many master cylinder failures combined with the fact that they were made of plastic (what were they thinking...).

Wait, are you suggesting we should be replacing/bleeding the brake fluid every 6 months to a year?

 

[F1 SML8R]

I'm not suggesting anything, simply stating what I did after understanding the operating environment of the slave cylinder and my specific use case. I'm one of the weirdos that actually drives his car, like a lot (12-15k miles a year).

 

[Blackthought_]

It's identical to the first gen Evora from 15 years ago. One reservoir for both the clutch and brakes. Also, what makes this critical to be done at least once a year (I did it every 6 months), is the slave cylinder's proximity to the exhaust manifold. The operating environment couldn't get any tougher for the fluid (essentially cooked daily). This is also what caused so many master cylinder failures combined with the fact that they were made of plastic (what were they thinking...).

Gotcha. Did you access the clutch nipple from above like other members? Btw do you have flared wrenches did you’d recommend?

 

[Blackthought_]

Worked out great. Definitely easier reaching the clutch slave bleed nipple from above rather than from below

Did you do tires first then clutch? So it would be RR, LR, RF, LF then clutch?

 

[silent cilantro]

clutch first is what I've read

 

[RyanGphoto]

Do you guys mind elaborating on this. I drive mine 12k+ a year as well.

But have no idea what this is all about. Sorry just never heard of this.

What did this do? Why do it?

How do you bleed it?

Thanks
Ryan G

 

[VL3X]

Do you guys mind elaborating on this. I drive mine 12k+ a year as well.

But have no idea what this is all about. Sorry just never heard of this.

What did this do? Why do it?

How do you bleed it?

Thanks
Ryan G

Brake/clutch fluid is hygroscopic, meaning it absorbs moisture from the air, which can lead to issues like reduced boiling point and corrosion. High temp "race" fluid, which Lotus uses from the factory (like RBF600) has a higher boiling point but needs to be changed more frequently. The recommended service interval is every 2 years but should be done more frequently if tracking your car and intensely heating up the brakes frequently.

Honestly, if you're just daily driving with some spirited drives here and there, you're fine to go 2 years.

 

[RyanGphoto]

Brake/clutch fluid is hygroscopic, meaning it absorbs moisture from the air, which can lead to issues like reduced boiling point and corrosion. High temp "race" fluid, which Lotus uses from the factory (like RBF600) has a higher boiling point but needs to be changed more frequently. The recommended service interval is every 2 years but should be done more frequently if tracking your car and intensely heating up the brakes frequently.

Honestly, if you're just daily driving with some spirited drives here and there, you're fine to go 2 years.

Yep just daily driving (not every day either).

I'm guessing I should probably have this done by someone at this point, unless it's super easy ti do solo.

 

[VL3X]

I wouldn't say it's super easy, but doable with an hour or two and the right tools. Just be careful not to spill any brake fluid on painted surface (including the calipers).

 

[RyanGphoto]

I wouldn't say it's super easy, but doable with an hour or two and the right tools. Just be careful not to spill any brake fluid on painted surface (including the calipers).

I Def don't have the tools so I'll be taking it somewhere.

Is this part of any service at are supposed to get out just something that is common knowledge OR is it really only done by knowledgeable people?

 

[F1 SML8R]

There's a defined service interval for this. However, dealers have been known to skip the clutch slave bleed given it's buried and hard to get to. Instead, they'll only bleed the 4 calipers. How can this happen? Remember, the hydraulic fluid for both the brakes and clutch come from one singular master cylinder and reservoir. So, when someone comes in and asks for the fluid to be flushed/replaced, they technically have largely done it by only bleeding the 4 calipers. I specifically always call out the clutch slave and ask the tech on how they get to it. That usually confirms if they actually did it given it requires them to be a bit of a contortionist to get to it (from above or below).

 

[Blackthought_]

I Def don't have the tools so I'll be taking it somewhere.

Is this part of any service at are supposed to get out just something that is common knowledge OR is it really only done by knowledgeable people?

Generally you should do a brake fluid flush every 2 years or so but most folks are doing it earlier if you track the car

 

[allenyao09]

I'm about to bleed my brake fluid before I head to the track this weekend. Good to know that I have to bleed the clutch slave as well.