Stainless Steel Clutch Line DIY

For the 6MT drivers out there. I've done this a few times now. Thought I would document it in case anyone else is interested.

Why?

A stainless steel clutch line expands less under heat, supposedly providing more consistent pedal feel in a range of driving scenarios from daily to spirited to track. Also, a long enough aftermarket line has the potential to delete the clutch accumulator "swirl valve" that is attached to the master cylinder. Yes, this is a second delay valve in the clutch hydraulic system on our cars (the first one being the popular bleeder block restrictor removal). Lastly, if you look at aftermarket lines compared to OEM, the OEM has a thin metal section with more hard angles. No idea if it has an impact but an aftermarket line should allow more brake fluid with less resistance. All of the above should theoretically result in a smaller engagement window and quicker more natural clutch engagement and disengagement.

Take a look at the OEM line:



The snail looking black plastic thingy is the "swirl valve".

Not all aftermarket lines are long enough to delete it. I haven't tried them all of course but I can tell you that the KMD Tuning one is not long enough, and the ECS Tuning line is.

Tools Needed:

- Metric socket set (10mm and 13mm mostly)
- Small pick set
- Small flat head screwdriver
- Channel lock pliers
- 8mm wrench
- 1/4" ID clear plastic hose (optional)
- Fluid catch can (optional)
- Zip lock baggy (optional)
- Lots of rags (optional)
- DOT4 brake fluid


I cannot stress the small pick set enough. It will make the task so much easier. Something like this:



Step 1 - Remove Secondary Air Intake from air filter box. Pinch clip with fingers and slide off.



Step 2 - Remove intake hose clamp (with channel lock pliers, or similar), and remove intake hose.



Step 3 - Remove intake filter box by firmly pulling up and out. Set aside.

Step 4 - Remove battery cover and battery terminals. 10mm socket.

Step 5 - Remove battery retainer bracket. One 13mm bolt. Then remove battery and set aside.



Step 6 - Remove battery tray. 4x 10mm bolts. The 3 vertical ones take completely out. The 4th one that's horizontal by the firewall you just need to loosen and the battery tray slides off of it. It will be obvious how this works when you've done it.



Step 7 - Remove the clutch line from the bleeder block. Pry up clip with pick or small flathead screwdriver where blue arrow is. Pull clutch line out and be prepared to catch dripping fluid in a zip lock baggy. I'd put down some rags as well in case you spill.



Step 8 - Remove clutch line from clutch master cylinder. This is the tricky part! Mostly because it's not an easy reach. Again, use the picks to manipulate the clip. In the pic, try to separate the ends of the clip where the blue arrows are, and then pull from the green arrow side. It was hard to get my camera in there. Again, it's one of those things where it's not that complicated, but hard to see what you're doing. Be prepared to catch leaking fluid here as well. Do not lose the clip! You'll need it to reattach.





Step 9 - Install the new line the opposite way, refitting the clips. Make sure the original O-rings came off with the old line, and that the new line has O-rings installed. Run the line under the transmission mount. Below you can see it installed.



Step 10 - Bleed the system. You don't have to, but life is much easier if you use a speed bleeder for this. It's basically a one-way valve so you can let fluid and air out, but air can't get sucked back in. The idea is to get ALL the air out that you introduced by emptying the line. The bleeder screw is on top of the bleeder block. Remove the cap and attach your plastic tubing here. Should be a tight fit.





If anyone wants to use a speed bleeder, this is the one I got and can confirm fits:

https://www.amazon.com/gp/product/B000C5C71S/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

The bleeding process is as follows:

- Open bleed screw (turn with 8mm wrench)
- Open brake fluid reservoir
- Top off with brake fluid
- Pump clutch pedal by hand 10-15 times. Fluid should start to flow out your plastic hose
- Watch the fluid in the hose or have a friend keep an eye on it. If you see little fizzy air bubbles, there is still air in the system
- Repeat until fluid coming out is solid with no bubbles

IMPORTANT -- keep brake fluid reservoir topped off with brake fluid the whole time. I would refill every 5 or so pumps of the pedal. If you don't, air will be sucked into the system through the top and you'll just be in an endless cycle.



Once the fluid is solid, close the bleed screw. Pump the pedal 20-30 times to fully pressurize the system. It might be stuck to the floor at first and take a little bit to build resistance but after 20 pumps or so it should feel normal again and spring back.

That's it!

A few important notes:

If you don't use a speed bleeder, a slightly different bleeding method is required and you'll likely need a 2nd person.

You don't have to delete the "swirl valve". You can plug the stainless steel line directly into it, if you prefer to leave the delay in your system.

I'll maybe do a review on the line later after I've driven it a little more.

Nice writeup for the guys who haven't done this yet.

It's an oscillation damper, it has nothing to do with delaying clutch engagement. all it does is absorbs any vibrations in the clutch line. See here: https://www.fte-automotive.com/en/products/clutch-hydraulic/vibration-canceler.html

This is a ‘bling’ mod. It doesnt help with anything. The only thing you gain is less reliability.
Ive installed few of these on various cars and nothing is gained. A year or two down the line, youll see dirty fluid because the inferior materials has degraded. One of my friends actually ruptured after 4 years of use. OEM rubber lines can go 10-20+ years!

Same goes with SS braided brake line.

Tigsel said:

It's an oscillation damper, it has nothing to do with delaying clutch engagement. all it does is absorbs any vibrations in the clutch line. See here: https://www.fte-automotive.com/en/products/clutch-hydraulic/vibration-canceler.html

Click to expand...

Pedal feel is more direct after removing it. It's an obvious difference and sure feels like quicker engagement, but I'm not going to sit here and swear that's the case if that's not what the part is designed to do. Even if it induces no delay it still has an impact on pedal feel and is not just a placebo effect.

20ls01 said:

This is a ‘bling’ mod. It doesnt help with anything. The only thing you gain is less reliability.
Ive installed few of these on various cars and nothing is gained. A year or two down the line, youll see dirty fluid because the inferior materials has degraded. One of my friends actually ruptured after 4 years of use. OEM rubber lines can go 10-20+ years!

Same goes with SS braided brake line.

Click to expand...

I wouldn't call it a bling mod considering it's under stuff in the engine bay and you never see it...

Even if the benefit of a steel line is minimal (although I could feel a slight difference with my KMD Tuning line), the primary benefit on the Mk7 is deleting the clutch accumulator valve, in my opinion. Although I suppose whether it's beneficial or is debatable and depends on how you want your clutch pedal to feel. I hate how uniform and soft feeling the pedal is, so any little improvement helps in my book.

But I have to disagree with the reliability comments. I was never concerned about longevity with the stock line. It's half metal anyways. But I ran my KMD line for over a year and my brake fluid still looks new. The ECS line appears to be quality and uses OEM o-rings etc. Unless you've witnessed their clutch line failing en masse I wouldn't make the assumption that the materials are inferior. Personally, I'm not worried.

What happened to your friend's line, it actually split open? Or just started leaking? Know what brand it was?

Tigsel said:

It's an oscillation damper, it has nothing to do with delaying clutch engagement. all it does is absorbs any vibrations in the clutch line. See here: https://www.fte-automotive.com/en/products/clutch-hydraulic/vibration-canceler.html

Click to expand...

"The additional benefit is that the increase in release travel improves clutch life
by reducing the amount of time that the clutch is dragging during transitioning
between engaged and disengaged when the driver depresses and releases the
clutch pedal. This significantly increases clutch life, especially for "street driven"
vehicles which see lots of stop and go traffic which causes the most
wear to clutches."

"There will be some vibration when the clutch is depressed. However, even with
the factory clutch there will be better clutch engagement feedback (Honda must
have known something by eliminating the clutch damper for the NSX-R)"
- Science of Speed

http://www.nsxprime.com/forum/showthread.php/161442-new-product-focus-Clutch-Damper-Delete-amp-Hose-Kit

nicholam77 said:

Pedal feel is more direct after removing it. It's an obvious difference and sure feels like quicker engagement

Click to expand...

I deleted the swirl valve 1000 miles ago and agree with both you and Science of Speed

I had already done the OEM bleeder block delay valve removal mod but picked up the ECS clutch line and the ECS bleeder block for relatively cheap so I finally installed them both last night. I also removed the "swirl valve" or vibration damper.

I was skeptical at first but so far the shifts do feel noticably better/smoother. However I can definitely feel the vibration through the clutch pedal. Hopefully I'll get used to that.

I don't think this is an essential mod but for $60 for the clutch line on it's own it is probably worth it if you're looking for a better shifting experience and can accept the vibration. I'm not sure how much difference the $130 ECS bleeder block makes especially if you've already modded the OEM one. Certainly that money could be better spent elsewhere.

Just as a side, my clutch line came with a black clip to anchor it somewhere. Where did others secure this clip? The OEM line also had a clip but I couldn't get it out.

Sent from my SM-G950U1 using Tapatalk

There is a spot for the clip, but I don’t remember exactly where. I did not attach mine, however. I don’t think it’s a big deal if you don’t. My KMD line didn’t come with a clip and had no issues.

bigdave79 said:

my clutch line came with a black clip to anchor it somewhere. Where did others secure this clip? The OEM line also had a clip but I couldn't get it out.

Click to expand...

It replaces the clip for the OEM line under the trans mount. Just use pliers. You won’t need it again so don’t worry about hurting it

Dang, the pictures don't seem to show up anymore. Any possibility to get them back? Seems like a great DIY guide!

^^^ I can see all the pics, try clearing your cache and reload the page