CTR Clutch Delay Valve Removal

natethegreat

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I installed all of Acuity's products except for the short throw adapter in hopes of getting rid of the clunky shifter feel with not much luck. I also put in a weighted shift knob and that actually seemed to make it smoother. I still have a problem with 2nd gear, I have too wait for my RPM's to drop in order to upshift into second and that doesn't even to fix it all the time. The clunkyness seems to be affected by engine RPM. Has anyone got rid of the rev hang with HONDATA or KTUNER ? I feel like that combined with the CDV delete might be the way to go. Any thoughts ? I have not removed the CDV as of yet



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elmerzasty

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I installed all of Acuity's products except for the short throw adapter in hopes of getting rid of the clunky shifter feel with not much luck. I also put in a weighted shift knob and that actually seemed to make it smoother. I still have a problem with 2nd gear, I have too wait for my RPM's to drop in order to upshift into second and that doesn't even to fix it all the time. The clunkyness seems to be affected by engine RPM. Has anyone got rid of the rev hang with HONDATA or KTUNER ? I feel like that combined with the CDV delete might be the way to go. Any thoughts ? I have not removed the CDV as of yet
When did you last change your clutch fluid? I was amazed how shifting was improved after just flushing clutch fluid.
 

FK8_Ger

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When did you last change your clutch fluid? I was amazed how shifting was improved after just flushing clutch fluid.
Good idea.. After i removed the CDV and bleed the master cylinder with new brakefluid it never happened again with the 1st to 2nd grind... I dont know if that was the reason. But i can tell you all after adjusting the clutchpedal, put in a stiff pitchstopper and remove the CDV its a massiv difference ! The car should come like that from factory.
 

EnjoyDriving

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Oh, i thought you said it improved, but you got the grindings fixed by swapping the pitch stopper? If that's not the case, what issues did your pitch stopper fix?

Good idea.. After i removed the CDV and bleed the master cylinder with new brakefluid it never happened again with the 1st to 2nd grind... I dont know if that was the reason. But i can tell you all after adjusting the clutchpedal, put in a stiff pitchstopper and remove the CDV its a massiv difference ! The car should come like that from factory.
 

alejandroads123

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The clutch delay valve is located inside of the clutch slave cylinder to slow down the engagement of the clutch to reduce shock to the drivetrain. With correct clutch control, the CDV is not needed. Instead it interferes with the operation of the transmission.

My certified pre-owned 2016 V6 Accord 6spd MT had a clutch that always felt direct, in control and with feedback from the drivetrain. By comparison, the CTR felt numb. The first owner removed the CDV from the Accord.

CDV removal on the CTR is easy with the exception of one hard step: removal of a metal retaining ring to get the CDV out. The ring needs to be in one piece so you can put the slave cylinder back together. It took me 45 minutes to get off :banghead: :banghead: :banghead: :banghead:.

Damaging the inner walls during extraction of the CDV is possible and you would not be able to drive the car until the broken cylinder is replaced. If you first order a new slave cylinder and remove the CDV, then you will get the hardest part the done first.

@Acurately posted pictures of opening the slave cylinder.
https://www.civicx.com/threads/the-infamous-2nd-gear-crunch.12890/page-43#post-362120

@gylmar814 Has a write-up for CDV removal on the Si and an explanation of what the CDV does and why you may want to remove it.
https://www.civicx.com/threads/clutch-delay-valve-delete-prl-ss-clutch-line-install-review.21587/

@PRL Motorsports has another write-up for CDV removal.
https://www.civicx.com/threads/10th-gen-civic-1-5t-clutch-delay-valve-removal.13105/

There are a lot of youtube videos on CDV removal for Honda MT. Previous gen civics and Accords have the same CDV. This video explains a technique to get the ring off and something similar worked for me.

Recommended tools for opening the cylinder:
Vice and clamps – hold the cylinder with the ring end up
Tekton pick and hook set – retainer ring removal
Needlenose pliers with teeth – pull out the plug
Drill and drill bits (1/16”, 1/8”, 3/16”) – CDV extraction

It is important to be careful once the cylinder is open. Scratching the inner wall of the cylinder can cause a fluid leak so don't use the needle nose pliers to extract the CDV. I pulled the CDV out by drilling into it and getting the drill bit lodged inside. Started drilling with a 1/16” bit and then 1/8” to widen the hole. Then I took a 3/16” bit and twisted it into the hole by hand using pliers. The bit got stuck and then pulled out the CDV.


Slave cylinder removal and installation
Part 1: Remove the air box.

Mishimoto has a video showing the removal of the airbox for their performance intake installation.
Unplug MAF
Remove rubber air duct and loosen bolts
You don't need to remove all the rubber stripping like in the video, only the part holding the air duct down.
Remove intake tube
Remove air box
The air box can be opened and taken apart if it makes it easier to get out. The rubber air duct also comes off. The air box clips into a bracket on the bottom.

Part 2: Remove clutch slave cylinder
First, locate the slave cylinder, clutch hydraulic line and all of the components listed below. See Parts diagram for numbers.

Clutch cylinder.png


Slave cylinder (7)
Steel tube (18)
Rubber hose (15)
Bracket (17)
Nut (23)

First find the slave cylinder.
IMG_7467.JPG

The slave cylinder (7) is attached to a steel tube (18). The other end of the steel tube connects to a rubber hose (15) that is mounted at bracket (17) using nut (23).

FullSizeRender 46.jpg

Do not bend the steel tube. Remove the nut indicated by the arrow and unclip the bracket to take the tension off of the steel tube. Now unbolt the slave cylinder from the transmission. Slip the slave cylinder out from behind the water hoses and pull it up. The rubber hose is long enough that you can pull the slave cylinder to the top of the engine bay. I tied the end of the steel tube near where the intake was so that fluid didn't drip out after removing the slave cylinder. Remove the slave cylinder using 2 open ended wrenches.

Connect the slave cylinder (with CDV removed) to the hydraulic line. Put the slave cylinder back onto the transmission case, clip the hydraulic line bracket and secure with the nut. Torque the slave cylinder bolts to 16 ft lbs.

Bleeding
Thanks to @Acurately for clutch bleeding procedure
https://www.civicx.com/threads/clutch-fluid-brake-fluid-reservoir.11380/#post-365829
Put a 8mm box end wrench over the bleeder screw and then attach a ¼” plastic tube. Follow bleeding procedure. Have someone sit in the driver seat to operate the clutch while you loosen/tighten the bleeder screw.
1. Loosen the bleeder screw.
2. Push clutch pedal in. The displacement of the fluid from moving the pedal will push the air out of the cylinder.
3. Tighten the bleeder screw.
4. Release clutch pedal. Pull it up from the floor it does not come back on its own.
5. Repeat. Make sure brake fluid does not go below minimum level.

@Fk8 4343 , I have read the whole post, I'm planing to do this mod, I already deactivated rev mach and also I swap the transmission oil for Amsoil, the transmission improve a lot, but still getting some crunchy gears, I would say the transmission improve like 70%, .
Any recommendation before to do this mod? the clutch fluid the level is on the brake assembly? or has separate circuit? When i bleed the clutch line should I paid attention to the brake level fluid?


Thank you.
 

typemismatch

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@Fk8 4343 , I have read the whole post, I'm planing to do this mod, I already deactivated rev mach and also I swap the transmission oil for Amsoil, the transmission improve a lot, but still getting some crunchy gears, I would say the transmission improve like 70%, .
Any recommendation before to do this mod? the clutch fluid the level is on the brake assembly? or has separate circuit? When i bleed the clutch line should I paid attention to the brake level fluid?


Thank you.
Clutch and brake have two separate reservoirs, the clutch one is the smaller one.
 

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I wish someone could make a video showing how the clutch behaves with and without the CDV. Like actually showing the pedal movements when driving and seeing the difference it makes.
 

mvela

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I installed all of Acuity's products except for the short throw adapter in hopes of getting rid of the clunky shifter feel with not much luck. I also put in a weighted shift knob and that actually seemed to make it smoother. I still have a problem with 2nd gear, I have too wait for my RPM's to drop in order to upshift into second and that doesn't even to fix it all the time. The clunkyness seems to be affected by engine RPM. Has anyone got rid of the rev hang with HONDATA or KTUNER ? I feel like that combined with the CDV delete might be the way to go. Any thoughts ? I have not removed the CDV as of yet
I have the ktuner and I changed the throttle response to level 2. This helps your throttle be more responsive. But by doing this, it also helps your rpms drop faster after letting off. So it does help out on gear shifts. You don’t have to wait so long to shift.
 

lorenkb

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@Fk8 4343 , I have read the whole post, I'm planing to do this mod, I already deactivated rev mach and also I swap the transmission oil for Amsoil, the transmission improve a lot, but still getting some crunchy gears, I would say the transmission improve like 70%, .
Any recommendation before to do this mod? the clutch fluid the level is on the brake assembly? or has separate circuit? When i bleed the clutch line should I paid attention to the brake level fluid?
Yes. Several things based on doing this last weekend. First off, patience is your friend. Nothing about this process is quick, and most of it is downright annoying.

Now would be a good time to install a SS braided line to replace the stock rubber line between hard lines (I went with PRL). If you do this, you must have the proper flare nut wrenches. The flare nuts are tightened to damn near yield. You will strip/deform the flare nuts if you use a regular box wrench. You need both 10 and 12 mm wrenches. I recommend skipping the 12mm nut until you have it off the car. The first nut/fitting is 10mm and is much easier to undo. Furthermore, you're going to need a pair of adjustable pliers or channel locks to hold on to the bracket that the flare nut/fitting is attached to. The bracket will bend long before the flare nut gives way if you don't. Once you've got the first 10mm fitting undone you can then unbolt and remove the slave cylinder and soft line as a unit. Be prepared to catch fluid from the remaining hard line with a ziploc baggie or other container.

Any work involving the slave cylinder is much easier to do off the vehicle. I'm going to go against all advise to date, and state that using a pick to remove the circlip is an exercise in frustration, futility, and wasted time. The slave cylinder is not built to be taken apart from the back end. It was assembled and drift pinned shut from the front. Digging a pick around until you hopefully get lucky and pull the circlip out is just going to foul the surface and make it more likely to tear the o-ring that seals the back plug. Devices that are built like this that are meant to be taken apart will have a slot cut in the perimeter for a prybar/screwdriver. Rotate the gap in the circlip to a point that makes you happy, and cut a small slot with a needle file or dremel cutoff wheel in the perimeter of the slave cylinder down to the depth of the circlip itself. You can then rotate one end of the circlip around until it's exposed by the slot and remove it with ease with a small flathead screwdriver or pick. Deburr the edge of the slot with a needle file prior to pulling/pushing the plug out. You do not want to risk cutting the o-ring.

Not having seen the internals before the mod, I assumed the plug had to be pulled out with pliers or a pair of picks. In hindsight, with the slave cylinder detached from the soft line, you can push a small diameter rod or pick through the front and push out both the delay valve and rear plug at the same time.

A pressure bleeder and catch bottle makes life mush easier if you're doing this alone. I used a Motive Products 101 Pressure Bleeder and Motive Products 1820 catch bottle . Kind of a pain to attach to the pressure bleeder to the reservoir, but once you've got it on, it works well. Apply pressure, crack the bleed nipple, and watch for fluid to come out clear.

Clutch and brake have two separate reservoirs, the clutch one is the smaller one.
No, it's not. There is a single reservoir on the Type R that feeds both brake and clutch circuits.
 
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coopermidnight

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I did a CDV delete in my Si because clutch engagement was severely hampered, especially during 1->2. However, I've had no such problem with the Type R. This clutch feels like the Si's did after the CDV was gone, and that's the way a CivicX member advertised the car to me.

What's everyone else experiencing?
 

lorenkb

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I did a CDV delete in my Si because clutch engagement was severely hampered, especially during 1->2. However, I've had no such problem with the Type R. This clutch feels like the Si's did after the CDV was gone, and that's the way a CivicX member advertised the car to me.

What's everyone else experiencing?
The Type R is the only car I've driven with a CDV. On the one hand, it seems to me that people are blaming the CDV for a whole slew of issues that could be resolved by adapting how you shift based on transmission feel. I've had zero issues stock, but I don't expect to be bang shifting through the gears like a dogbox. Cold morning shifts are different than when everything is up to temp, and waiting for RPMs to match between shifts is a thing. On the other hand, I much prefer the direct feel of the clutch with the CDV removed. I expected the Type R clutch to feel just like every other performance oriented vehicle I've driven, be it motorcycle or car, and the CDV added just enough of a vagueness to be noticeable. I adapted to the stock configuration, but I'm glad I got rid of the CDV.
 

alejandroads123

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Yes. Several things based on doing this last weekend. First off, patience is your friend. Nothing about this process is quick, and most of it is downright annoying.

Now would be a good time to install a SS braided line to replace the stock rubber line between hard lines (I went with PRL). If you do this, you must have the proper flare nut wrenches. The flare nuts are tightened to damn near yield. You will strip/deform the flare nuts if you use a regular box wrench. You need both 10 and 12 mm wrenches. I recommend skipping the 12mm nut until you have it off the car. The first nut/fitting is 10mm and is much easier to undo. Furthermore, you're going to need a pair of adjustable pliers or channel locks to hold on to the bracket that the flare nut/fitting is attached to. The bracket will bend long before the flare nut gives way if you don't. Once you've got the first 10mm fitting undone you can then unbolt and remove the slave cylinder and soft line as a unit. Be prepared to catch fluid from the remaining hard line with a ziploc baggie or other container.

Any work involving the slave cylinder is much easier to do off the vehicle. I'm going to go against all advise to date, and state that using a pick to remove the circlip is an exercise in frustration, futility, and wasted time. The slave cylinder is not built to be taken apart from the back end. It was assembled and drift pinned shut from the front. Digging a pick around until you hopefully get lucky and pull the circlip out is just going to foul the surface and make it more likely to tear the o-ring that seals the back plug. Devices that are built like this that are meant to be taken apart will have a slot cut in the perimeter for a prybar/screwdriver. Rotate the gap in the circlip to a point that makes you happy, and cut a small slot with a needle file or dremel cutoff wheel in the perimeter of the slave cylinder down to the depth of the circlip itself. You can then rotate one end of the circlip around until it's exposed by the slot and remove it with ease with a small flathead screwdriver or pick. Deburr the edge of the slot with a needle file prior to pulling/pushing the plug out. You do not want to risk cutting the o-ring.

Not having seen the internals before the mod, I assumed the plug had to be pulled out with pliers or a pair of picks. In hindsight, with the slave cylinder detached from the soft line, you can push a small diameter rod or pick through the front and push out both the delay valve and rear plug at the same time.

A pressure bleeder and catch bottle makes life mush easier if you're doing this alone. I used a Motive Products 101 Pressure Bleeder and Motive Products 1820 catch bottle . Kind of a pain to attach to the pressure bleeder to the reservoir, but once you've got it on, it works well. Apply pressure, crack the bleed nipple, and watch for fluid to come out clear.


No, it's not. There is a single reservoir on the Type R that feeds both brake and clutch circuits.


Thank you for the info, already did this whole process like two moth ago, the clutch definitely feels different ( engage and disengage point is more precise now) but this mod doesn't fix the 2 gear issue, still there, apparently the whole problem of the transmission are the synchronize , the only way to engage the gear without grind is just learn how to shift with this Type R transmission. The synchronize in this transmission has something week or different that is causing all the issues. My advice for now just try to learn how to shift with this transmission. I got amsoil, cable bushing, Slave cylinder delay delete. snifter bushing , all improve a lot the shifting experience but doesn't fix the problem. Just my experience.
 

alejandroads123

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I installed all of Acuity's products except for the short throw adapter in hopes of getting rid of the clunky shifter feel with not much luck. I also put in a weighted shift knob and that actually seemed to make it smoother. I still have a problem with 2nd gear, I have too wait for my RPM's to drop in order to upshift into second and that doesn't even to fix it all the time. The clunkyness seems to be affected by engine RPM. Has anyone got rid of the rev hang with HONDATA or KTUNER ? I feel like that combined with the CDV delete might be the way to go. Any thoughts ? I have not removed the CDV as of yet
Exactly, if you shift in the right range RPM according what gear you are at no problem, the rev hang play a big role in this movie if you shift low rpm the rev hang is worst that why we have grind also in low rpm and if you shift to high rpm to quick and spins the wheels you have grinds to, because the speed of the engine is not the right one for the gearbox.
 

Nitroturtle

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I don't understand how removing the delay valve would have any impact at all on grinds while shifting. If I understand correctly, the purpose of the valve is to delay clutch engagement after the pedal is released. All of this should be occuring after the gear change has already happened. What I would expect from removing the valve, would be a more crisp clutch engagement and elimination of the slight slipping clutch feel when applying heavy throttle immediately after shifting.
 

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