Is the 6MT Slave Cylinder Delay Valve Delete Harmful?
 

Hello everyone. I'm a college student who has had a 6MT 3G TL for quite some time. I love the car but holy crap I feel like a newb every time I shift from 1st to 2nd. My other shifts are usually okay, but 1st to 2nd is always bumpy. The only way I ever get it to shift smoothly is if I baby it when I disengage the clutch, but then that ends up making me drive super slowly haha.

I'm seeing that there is a valve that delays engagement of the clutch, and I'm interested in removing it. However, I found this thread on a Civic forum (link attached) where a user wrote that

"You guys do realize that this valve keeps the pressure from blowing the seals over time in upstream part of the system right? It's there to control the pressure feedback when the pressure plate springs release. With it out there is a pulse of high pressure back into the system that puts a lot of extra pressure on the clutch master cyl seals. This valve controls that flow to even out the upstream pressure. Honda puts it there for a reason. This lil trick has been around for a while and I have personally replaced failed parts because of it. It's not like the engineers at Honda put extra crap in there just to hinder performance on the car. If this was a reliable way to run the system i'm sure they wouldn't have included it. By doing this mod you will prob see premature seal failure and will prob end up sitting on the side of the road when the seals fail and the clutch won't engage. Just some food for thought."

I had no idea this was the case. Have any of you experienced bad effects of the delay valve delete? Any advice?

Thanks

i've had my car for 9 years with the delay valve deleted for about 7 or 8 years.
my master cylinder is working just fine

:woot: in Feb 2020, i'll have had my car for 10 years!

My CDV was only done a year ago; from a mechanical perspective, unless you are constantly banging gears and popping the clutch, then there will be no adverse issues with the CDV.

That's good to hear. So removing it is definitely worth it?

Is it hard to remove the slave cylinder? I've never worked on my car and my dad told me it's a difficult operation.

Attempting to make those perfect shifts with the valve in place makes it more difficult while putting more wear on your clutch and drivetrain than if you had just removed that valve and had a more predictable friction point in the clutch travel. I've had mine removed over a year with no problems. Don't go banging through gears like it's stolen.

One of the best thing I've done to the car. Probably 200k on the clutch since it was done.

Delete the check valve and get it re-tuned. Hondata will improve the feel of the shifts.

Not having the check valve can put extra shock through the transmission but its not going to kill it. I VTEC every day and have not had an issue.

I’ve had mine out for probably 6-7 years and no issues at all. Still on original clutch too 126k miles

Whoa! You’re still around with the TL? Siiick. Is the TL still constantly on jacks? 😂

KTuned has these slave master cylinder delete mods but none specifically for the J (not the last time I checked anyway). So I’m confident it’s not that big of an issue to worry about unlit as you’re REALLY rough and/or really bad at shifting.

Thank you for all your comments. It's really good to hear that you all have no trouble.

Does anyone have a master source for removing the slave cylinder? I've been searching for guides and youtube videos but I'm finding that all of these sources are leaving out details like tools. The job is intimidating me but I don't have the cash to get a mechanic to do it haha.

It’s a straight shot in the engine bay I think it’s two bolts

:rofl:

:pofl:

i figured out the trick; if i dont mod it, it wont break!
I havent touched it in the last few years , meaning i'm done modding!

will also need a second hand for bleeding the clutch. unless one can devise a device to hold the clutch fork, like a short block of wood

There is a guide to removing the Check Valve on this obscure thread.

https://acurazine.com/forums/3g-tl-p...harger-965385/

Only thing harmful about the CVD is loosing races knowing you could have otherwise won.

looser move.

The only effect you will see on CVD is the motor mount will get torn earlier (like the OEM one lasted anyway).

Can confirm. Had mine deleted for several years now (idk, like 5?). Just changed the clutch fluid a few weeks ago - no leaks anywhere or any other issues. Just don't dump the clutch to prevent excess hydraulic pressure and large, sudden loads on engine mounts. Shifts are more predictable (note: they aren't easier, necessarily, just more predictable). This mod doesn't cure bad driving. If anything, it will punish your mistakes more severely. BUT at least something that has a predictable feel is capable of being learned.

did you do a full bleed or just replace the fluid in the reservoir...debating doing mine as well

Replace the reservoir fluid twice and it’s no different?

I had the mechanic at the dealer flush the entire system not one but twice, we half joke "you got the cleanest clutch fluid in town". The pedal feels definitely better, oh to top that off he also re adjust the pedal point of engagement, the pedal feels good now.



Back to the question of CVD.

Stock form - you will eat motor mounts
bolt on with sticky tires - engine mounts and axle will paying for it.
mods with sticky tires, upgrade axle, motor mounts along with stage 3 clutch - your 2nd/ 3rd gear will living in borrow time.

Full bleed. I just bleed the slave, while topping off the reservoir, until the fluid runs clear. I think I used about half a bottle to get it all the way through.

CDV delete is a must. And learning not to drop your clutch wrong. One time I did a vacuum bleed no problem. 2nd time i had a problem. Now I will only do the 2 person bleed for the clutch.