Papaman677

So I have an 05 6MT with 140k. When driving like a normally, everything is fine, shifts smooth etc. When I push the car hard, up to redline and shift, by the time I get to 3rd gear the clutch gets really hard to push in and tight. I searched around and found that it could be the clutch slave cylinder. I plan on having my slave changed out. My question is, is there any suggestion on replacement? One brand over another? I also heard about the check valve removal. Are there any slave cylinders that you can buy with the check valve already deleted?

Or if anyone else has had this problem, is it not the slave cylinder? My clutch doesn't slip at all and don't really think the clutch is the problem, but maybe I'm wrong.

truonghthe

I replaced my 05 with LUK and Centric, I would do slave and master cylinder at the same time. Its normal for the pedal got stiffer under WOT but not by a whole lot.

ACURAte_tiTLe

I had a similar issue with mine except the clutch wouldn't disengage at high RPM. I replaced my slave cylinder first (OEM) but it ended up being the master cylinder. Pull back the rubber boot on your slave cylinder and see if there's clutch fluid on the inside of the boot, if there is then it's leaking and is probably the source of your problem. The master cylinder typically fails internally and you won't be able tell visually if it's bad or not. That was the case with my car. Also check your clutch fluid level.

There's also another thread here https://acurazine.com/forums/3g-tl-p...h-rpms-630049/ that suggests the clutch pressure plate might be at fault. I ruled out a clutch issue in my case because the problem went away if I pumped the clutch pedal before starting the car.

If you do end up replacing the slave cylinder, do the check valve delete while it's brand new. It's kind of a pain and having a used one covered in grease and dirt will only make it harder.

HVAC34

i second this. I had intermittent clutch problems it turned out to be the master.

Papaman677

I was hoping it wasn't the master, hear that's a much bigger job. Usually when I rip through the gears it gets much more hard to push and feels like it comes up slightly slower. Once I start cruising again the clutch is fine. If I drive normally, the clutch is fine. I did watch a few videos on the check valve delete and it looks like a PITA. Too bad they don't sell it with it already deleted.

DMZ

When it comes to the clutch master cylinder, go with the OEM brand, Nissin if you can find it outside of having to go to an Acura dealer for it. Avoid the aftermarket ones. LUK is good for the clutch kit, it IS the OEM clutch after all, but not for the clutch cylinders.

Again, I speak from experience!
.

BROlando

It doesn't make any sense for this issue to be related to clutch hydraulics.

I'm not sure why a slave or master cylinder going bad would cause this issue.

This is how the clutch hydraulics work:

• you push the pedal
• the pedal pushes on the master cylinder rod
• fluid moves from the master cylinder, thru the lines, and into the slave cylinder
• the piston in the slave cylinder pushes on a rod
• the rod pushes on the clutch fork, which releases the clamp load on the clutch so you can shift.

The hydraulics don't clamp the clutch together. A mechanical spring set does. The hydraulics only allow you to release the clutch pressure.

When you let go of the clutch pedal, a spring clamps the clutch together so that power can transfer to from the engine to the trans.

So....why would air or any leak cause the clutch pedal to be HARDER to push? Air compresses. Liquid doesn't.


This is almost surely a mechanical issue with the clutch itself. The release bearing rides on a guide sleeve or guide post. If someone used the wrong grease....or worse yet, used antiseize to lube this, then the bearing will score up that sleeve and build up a "lip" of dried up metal shavings and clutch material, held together by paste remaining from the grease.

Idk if there's an access point, but if you can spray white lithium grease at that sleeve, the problem will temporarily go away. This will mean you have to drop the trans and get all that serviced.

Never never never use anti seize on a clutch spline or release guide. And not any grease will work on a low friction clutch system.

Its very important to use the right grease - most likely Honda HT Urea grease.

BROlando

If the clutch has never been serviced (meaning, if nobody has had the opportunityto use the wrong grease), there is a chance that water affected the guide sleeve - driving thru a big puddle or parking the car in a big puddle, or....normal wear of the guide sleeve may be the culprit.

Some other things to consider may be broken or worn clutch mechanical parts.

Most threads with these type of issues see a total resolution once the clutch is replaced.

Like magic.

Papaman677

Yes, I'm the original owner, got it June 7th 2005, so I know the clutch has never been serviced, it's still on the original clutch at 140k. The clutch itself doesn't show any signs of slipping and hope I dont need a replacement, I just spent a decent amount of money replacing my suspension, tans fluid, oil change and finally got my airbag light taken care of....but that was covered from Acura. I came up with the slave cylinder after googling around and searching around on here. I can slam through the gears and with the VSA off can still spin the tires going into 2nd gear, so the clutch isn't slipping and going up hill in a higher gear there's no slipping. But maybe it's something else within the clutch system like you said.

HVAC34

Dude I literally did a whole swap with new clutch and the clutch problem from before persisted. It was the master cylinder. Maybe the seals seat/unseat or the diaphragm loses effectiveness intermittently, I’m not sure but my problem is gone now. 🤷‍♂️

BROlando

Your clutch was hard to push at high RPM due to a failing master cylinder seal?

From what I understand, that's the OP's issue.

You didn't quite specify what issues you had with your clutch.

HVAC34

I had “intermittent” clutch problems. With only a few thousand miles on the clutch.

it would not disengage the clutch all the way.


At high rpms there’s more centrifugal force on the transmission input shaft making it harder for the OP’s clutch slave cylinder to actuate. If it’s not the slave it’s the master 99.9%

Bars

140k miles on original clutch.

I went through the same as you. Replaced master cylinder and slave with delay valve delete. Helped, but problem persisted. Clutch did not slip either. replaced clutch and flywheel and problem went away.

Start with the slave/master cylinder then work your way up. Like BROlando said, it’s most likely not the slave/master cylinder, but it’s cheap so whatever. I would get a cheap slave cylinder from rockauto since it’s so easy to switch out. But for the master cylinder, i’d go oem or exedy since it’s a pain to do. I’ve never worked on cars prior to my tl and I did the slave cylinder with delete by myself and had help from a friend with the master. This was 3 years ago. It’s pretty easy. After replacing those you’ll realize that you need to save up for a clutch job. And then you get it and then the problem is gone.

DMZ

Papaman677, why not call Paul, our star master mechanic who also happens to be in Clifton, NJ? He's right here and will straighten out your situation, GUARANTEED! He's replaced my clutch cylinders and the only mechanic allowed to touch my car. Being in the same town, I can't believe you haven't used him.

PM me for his contact info.
.
.

Papaman677

I'm not in Clifton anymore, grew up there, not that I"m far now, but good to know. I go to my friend and he's been great with all my cars.

DMZ

But so far, not apparently great enough to fix your current problem. Where do you live now?
.
.

Papaman677

I haven't brought it in for this problem yet, was trying to get an idea on my own, trying to get an idea of how much it would cost, how big of a job it would be. If I drive civilized then the car is fine. Totowa

BROlando

Look at the OP's issue.

Its not that the clutch won't disengage. Its that it becomes hard to push.

Centrifugal force is engine RPM dependent. Not speed or gear dependent. And the centrifugal force that affects clutch disengement effort is on the pressure plate leaf springs...not the input shaft.

It doesn't make sense for his issue to be hydraulic.

But...hey, maybe there's a tiny chance that something weird is happening. Clutch master/slave cyls are cheap and easy compared to a clutch. So as a shot in the dark, it may be good to inspect/replace.

But a 99.9% bet? that's strong.

Again...

you likely have something wrong with the release bearing guide or clutch itself.

I'd have the car looked at by a qualified technician.

I'm just some guy on the internet. You don't know me, and I may be a complete imbecile.

HVAC34

The issue only happens when redlining/hard shifting I think he’s referring to RPM when he says redline.

MyGuti

I have a similar issue, if I drive spirited, rpms 4k and higher, the clutch will begin much more "tighter" and the disengagement and engagement points different than before. Its happened to me a couple times, but I dont drive like that often. After a little while, the normal feel of the clutch returns.

BROlando

...bruv....yes, it happens at redline, but check the specifics below...

The centrifugal force related to parts that the HYDRAULICS affect is the same at redline in any gear, or any wheel speed, right?

Whether he's in 1st, 2nd, 3rd, 8th, 20th gear, the pressure plate spins the same speed as the ENGINE.

So...Why doesn't it happen in 1st gear? Or 2nd gear?

The input shaft is also moving at ENGINE speed before he pushes in the clutch pedal.

His problem is different than yours.

His issue likely has to do with a slow return or partial misalignment of the release bearing due to a guide sleeve problem. Not centrifugal force.

A couple of hard, rapid shifts in...the bearing is still in some dislodged state and makes the pedal difficult to push.

Shifting at a lower RPM doesn't upset the release bearing position as much, and giving time between shifts allows the bearing to re-center itself. The bearing is always spinning at the same speed as the pressure plate.

That's the most common reason for his issue, is all I'm saying. For this to be hydraulic related would be bizarre.

Assuming I'm understanding his problem correctly.

truonghthe

Just replace the CMC and SC for now, its solve the issue on my 05 sunken pedal after high RPM pull, as far as the clutch goes our TL has a weird clutch and I expect the age has some thing to do with it as well. In my KBP I never had experience any symptom as in my 05, also noted the KBP got a brand new clutch/flywheel, throw out bearing and pilot bearing in the Dec of 2019.

oraclem20

So a viewpoint that seems to be getting overlooked here about the hydraulic/centrifugal argument, is that if the higher engine speed is increasing the centrifugal force on the pressure plate, the hydraulic system then therefore needs more force to move said pressure plate. If the seals are leaking in any amount on the CMC or SC after 3 shifts at a raised hydraulic pressure due to the increase in centrifugal pressure it must overcome to disengage and engage the clutch the leak would have had 3 times to move fluid to the wrong area of the cylinder or introduce air into the system somewhere decreasing its ability to shift at the same hydraulic point on the pedal. It could be everything, it could be one thing, and honestly the only way to definitively tell is to take each hydraulic out, attach it to a gauge, then run it through a series of tests to verify its pressure exerted per inch. Then take a set of stock ones, test those per inch, and compare your numbers. Additionally you'll need to introduce a force gauge into the system to measure the hydraulic force needed to overcome the possible additional centrifugal force adding to the normal force of the pressure plate preventing disengagement and determine if it is escalating exponentially with RPM.

Or.... you could replace <$100 worth of parts that is recommended to be replaced about every 100,000mi for spirited drivers. I think I have an extra CMC without the check valve in it laying around that was used for 50miles, and a stainless steel connection to replace the soft line between the hydraulic hard lines on the transmission if you'd like to pick it up. Upgraded to a 3/4" bore Wilwood master cylinder for clamp force and bang bang clutch pedal shifties. Girls don't like the harshness of the engagement, but it keeps them from wanting to ride in my car, which lets me drive faster, so I say just upgrade to a 1" bore Wilwood and call it a day otherwise.

BROlando

Why would a hydraulic leak (internal or external) make the pedal HARDER to push?

Hydraulic bypass would release the pressure.

Less pressure in the same area would mathematically tie in to lower force.

You're saying that centrifugal force increases pressure (???), but at the same time, a leak which releases pressure is to blame for a harder clutch pedal??

And why would a bigger master cylinder or slave cylinder make the clutch clamp harder??? The hydraulics only release the clutch. You push the pedal...and hydraulic fluid RELEASES the clamp load. The clamp load is provided only by the mechanical springs in pressure plate. Hence the name...pressure plate.

Also...who are these girls???

BROlando

The only way this could be hydraulic part related is that there is a sticky seal inside the slave or master cylinder.

But...if that seal makes it hard to push the pedal, the pedal should also be slow to return, and the clutch would also slip because it was not being allowed to re-clamp.

OP stated his clutch is not slipping.

Just that the pedal is hard to push down after rapid high RPM shifts.

Y'all can take it from here.

The chances of this being fixed with a new slave and MC are very low.

Most people who have had THE SAME problem have fixed this via clutch replacement and/or fixing the snag on the guide sleeve.

HVAC34

Ok man. It’s THE CLUTCH

BROlando

You're moving in the right direction! congrats!

But its more likely the guide sleeve for the release bearing. Just try reading a little more carefully. I believe in you.

HVAC34

Bro I was being facetious. The fact that the op isn’t even answering shows me this thread is dead.

I could go on and talk some more but for what. At the end of the day the op probably won’t report back.

so.... let’s all agree it’s the clutch

oraclem20

Its the clutch, definitely without any question or explanation. Agreed. Just ask Acura expert BROwhateverthefuckyourname is. He's so emphatic about this problem that isn't his he must be right. I wish I could be that excited about anything, I probably would be if I had ever learned anything about mechanics or cars. I aspire to be like BROfuckhead someday.

BROlando

Well, shit eh!. My bad.

Well, hopefully he reports back. Be interested to see how he fixes it.

You've got a bit to go...but keep trying. Firstly, just remember that the hydraulics doesn't clamp down the clutch. I have no idea why you're even mad. because I gave you info, my bro?

HVAC34

I’m sorry didn’t mean to be a douche. I just really want to know about this issue/fix because different people have different claims on this story.

I overthink sometimes and I’m linking this to the “Infamous” third gear grind in our 6spd it has to do with 3 gear.

i know cdv delete cures this I’ve seen it happen 2-3 times back and forth swapping slave cylinder (with all else being top condition i.e. hydraulics and clutch.) I notice that with delay valve in it grinds if you don’t wait like a whole second before you gas after disengaging clutch/engaging clutch pedal.

if the op comes back let’s chit chat some more about things we’ve seen and done to this exact generation of car including what part was changed and what effect it had.

HVAC34

Like I’m willing to entertain the idea that it could possibly be hardware related. But it’s some how also related to 3 gear grind. There’s a lot of rotating mass with speed by third. Let’s get to the bottom of this.

Papaman677

Haven't been around to comment. I did have the 3rd gear pop out/grind probably a few months after i bought the car. Acura ended up replacing the 3rd gear syncro which didn't fix it, but switching to Syncromesh did. So everyone seems to think it is the actual clutch. For anyone who replaced it, how much did that cost? Labor/parts....OEM, the car is stock so no need for an upgraded clutch. I also just spent a decent amount replacing my suspension not that long ago. If it is the clutch I'll just have to watch how I drive it for now, as I said it's find unless driving the car really hard, the clutch gets harder to press by 3/4th gear. Assuming a clutch is about a $1500 job? Would be nice if it was the MC and slave, would assume it's not as expensive as an entire clutch.

HVAC34

Alright your on. Now it’s your turn to do your part of the thread. Start replacing components lol

BROlando

Me either, bruv. Respekt


OP, maybe u can work with a shop that lets you take photos of what they find?

I'd kinda want to do this myself. But I'm a dummy

Papaman677

I looked on youtube for videos thinking maybe I can do it myself.....and yeah.....I'll end up making things worse. I will update this when I end up bringing the car in.

truonghthe

clutch replacement is around $1500-$2100 job. The LUK kit is cheap even with new flywheel, if you do replace the clutch make sure buy OEM throw out bearing and pilot bearing and get the rear main seal service as well.

DMZ

Make sure to get a new flywheel to go with the new clutch. According to LUK tech support, the manner in which the clutch wears happens to correspond with the wearing of the dual mass flywheel, and as such, they recommend a new flywheel whenever replacing the clutch.

Replacing a clutch? Replace the flywheel too and save yourself some aggravation down the road!

Take it from my 1st hand experience with this!
.
.

truonghthe

what urge me is that you spending all of time to remove the trans and subframe only skipping out on the flywheel. LUK dual mass is like $250.

DMZ

$206.79 at rockauto to be precise. The more expensive ones ARE the LUK flywheel repackaged and rebranded for more money.
.