Advance1

I drive a ap1 MY02 and i've been trying to find everything on this problem but nothings seems to come up.
has about 105k miles on the clock

so my clutch gets REALLY soft almost like butter when i clutch down in between gear shifts after 6k rpm-9k rpm
i recently changed out my clutch master cylinder because it WAS leaking and check constantly the clutch fluid to make sure that its still holding up. Nothing seems to be wrong with the clutch master cylinder now (replaced only 3k miles ago) does not have the black grease and doesn't seem to be leaking because the fluid is basically topped off every time i check it. the clutch feels fine regularly when i drive normally just whenever i feel like gunning it the clutch feels really soft. but if i'm on the freeway for a good amount of time say cruising speeds of 60-75mph in 6th for over 15 minutes when i shift down to get off the freeway the clutch gets really soft again and i have to pump it a few times before it gets back to normal

so couple questions i'd like to ask

1.is this normal for the s2k/ap1 ?
2.could it just be that the fluids are warmed up after hitting vtec rpms?
3.or is it just air in my clutch fluid lines?

i plan on bleeding my clutch as well as fixing my sticky pedal within the next week or so, just wanted to make sure I figure out exactly what the problem is first. any information would be extremely helpful! thank you in advance

shamusodoofus

When you say your clutch feels soft, do you mean it is easier to push down than normal?

The OEM S2000 clutch is actually quite light. It doesn't require a whole lot of force to push down. I experienced a similar problem where my clutch felt "normal" when I drove it normally without pushing it. Every time I pushed the car or drove the car at higher speeds (in excess of 100+km/h) for an extended amount of time, the clutch would all of a sudden get lighter and be a lot easier to push down for the next maybe 5-10 pumps (when I push the pedal down). After several pumps the clutch would go back to "normal".

I eventually found that the "normal" feeling was in fact not normal. It was actually quite heavy this heavy feeling was caused by lack of grease and the development of a "nipple" formed on the slave cylinder by lack of grease. I greased up the slave cylinder, clutch fork and sanded down the nipple and the clutch is now lighter than before (which is actually how it's supposed to be). My guess is that when you push the car or when you're driving at higher speeds for an extended amount of time, the amount of vibration caused by the clutch fork to the slave cylinder heats up the grease and spreads it out evenly and then when you pump it a few times that grease then dissipates and you are once again pushing an unlubricated cylinder into the clutch fork which provides greater resistance and thus causing a heavier clutch that you may feel to be "normal".

Please understand that I can't be 100% certain that this is your issue. From your description, it appears to be very similar to an issue that I had before and following the steps outlined resolved it.

*Here's the DIY guide to reapplying grease to the slave cylinder and sanding down the nipple that has formed
https://www.s2ki.com/s2000/topic/370...-clutch-pedal/

Advance1

yeah it seems that this may be the problem, over the past week ive been noticing that the clutch has been sticking to the ground a lot more causing "sticky pedal", it would also appear that it is learning to this other problem. I plan on doing this diy within the next week and hopefully i can post back.

so just to make sure when you say "normal" is very "soft" after i drive for a while (over 100km/h) or push it the clutch pedal seriously feels like better though, almost effortless to push down and 0 resistance coming back up, is that considered more along the lines of normal?

s2k dre

I had the same issue! After i replaced the tube inside the tranny, the tube that the throwout bearing rides on. The pedal feel was perfect again. No more sticky pedal

shamusodoofus

Have you ever felt what the clutch feels like when there is air in it? I think the best test you can do, to make sure that your soft clutch is not air in the lines is to go to your nearest Honda dealership and feel what a stock clutch feels like on a car in the showroom (regardless of model). The S2000's clutch should more or less feel the same.

jpark

i have the exact same problem

shamusodoofus

Regardless or whether or not it fixes your problem... I would check your slave cylinder first and use the DIY guide. See if this fixes your problem. If not, this is perhaps one of the cheapest maintenance you can do on our car and you won't be out much (except maybe 1 hour of time) and maybe $5 if you don't have high-temp urea grease lying around.

RWDlover

Ressurection, better than starting a new topic. I have the very same issue, pedal gets soft after revving my Ap1. Clutch master cyl. is replaced with new, doesn't leak, checked the slave, it doesn't leak a drop, slave is properly greased with Honda urea grease, but the problem is there. Does anyone know what exactly is causing the problem?

Slowcrash_101

It's not a problem, centrifugal force makes it easier to disengage the clutch. The flywheel stores inertia from the crank and bleeds it out to the clutch. That's partly why the clutch slips at high RPM(when it's going out), and why shifting is easier at higher rpm, particularly when you have disengagement issues.

RWDlover

I don't think it's normal for various reasons, one is it doesn't always do it. For example, a few nights ago i launched it from 7k rpm (first time ever), and then did 2 roll races, and the pedal had consistent weight all the way. Then, a few nights later, i do a roll race from 2nd gear, and by the time i shift to 4rth, i feel the pedal is butter soft. This can't be normal