clutch engagement point moves up as car warms

Post by **EstoMax** » Fri Aug 22, 2008 9:29 am

Hey Guys,

I have an interesting issue that i started noticing after replacing my clutch master cylinder (old one's metal bracket broke that connects to the clutch pedal). Anyways, after that, when the car is cold, i have several inches of free play on the clutch pedal, and as the car warms up, the clutch engagement would get closer to the top of the pedal ( i would have to press the pedal less the disengage the clutch). On hot days, it moves all the way up and I am thinking the throwout bearing is getting undue wear because of this.

Since my master cylinder was new, i tried to bleed the system again, but that didnt help. So i figured that the only other component in the system that is old is the slave, so i got a genuine Nissan one and replaced it - no change. My only guess left is that the clutch master cylinder that i got from NAPA is being a POS.

any input? i have removed the damper system so air in that is not a culprit.

thanks in advanceMarko

Post by **scottydog** » Sun Aug 24, 2008 3:54 pm

The only thing it could be is a bad master. Take it back and exchange it.

Post by **97240SE** » Mon Aug 25, 2008 4:31 am

Mine does something similar, when it warms up, or mostly at night for an odd reason, the clutch pedal engagement point gets closer and closer to the floorboard, but the clutch pedal also stays down farther so at one point I may have 3 inches of pedal travel. Im assuming my system needs to be bled but I havent gotten to it.

Post by **EstoMax** » Mon Aug 25, 2008 5:04 am

97240SE wrote:Mine does something similar, when it warms up, or mostly at night for an odd reason, the clutch pedal engagement point gets closer and closer to the floorboard, but the clutch pedal also stays down farther so at one point I may have 3 inches of pedal travel. Im assuming my system needs to be bled but I havent gotten to it.

your problem seems opposite of mine, your engagement point moves down toward the floor, mine moves up towards me.

I think i'm gonna order a genuine Nissan master cylinder and hope that does the trick! That way i have new clutch components all around.. better not have a problem for another 100k

Marko

Post by **EstoMax** » Mon Sep 22, 2008 7:53 am

well i put in the nissan mc, and for a week everything was dandy. Now it started doing it again. ill bleed it again but i have no idea what the hell could cause this. i have a new mc and new slave, both oem nissan from the dealer, and just hard line between the two... @#$@#$

Marko

Post by **Spectre_240sx** » Mon Sep 22, 2008 12:49 pm

I've got the exact same thing going on with my '90. I actually replaced the clutch thinking it might have been the pressure plate, but that didn't fix it. I've got a new (within 6 months) master and slave and a stainless steel braided clutch line. I haven't removed the damper box yet.

The big thing I'm trying to figure out is if it's in the hydraulics or something else. maybe something going on with the fork?

Edit:

Looks like there are a lot of people having this problem. 2g DSMs apparently had a problem called "pump-up". This occurred due to poor adjustment of the clutch rod. If the rod was adjusted so that it's too far out, there's a valve that will never release and pressure just keeps building every time the clutch is depressed. I don't know how our cylinder's compare, but it sounds pretty close.

Here's a link: http://www.roadraceengineering...h.htmCheck 3/4 down the page.

Some others:

http://www.3si.org/forum/f35/c...97157/ ... tchadj.htm -- This one looks good.
Modified by Spectre_240sx at 12:34 AM 9/23/2008

Post by **grecco28** » Mon Sep 22, 2008 7:28 pm

ok, i have the same problem wiht my 92 ' the thing is when i replace the clutch master cyl. when i run the car for 10 min i feel exesive adjustment almost to the point then i barely touch the pedal and the clutch disengage,so i take the time to figure was going on...i check everything you can imagine actually i removed the tranny to check the pressure plate... ok i solve the problem making small adjustments to the rod. once per time i drive the car to my job i loose a little bit until i get the desired free play.. some times its feels a little harder the it should be but i kick the pedal full stroke a few times and come back to normal..

Post by **EstoMax** » Tue Sep 23, 2008 5:43 am

wow thanks for the reply spectre.. You make a lot of sense because for the first week i didnt adjust the clutch rod, so thats why it didnt have any problem (but i didn't like having an inch of empty clutch travel before any pressure started on the pedal). After adjusting the rod and pulling the clutch up this started happening. I'm reading through those threads now... damn thing!

I hope i didn't rape my thrust bearing on the crank too much by having this happen.. oil analysis came back great last month. (i let this happen for about 2 months, but it would only top out on hot days) KA24's are more stout than the 4g63's i guess:P

I'll play with the clutch adjustment and keep you all posted!Marko
Modified by EstoMax at 8:55 AM 9/23/2008

Post by **Spectre_240sx** » Tue Sep 23, 2008 7:37 am

I made an adjustment to my clutch last night. As I was turning the rod, I felt a release of pressure (no jokes please ), It felt good when I took it for a drive after the adjustment, but when I got into rush-hour traffic it pumped itself right back up again. I'm going to take a look at the adjustment again tonight once it's cooled down and see what it's doing.

Post by **1mansho** » Fri Oct 10, 2008 7:39 pm

I have the exact same problem! I just put in a exedy stage 2 and the pedal is soft and engagement is closer to the floor when its been sitting. When the car warms up to operating temperature the pedal is more firm and less play which i want and engagement is higher.. I hope its nothing major and is normal.

Post by **snowdrifts13** » Sat Oct 11, 2008 9:09 am

i have a similar problem i replaced my clutch and flywheel but my pedal when its cold is all the way up and my clutch disingages about an inch into it. as i drive the pedal moves further and futrther toward the floor and i have tp pull it back up with my foot underneeth it and the process starts all over again. when its warmed up its worse and 3rd and 4rth grind when i downshift and i just put new syncros in when i did my clutch and clywheel. i looked at that link and is my pedal a 1g or a 2g?

Post by **snowdrifts13** » Sat Oct 11, 2008 9:14 am

also i forgot to say i dont know if this happened because i didnt adjust the clutch or whatever, but the fork that the slave cylinder presses on to disengage the clutch, and the thing i dont know what its called the thing that you press into the throwout bearing, that was all messed up i had to replace the fork and the thing that presses into the throw out bearing because the fork had like grinded it so that the fork would get crooked on it. sorry if i didnt explain that vary well.

Post by **Spectre_240sx** » Mon Nov 03, 2008 6:59 pm

Snowdrift, you've got classic symptoms of a bad slave cylinder. Replace it and bleed the system and you should be all set.

Post by **EstoMax** » Mon Nov 17, 2008 9:06 pm

just wanted to pipe back in that the moving clutch engagement point got taken care of by adjusting the clutch pedal engagement point down lower a bit. Now i have about an inch before solid pressure on the clutch pedal but the engagement point stays constant.

Marko

Post by **johnnyballs180** » Tue Nov 18, 2008 2:43 pm

i recently started another thread about this same issue.. i didn't realize it was a repeat.

so, Marko, you're saying that adjusting the rod so that there's a little more freeplay eliminated the problem? i flushed my clutch hydraulic system, removed the dampener box, checked all seals, but nothing changed.

i DID, however, instal a new clutch/flywheel a couple months ago. after it broke in, i adjusted the clutch pedal juuuuust a tad; i went from +- 1 inch to roughly 1/4 inches, and that's when the trouble started.

a couple days ago, i also lowered the pedal, thinking that when i adjusted it out, the problem started, so if i put it back in a little, the problem might go away.. and it helped, but not much. i get worried when i drive, that i might have constant pressure on the clutch. i would pull over on the side of the road when the pedal was rock-solid, so i could adjust the pedal down a bit. but when THAT happened, the engagment point changed, and i'd have a couple inches of free play.it's like i can't win

is your pedal still holding?

Post by **stratmatt777** » Tue Mar 20, 2012 8:50 am

I realize this is an ancient thread, but I am having the EXACT same problem.

I replaced my master and slave cylinder (unneccesarily since it made no difference in making it easier to shift gears). I bled it fully, but the car behaved exactly the same- still hard to shift...
So then I had the clutch replaced and was told that the clutch had 40% left on it, but was a "Cheap dyson clutch".

When I picked up the car from the mechanic the pedal was really low on the floor and I adjusted the pedal to get it home (the shop was closed), but it builds up pressure after 20 minutes of driving and then the clutch is slipping.

So... my engagement point is low at first and then moves up after 12 or 15 minutes so that the pedal is hard and slips.

Last night after 15 minutes of driving the pedal got hard and the clutch was slipping so I backed off the clutch pedal adjustment a couple turns... just when I got it perfect and was about the tighten the lock nut the pressure suddenly bled off and the pedal went too low so I had to adust it back up almost to the point it was at when it built up too much pressure and started slipping on the freeway.

This has been going on for a week- it is like groundhog day! HELP!

Post by **supermario680** » Sun Mar 25, 2012 1:48 am

Ugh, good lord... Finally someone had th correct answer. NO you master/slaves are not bad...

The problem IS In fact due to not enough free play at the top of the pedal due to improper adjustment.

The pushrod needs to FULLY retract to allow fluid to return to the reservoir.

If fluid cannot return then the fluid will expand as it heats and push on the slave more raising the engagent point...

clutch engagement point moves up as car warms

clutch engagement point moves up as car warms

Re: clutch engagement point moves up as car warms (EstoMax)

Re: clutch engagement point moves up as car warms (scottydog)

Re: clutch engagement point moves up as car warms (97240SE)

Re: clutch engagement point moves up as car warms (EstoMax)

Re: clutch engagement point moves up as car warms (EstoMax)

Re: clutch engagement point moves up as car warms (EstoMax)

Re: clutch engagement point moves up as car warms (Spectre_240sx)

Re: clutch engagement point moves up as car warms (EstoMax)

Re: clutch engagement point moves up as car warms (EstoMax)

Re: clutch engagement point moves up as car warms (snowdrifts13)

Re: clutch engagement point moves up as car warms (snowdrifts13)

Re: clutch engagement point moves up as car warms (Spectre_240sx)

Re: clutch engagement point moves up as car warms (EstoMax)

Re: clutch engagement point moves up as car warms

Re: clutch engagement point moves up as car warms

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