Tommy Gunz PSIU

iTrader: (1)

So i posted awhile ago about having a problem with my clutch pedal. The problem only seemed to be happening when I would be going fast (not crazy fast, just normal fast). What was happening was that i would start to push my clutch pedal down, and it would need almost no pressue, and then I would feel pressure about midway down. The faster I went, the further down that pressure point would be, until eventually there was no pressure point, and my pedal was at the floor (so my clutch would not disengage). After getting all the comments on my previous post, I decided to get the heavy duty CSC, and replace the clutch and flywheel at the same time (got the Southbend stage 1 combo, and its awesome). After i did this, THAT PROBLEM WAS FIXED!!!. This was all done probablly around 6ish months ago and was done by a local mechanic.

My problem now is that the problem is coming up again. This time it seems to have no bearing on my speed, but I do feel like the longer I drive the car (in one trip), the lower that pressure point gets. I have not experienced it going all the way to the floor with no pressure (yet), but I definitely dont want to have it get to that point.

Here is what is happening... I start the car and everything is fine (clutch feels normal), as i hit lights, or change gears, i slowly start to feel that pressure point get lower and lower. I get home, wake up the next morning, and everything is fine again, and the process continues.

I also should tell you that i checked the clutch resivoir and the fluid seems to be clear, but there is some black gunk in it.

So my question is this: Do you think that the CSC went bad again (keep in mind I got the heavy duty one), or does this sound like a master cylinder problem. Or even maybe does this sound like air in the lines? There doesnt seem to be any fluid leaking, as the resevoir hasnt seemed to move (although I havent checked it that recently) and I dont see any thing leaking (I know i wouldnt see anything if it was the CSC).

Any help would be greatly appreciated, and sorry about the novel, but I know the more info you guys have, the more it helps.

JSolo

iTrader: (14)

Was your MC replaced the same time the CSC was? From all the readings i've done, it seems to be a recommended item at the time of replacement (although much easier to replace than the CSC).

I'd probably start with a good thorough flush/bleed, see if that helps. Use a dot4 fluid.

I've got about 18 months on my car, but low miles (~7500 miles to date), both brake and clutch fluid look as clear/clean as they did when new. I plan on bleeding the brakes next spring and will do the clutch fluid at the same time.

Tommy Gunz PSIU

iTrader: (1)

The MC was NOT replaced when I did the CSC, which is why I'm kind of hoping its just the MC, and not a CSC issue. I definitely plan on doing a flush (even the lines were flushed when they did the CSC), the issue is that i cant replicate this problem every time i drive. For example, when I went to work today, everything was fine... everything felt normal the whole drive.

I'm sure I'm going to be able to replace the MC myself, the only reason i didnt do the CSC was because i dont have a lift. Do you know if there is any way to diagnose if the MC is bad, or do you think I should just flush the lines and then update this post if the problem continues?

Black Betty

iTrader: (60)

The CSC isn't failing. Black sediment in the bottom of your MC reservoir is evidence of likely MC problems. Change it out and rebleed the system throroughly.

Tommy Gunz PSIU

iTrader: (1)

Awesome. Thanks BB. I'll order it right now. It seems that this is also a pretty common problem on our cars. Do they have a heavy duty MC? lol

Black Betty

iTrader: (60)

I wish. If they did, I'd have one. Actually two.

Tommy Gunz PSIU

iTrader: (1)

Just ordered the MC. I'll keep you posted. Thanks again guys.

Phimphasone

iTrader: (3)

I had the exact same problem, I also have the new MC but it has not been installed yet, I didnt have the time to install it yet

however what i did to fix my problem. I completely flushed out the old clutch fluid, cleaned out the CMC reservoir with a paper towel and made sure that the whole entire system was bled properly with clear fluid running through the system. The whole process took me about 30minutes to do with a new bottle of brake fluid.

And now my pedal is back to normal and I havent had a problem since then. I ended up sending back the new CMC and saved my self $100 also note that my car has 125,xxx miles on it currently (my daily driver). You might want to try it out and see if it works for you.

Tommy Gunz PSIU

iTrader: (1)

Well I'll definitely be flushing the whole thing as well, but I figure I might as well get the MC changed out anyways so I know that I'll have a basically fully new clutch system. I just hope this gets everything worked out, cuz its sooo rough trying to feather the clutch out when you only have 1/2 inch (or what feels like 1/2) of play. I stalled out yesterday lol. I havent dont that since.... I pulled the car off the lot lol. (OK... maybe a few lights too HAHA). I have the rev around like 3K to pull off, and because there is so little room before the clutch bites, its not the smoothest thing on earth.

Phimphasone

iTrader: (3)

well the new MC should fix your problem, FYI its a bitch to install... and I know exactly what your talking about, my pedal was the exact same way and it was not fun....

Tommy Gunz PSIU

iTrader: (1)

How Did you Get This Thing Out... What Did You have To Take Out???

IMTASE

There is actually a Infiniti tech bulletin regarding clutch pedal not returning properly. The repair is to use fluid from the GTR.

Tommy Gunz PSIU

iTrader: (1)

Phimphasone.... I hate you lol. When I saw your comment about this being a bitch to install, i just thought to myself... "he just must not be very mechanically inclined, becasue the FSM makes this seem like to problem"... WELLLLL... I apologize for thinking that way about you lol. It would have been very easy had it not been for the ABS box, and the brake booster being in the way. I spent ALL DAY just trying to get that thing out. I literally took the whole brake booster out, and had to take the brackets for the ABS box off just to get the old MC out. It wouldnt have been a problem if I could have taken the hard lines going to the ABS off, but I wasnt about to mess with that. BUT..... The new MC is in, and the lines are flushed, and it feel AWESOME! i love the consistency. That was done on Saturday (i couldnt believe how fast that part came in). and then on Sunday I did my trans and diff oil. Car runs like a dream now I guess it was a gift for my car hitting 60K miles. Oh, i also finally put on my aluminum ZSpeed Undershroud (for under the engine bay)... Thanks to ECain18 for the hookup!

Next up...
-New tires (I think I'm going with Hankook Ventus V12 evo k110)
-Powder Coating Rims
-Powder Coating Brake Calipers
-Try to squeez in some time to build an enclosure for my sub.