One step closer to selling it.

[CP]

I got home yesterday barely able to shift the car into gear.

for some reason, I've had to screw the clutch rod into the master cylinder about a turn every month for the last few months. The engagement point keeps getting closer to the floor. No leaky slave boot, not much weep from the rubber stopper o nthe back of the master cylinder, bled it 3 different times, stainless line.

For the last few weeks, the engagement point starts on the floor, then moves up near the top during my 45 minute commute. In between, it moves all around. I've got the rod screwed about as far into the master as it'll go, evidensed by the fact that I can barely see the end of the rod because it's turned so far into the clutch pedal connection.

WTF is going on here? My last OEM master cyl did the same thing, so I replaced with this stock 1G unit sometime late last fall. I've ordered a new unit from Advance Auto, hoping that a manufacturer switch may produce better results.

I've never seen the inside of a master cylinder, but is it possible that the rod is screwed too far into the cylinder bore, resulting in something funky going on with the plunger/stopper/seal, producing the moving engagement point I've experienced?

Could crankwalk be an issue? I'm pulling the transmission this weekend to swap in my spare and inspect the flywheel/clutch parts. Could a loose pressure plate cause this? I'm f***ing fed up with this car, and am driving my track car to work for now, which sucks donkey balls and isn't all that safe to do.

 

[GVR-4]

Dude, tell me about it! I'm having the same trouble. The next thing I'm going to do it switch to the bigger (green) slave cylinder to see if that makes a difference. I just looked under the dash last week and when I push the clutch pedal in, the pushrod goes into the master cylinder a good 1/4 inch before I feel any pressure plate action through the pedal. What's up with these crappy clutch issues with this car? I've been trying to sort it out for about three years!

 

[jepherz]

You have enough problems with your car, which should be expected when modifying past a tested product put together by engineers with hours of testing while using possible knock-off parts. Sell the damn thing and get another Miata if you truly think it's the CAR...

With that said, per your description, since the pedal engagement gets further up as you drive the car, it sounds like it HAS TO BE a hydraulic issue. There are then 3 main parts to this system; master, slave, and the lines that connect the two. To answer your question about the master rod being extended into the seal, no, that's not possible. You have mentioned that you've tried numerous master cylinders to no avail. That leaves either a leak in the line somewhere or the system isn't fully bled, or something is up with the slave cylinder.

Have you tried replacing the slave? Looked for leaks around there? What is the status of the lines?

 

[CP]

I replaced the slave with the OEM unit when I did the master last fall. It appears to be working fine. The lines all look good; no leaks or sinking fluid level in the reservoir or fluid coming from any of the components on the ends.

The lack of fluid loss has led me to believe that it's a problem with the master. Anyone have a diagram that illustrates the parts inside of it?

(I like to complain alot when I can't figure out a problem, and this qualifies. Another Miata, no. But something to tow it on a trailer with may be the GVR4 replacement once I'm driven over the edge by the next issue that's bound to pop up soon)

 

[jepherz]

Your description tells me that the fluid is going somewhere, obvious or not. I don't have a diagram for you but a master isn't all that complicated. You should be able to pull it out and figure out how it comes apart.

Have you checked underneath the slave piston boot for leaking? On the inside of the cabin for leaking from the master?

 

[Muskrat]

You said you've checked the master and slave, and they look ok. Check the line. Stainless steel lines aren't leak proof. Don't rule anyting out until you've checked it over thoroughly.

 

[CP]

Will do. F'ing car.

 

I'm curious to know how this plays out as someone I know is having the same problem. Which clutch setup do you have? Check if the rod in the slave is bent or broken.

 

[Hksvr4]

Did you check the play of the pedal? It could be that you need to replace the clutch pedal assemebly. This problem haunted me for years. If you were to follow the clutch pedal assembly you would locate a bolt at the end of the rod. It's usually above the gas pedal. That bolt comes loose and causing the clutch pedal to have play. A quick fix, is to tighten the bolt with a 14 or 12 socket. I forget. Most likey you have to replace the assembly. Which I did. I welded the nut on to the new assembly. It sucked cause it took alot of hours.

btw, you can replace the slave, master, line a hundred times and still have the same problem. Trust me, I've done it.

 

[CP]

ClutchNet Red 2x pp and the ClutchNet sprung 6-puck, with a 2G stainless line to the slave cyl.

Currently I have to start the car in reverse if I want to use reverse, and even so it creeps a little bit with the clutch pressed down to the floor with excessive force. Shifting coming home yesterday was horrendous, which is why it's sitting in my front yard and I'm driving the Miata for the rest of the week with ear plugs. Shifting got better with refv matching and some double clutching, but that's a pita and it still ker-chunks into gear. I'm trashing my built Shep tranny, and can't wait to see how much the magnetic drain plug has picked up when I drain it on Friday night.

I've also had it with the mainstream trans fluids we all seem to gravitate towards. The spare is getting SWEPCO-201, an OEM/recommended fluid for Porsches. I think running a shockproof mix for the first year after getting my trans back from Shep killed the synchros, now that it is known that those fluids don't work well with brass.

 

[CP]

Quoting Hksvr4:
Did you check the play of the pedal?



Hmmm, not yet. The pedal did have some side to side movement that it didn't used to have when I was kicking it yesterday. Are you talking about the rod adjustment bolt, or some bolt that holds the pedal assembly to the firewall/underdash?

 

[Rausch]

It's not uncommon in other applications, for the fluid to push past the diaphragm in the master, this, without getting to the point of leaking externally, would change the total 'throw' of the unit, and move the engagement point. Albeit a bit a time.


As stated above, Maybe get it out and apart, and see what's what....That would be my guess....

 

[Hksvr4]

Quote:
Are you talking about the rod adjustment bolt, or some bolt that holds the pedal assembly to the firewall/underdash



If I can recall, it's where the clutch pedal return spring is located.

 

[464/2K]

just sell it, sounds you like ate some whaabugars and french cries /ubbthreads/images/graemlins/banghead.gif

 

[CP]

Yeah, I've been eating that for about a year now /ubbthreads/images/graemlins/applause.gif

 

[kartorium]

When I had issues like that it turned out to be the clutch pedal assembly. Mine was actually broken in half and was causing the firewall to flex which made the travel of the rod really inconsistent. When the pedal was depressed the master cylinder would actually get pushed into the engine bay a little bit causing the actual stroke of the rod to be greatly reduced. As the problem got worse I kept having to adjust the pedal, then finally I realized the bastard was broken.

Does your firewall move when you press the clutch in? Have someone watch very closely. Does everything squeak and grone when you press the clutch? If you have these two symptoms I'd say the assembly is causing your problems.

What I have described is entirely different from the typical pedal assembly problems. The typical problem comes from shaft that the clutch pedal rotates on IIRC.

If you are thinking that the master, slave, and line are fine, then it pretty much has to be this.

sh*t, you might also check to see if your transmission is pulling away from the block when the clutch is pressed in. Watch very closely for movement, this would cause similar problems.

Other than that I spose the bolts could be undone on the pressure plate /ubbthreads/images/graemlins/dunno.gif

 

[AWDnot2]

Quoting 464/2K:
just sell it, sounds you like ate some whaabugars and french cries /ubbthreads/images/graemlins/banghead.gif



Def Leppard sucks!

hahaaa. Joe Dirt rules!

 

[CP]

Just ordered a new pedal assembly just in case. It's cheap ($70), so I figured I may as well replace it now since I've already done most of the rest of the car since I've owned it.

 

[Hksvr4]

I rather do a clutch R/R instead.

 

[Olson]

CY ive been going through the same problems but to an extream. i have a fidanza fly wheel and a 2900 act setup . after doing some pulls and dataloging the clutch let go. the friction center section completely let go. the cause was an over throw of the clutch pedal be extreamly carefull to not get to much throw other wise the pressure plate fingers will come in contact with the friction plate. i guess this is a common problem with the act seires clutches. so i went with an exedy unit and the fidanza fly the problem just started to come back i could HEAR the fingers making contact with the center section. also the fly wheel warped on my. At this moment im putting in a RRE no name 11lb flywheel. Also prior to putting in the exedy i replaced the slave and master and put an a extended rod on the master cylinder fixed the problem but had to much throw. also i think the fidanza flywheel wasnt steped right for the setup i had. My pedel box is the orginal one but has NO play in it at all. so hopefully the correct steped flywheel and all fresh clutch compnets are good. Also have a braided line with a teflon coating on it that was pressure tested at some crazy # .

i think the next step for me is a new pedel assembly and looking at the fire wall like someone mentioned.
I to am at the point of selling but you know what. I know whats been replaced on the car i know what shoulD NOT brake and there shouldnt be anything else that can brake with all the parts that have been replaced or upgraded. but its all so a 17 year old car and its going to have more maintiance than a 5 year old car.

Good luck CY i feel your pain