MX 5 Clutch issue

Ok, settle in. This is a long story.

Last week I'm at a track day near where I live. It's the fourth and last session of the day. The car, a 2006 MX5 with the 6spd, is running flawlessly. The only exception being I'm having trouble shifting to third sometimes. At the time I just chalked it up to being ham fisted. It always went in second try.

Now I'm coming on to the front straight and go for third. It will not go, so I try again, nothing. Feels locked out. So, like a yutz I give it a little umph to get it in. Sure enough I feel it slide in and let the clutch out. Here's where it gets ugly....turns out in my rush to shift I've stuffed it into first. As I feel deceleration and the revs skyrocket I stab the clutch back in. Now I can't get any gear, Im certain I've grenaded the gear box at this point.

In the pits the car seems "ok" in terms of no gaping holes or bad mechanical sounds, but the clutch pedal is on the floor. Someone suggest that I've probably boiled my clutch fluid and that's why the no go.

The MX5 uses the brake reservoir for the clutch slave as well, so if you boil the brake fluid it's possible to get air in the clutch slave I suppose.

Once the car cooled, it would drive and shift if you pumped the hell out of the clutch, so I figure a quick bleed this weekend and we're back in business.

Now the problem, I have bled the slave like four times now, I've done a gravity bleed, I've done a reverse bleed. The slave is NOT leaking.Clutch is still pooched unless you pump it a couple times before shifting. If you do that, the gearbox works fine and makes no odd noises.

Why won't this bloody thing work? Is it possible I collapsed the pressure plate? Or ripped the friction material? Why would it work fine with a bit of pumping, but just not want to bleed.Gah, I'm frustrated....!

That's a weird one.

I'm not sure what the problem is, but I don't think it has anything to do with boiling the fluid. The clutch slave is on the outside of the transmission bellhousing and won't get that hot even if you slip the clutch all day. If you do boil the brake fluid, it'll happen at a caliper and the vaporized brake fluid has no chance of getting back up to the brake MC then down into the clutch MC before it condenses again.

Clutch master cylinder has E36 M3 the bed. The cups in the M/C are worn, they not only do not seal properly under pressure but will allow air to suck in as the piston travels out, as in when you release the pedal. Usually this is accompanied by fluid coming out of the boot where the pedal pushrod goes in, but not always. Stick your head under the dash, look for the clutch M/C boot and pull it back with a O ring pick or screwdriver. If fluid comes out, yep it's toast.

There no visible leaking under the dash. I even pumped the clutch with my hand to see if I could provoke it. There's not an actual boot per say, but the shaft travels though a "gromet" held in with a cir-clip.

So if (and you'll forgive my layman's terms) the plunger part at the end of the shaft was done, but the "gromet" kept the fluid that got past it from entering the cabin, it is still feasible that the M/C is toast.

The car only has 40 thousand kilometers on it, seems premature.

What does the pedal feel like, and does the slave move as soon as you depress the pedal? If the pedal does not have a bunch of free play before feeling normal, and if the slave starts to move when the pedal moves the first inch, you've torn the facings off the clutch when you did the ol' second first full throttle upshift. On the upside, it may have saved the engine when it came apart.

I've done a 7400 rpm downshift in My Neon a couple of times. The first time, I thought I'd broken the tach, since it seemed to remain stuck at 9 grand for a very long time...

Pedal feels like it has very little resistance until the last couple inches before the floor. I supposed the clutch could be toast, but I'd like to cling to something simple for the time being. If you pump the clutch it feels 'ok' for the upcoming shift or when placing the car into gear. After a few moment, it goes back to feeling "soft" and engagement of any gear becomes difficult.

I may have to break down and take it to a shop. I hate to throw parts at it until it decides to work. It'd be so much nicer if something was puking fluid.....

Sounds like a hydraulic problem. Hydraulic clutches can be a real bear to bleed. If you are confident its bled properly, its likely time for a master.

Well golly, It's been two months and change, and I know you've all been worried sick about me and my car....

Without penning the next great american novel....

I had gotten under the dash and as a last resort adjusted the clutch pedal play via the threaded master cylinder rod. Voila, later engagement, but clutch now is working.

Drove it for awhile with the only annoyance being the release bearing squeaking periodically. Figured I'd just wait for winter and replace the clutch and such.

So I'm at an autocross last week, car seems very sluggish at launch, half way through the course something is clearly wrong. Engine making plenty of vroom-vroom noises, but car not interested in going forward.

Wrapping it up, get car home, pull the tranny and find this:

....now I'm no mechanic....

I must have damaged it way back at the track day, and it just finally said "enough".

I sure that's a load off your collective shoulders....again I apologize for the worry. Your church side candle light vigils and sleepless nights are over.

That one should go on the garage wall!