posidon42

iTrader: (4)

My car is immobile right now and I need your help diagnosing the problem.

Car details: 99 w/ FMII, ACT HD 47k miles.

Previous symptoms:
Over the past week or two I have noticed some heat related issues with the clutch. As the car heats up the clutch engagement position changes. When cold, the clutch picks up maybe an inch off the floor with smooth pickup. When warm, the engagement point moves to maybe an inch from the end of the clutch pedal travel. The engagement is almost much more binary (off/on) when it is warm.

Today:
Went out to get some breakfast today. The car was cold and in the garage. The place I went to was only 2 miles away and I noticed something was strange right away. The clutch pickup was almost immediately off the floor and it was VERY quick. Modulation was very difficult. I get to my destination and couldn't down shift. It just wouldn't go into gear. After waiting over an hour for the two truck, it is now back in my garage.

Diagnosis help:
1 - When I got to the place, I smelled hot clutch fluid, but there were no leaks. I checked everything that I could and there are no apparent issues with the clutch master cylinder. I can't get to the slave cylinder without jacking up the car.
2 - I changed out the clutch fluid maybe two months ago ~1000 miles. It is now VERY dark and I check the fluids all the time. I suppose this is something that happened recently. I can post some pics if needed.
3 - The clutch will not disengage and there is no pedal pressure on the clutch. It just goes to the floor with what feels like spring back pressure. Definitely no hydraulic pressure.
4 - The clutch reservoir is full of fluid.
5 - The master / slave are the original units

I can't work on it today since my four year old is having a birthday party. But I would like to have a plan of attack and some sort of diagnosis plan. Hopefully this isn't an actual clutch related problem, but I installed the ACT HD myself, so I can take it off again if absolutely necessary.

Thanks in advance for your help.

Mach929

iTrader: (3)

my bet is on the slave cylinder. mine did the same thing but never leaked a drop onto the floor. but when i touched the rubber boot it was full of fluid

posidon42

iTrader: (4)

That is my thought as well. Should I get a new one or just rebuild this one?

curly

iTrader: (25)

yup, slave cylinder. happened to me and I had to drive home 30 miles by shifting without the clutch. had to start from a stop with the starter, luckily I had disabled the clutch starter switch

curly

iTrader: (25)

rebuild kits are kinda sketchy I've heard. a new one is only $30-50, just get a new one

Toddcod

iTrader: (8)

So there is fluid in it?
Sounds like The slave or master cylinder went out. If you have a friend close I would just jack it up quickly, turn the drivers side wheel to the left, and your should be able to access it quickly. Have your friend pump it and see if the slave is engaging. If it isn't engaging properly, then you know it is the slave or clutch master cylinder.

If it is engaging fully and strong, you have other problems.

Sometimes you can bleed the slave and cripple the car for a little bit.

If you are stranded and have to get home. In this case I start it in 2nd and wind it up high and then pull it into 4th. I don't force it....... No it isn't good. But it will get you home. Sometimes it works better if let the rpms fall some when you get it into neutral. You'll find out when you try to find 4th.

Good Luck

Toddcod

iTrader: (8)

Dang. Everyone posted fast. Anyway buy a new one. If you have the extra cash, replace both. When one goes out it usually isn't long before the other.
It could be either one as well.

neogenesis2004

iTrader: (12)

I just bought the master/slave combo on ebay. They are working great.

A lot of times when your slave goes out and you replace it you end up with a dead master soon after. Just replace both at the same time. Also get this clutch line: http://advanced-autosports.com/image...tch_Line_L.jpg
It is the best thing since sliced bread. With it you can bleed your clutch in seriously like 6 pedal strokes.

posidon42

iTrader: (4)

I see there are lots of brands available for the replacement parts. Any recommendations to purchase or avoid?

Not trying to be cheap, but this combo at $45 for both looks ok: http://cgi.ebay.com/ebaymotors/Parts...3756.m14.l1318

posidon42

iTrader: (4)

scratch that last link, the picture doesn't match what is on my car and I don't even see a reservoir for the master cylinder.

going to go check the slave cylinder now. Be back in a couple of minutes.

posidon42

iTrader: (4)

Well crap. There is no fluid in the slave cylinder and the slave moves just fine when the clutch is moved. I am in the middle of switching out all of the fluid. If that doesn't work, I am going to pull the trans and look at the clutch. Possible that the forks got bent or something?

Toddcod

iTrader: (8)

If there is no fluid in the resevor. Just add fluid. Changing the fluid will not fix the problem. Since there is no fluid in the device I would add fluid and bleed the air out. And it should work right. I think your slave is slightly leaking. they normally don't even leave drops under the car when they quit. There are rubber components that can fail and not hold the pressure of the fluid. It will push the slave some but not enough. The pressure will bypass back into the master cylinder.

Just my .02 cents. If the slave is dry, theres a 98% chance thats the problem. Add fluid and bleed system. Checking fluid levels as you bleed it.
Once bled. If it works right replace the two components.

If it doesn't work right then have a friend pump it and see how far it moves. Then put a Cresent wrench on the lever and see how far it is actually supposed to go. And compare to see if it is moving far enough.
If the resevoir was dry you probably have air in your system.
Taking the tranny down would be my last resort.

If the throw out bearing was bad, It would be bad, Heat wouldn't of effected it.
Did the clutch ever slip?

curly

iTrader: (25)

yup if your slave rod is pushing the throwout arm in and out its something else for sure. I also had that problem, ended up being a bad throwout bearing. that would cause the dead pedal feel cause you wouldn't be pushing against the resistance of the pressure plate. could also be the pressure plate. time to pull the engine and trans.

oh and as for the ebay link you posted, you re-use your reservoir on the new master, it just seals with an o-ring

BenR

iTrader: (2)

A bad master or slave could still move the pushrod a large enough distance you'd think it was working fine. Replace both the slave and master first. Then move on to the next possible thing.

Toddcod

iTrader: (8)

I could hear the throw out bearing in my last miata inbetween shifts and at red lights. I thought I would be able to sell the car before it went out.
Then two days before it sold, the clutch went to sliping too. I installed a new kit and sold it with a smile. I love $$$$$$$.

posidon42

iTrader: (4)

I tried bleeding the system and their was a bit of air in it, but it is the particles in the fluid that worry me. The attached picture is AFTER I ran two reservoirs full of new fluid through it. I don't know what happened, but I am ordering a new master and slave today.

posidon42

iTrader: (4)

so how bad does this look? It sounds like an abrasive is going through the lines when I am bleeding it. I might just take everything off this week while my new parts are en route.

neogenesis2004

iTrader: (12)

I don't know what that stuff is, but I know that its not supposed to be in there :P I still HIGHLY recommend that clutch line I posted the link for while you are at it. I know it looks expensive but it ROCKSSSSSS.

Also, were I you I would replace the master first and bleed the lines without the slave attached until I no longer saw those particles. Then I would add the slave into the mix.

posidon42

iTrader: (4)

Good point. I did order that clutch line you suggested. I hope it works as it cost me more than the master and slave cylinders

I am going to take this opportunity to cover most of the tubes in the car with some sort of heat protection and I am also going to build a more effective heatshield. Of course, if I get in on this group buy of the turbo blankets, I might be able to put my efforts elsewhere.

Sigh... the adventure continues. I just hope the master/slave fixes the problem. For some reason, I see myself taking the trans off in the near future...

neogenesis2004

iTrader: (12)

After you put on that clutch line you will thank me that it only takes you 1 min or less to bleed that clutch.