Clutch not disengaging

freshert · Postby **freshert** » Tue Sep 17, 2013 12:41 am

Hi there,
I bought my nb mx5 a few days ago and I'm loving it! However today, the clutch pedal just felt like it had no more resistance for about 3/4 of the travel, and the friction point moved down to the bottom of the travel. I kept driving and suddenly I couldn't engage any gears and was stuck. Luckily I was stuck right outside a mechanic and he had a look and said I'd broken the clutch.... I sat in the car for a bit looking under the pedals and then I looked at the clutch fluid reservior. The fluid was a dark green, almost dirty black looking. Assuming they use the same fluid for the brakes (orange/yellow) as the clutch, dark green seems like something is very wrong. I tried driving the car and viola, the clutch worked again and I could shift, although the friction point was still at the bottom of the travel. I parked the car and left it for an hour and a half, came back and the friction point was higher, I tried driving home and over the course of 18kms, the friction zone went lower into the travel until the car would creep forward faster and faster, sort of like a light automatic car (I couldn't change gears anymore so I kept it in third the rest of the way). So what I've determined so far is when the engine is cool, the clutch works better, the clutch fluid looks extremely dirty. There are no stains of clutch fluid on the ground when I parked. I've done some research and everyone seems to say the slave cylinder is leaking, but as I said earlier there are none I can see dripping on the ground, and the reservoir is constantly full no matter how much I pump the pedal. What do you guys think?
Sorry if this has been a long post, I've just been wanting a mx5 for about 3 years and now that I've got one I can't even enjoy those mini drift around roundabouts anymore.

I forgot to mention, the car has only done 45,000kms.

manga_blue · Postby **manga_blue** » Tue Sep 17, 2013 1:27 am

Sounds pretty much like typical clutch hydraulics failure - either the master or the slave cylinder or both. I don't like the sound of that mechanic. The cylinders don't really wear out - they rust inside and the seals in them just collapse instead if the fluid is not changed every 2 years. This is a bread and butter routine job for a brake and clutch workshop and shouldn't cost much if they just use generic replacement cylinders. There's not much sense in paying for genuine Mazda ones when it's just clutch bits. They're pretty basic technology and either genuine or generic will last for years when you look after them.

Repco or Bursons or someone like that would have the bits if you want to start doing things yourself. Replacing the slave on a car on stands on the floor is a nasty messy job though. Workshop manuals are in the Technical Guides section of this forum.

It would be worth asking them to flush the brake fluids at the same time and check brake pads and rotors too.

After that I'd have a close look at the car's service history and see what needs to be done to bring the rest of the car up to date.

Oh, and welcome to the forum.

JBT · Postby **JBT** » Tue Sep 17, 2013 6:02 am

freshert wrote:...I've done some research and everyone seems to say the slave cylinder is leaking, but as I said earlier there are none I can see dripping on the ground, and the reservoir is constantly full no matter how much I pump the pedal. What do you guys think?

I call BS on the mechanic and your research is correct. What manga_blue said.

"Pumping" the clutch pedal may get you out of trouble (keep a very close check on the clutch hydraulic fluid level though) to get the car to a clutch & brake specialist, otherwise it's DIY or put it on a flatbed.

The coolant has probably never been changed either and should be done every couple of years. Coolant and hydraulic service seems to get overlooked on older low kilometer cars.

freshert wrote:Sorry if this has been a long post, I've just been wanting a mx5 for about 3 years and now that I've got one I can't even enjoy those mini drift around roundabouts anymore.

You won't have the car much longer if you keep doing this. :wink:

project.r.racing · Postby **project.r.racing** » Tue Sep 17, 2013 9:07 am

could be a simple as air in the lines. any leaks are easy to notice. the slave can easily be seen from under the car if you jack if up. the master can be seen from looking up under the dash.

i recently replaced my master. it's been sold leaking for about 2 years. then one week, i had to fill the reservoir up twice. easy just to look up under the dash to see the fault.

but if you ain't loosing fluid, i doubt you have those issues. also check the rubber line to see if you have any ballooning in the rubber sections.

16bit · Postby **16bit** » Tue Sep 17, 2013 10:07 am

i have the same problem right now.

my slave cylinder was leaking so its def the slave and or master.

I am replacing both, i suggest you do the same.

I spent a total of 100 dollars for a new slave cylinder, rebuild kit for the master as it was not leaking, and a bleed kit with 1 way valve for easy bleeding.

www.mx5parts.co.uk is your friend in this situation.

and with 10 bucks of brake fluid that will rebuild the consumables on your clutch hydraulic system for less than the shop labour you would pay for someone else to do it.

from the reading i have done it really is a very simple job. the slave might be a little fiddly to get out but shouldn't be too hard.

broken clutch is a typical shop response as they will try to get your for a couple grand. they might even try to convince you they need to remove the engine.

emily_mx5 · Postby **emily_mx5** » Tue Sep 17, 2013 10:18 am

Try to stay away from mechanics that use such broad terms "the clutch is broken" oh yeah? What part exactly? Spigot bearing? Springs? Hydraulics? Next he'll be saying "broken engine" lol

Also try not to drive it, as you might damage clutch components, that are very expensive to replace.

Try a bleed with new fluid, maybe even twice if the old fluid is really bad.

Always start with the cheapest and easiest things first

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sailaholic · Postby **sailaholic** » Tue Sep 17, 2013 11:15 am

Pbr brake fluid is dark green from new.

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freshert · Postby **freshert** » Tue Sep 17, 2013 7:37 pm

Thanks for the reply guys. I have determined the problem to be the slave cylinder. It was leaking into the rubber boot.
I've replaced the slave cylinder with a new one but now I have a new problem, I can't bleed the system... I loosen the 8mm nut and put my bleeder on, but when I pump the clutch, theres no resistance and no fluid goes through. This is pretty frustrating.

hks_kansei · Postby **hks_kansei** » Tue Sep 17, 2013 7:57 pm

Keep pumping (you are closing the nipple before the upstroke aren't you?)

Since you've changed the slave there will be a fair bit of air in the system, it can take a fair bit to finally work some fluid through.

JRBasia · Postby **JRBasia** » Tue Sep 17, 2013 8:11 pm

Also note, if too much fluid leaked from the lines (ie all of it lol) like when I did it, you can pump till no tomorrow and no fluid will be pushes through.

Instead I ensured there was sufficient amount of fluid in the reservoir and used a small hose and syringe on the open bleed nipple to suck it through.

All you need is to fill the lines some fluid again and allow for pressure. Then you can pedal bleed (ensure all the air is now removed) like normal. Hope this helps you, don't be too worried. You're almost there!!

JB