My car felt like it was losing some acceleration and it got worse as it heated up. Had trouble diagnosing it and was even about to pull the trans and clutch as I thought I might have glassed the clutch itself. After a bunch of reading on here it sounded like it may be the clutch master and/or slave going out. From what I read, they don't last very long and are hard to diagnose as they don't always leak when going bad. I'm pretty sure the pair were only about two years old and had about 4k miles on them.

Spent $18 total for a new Exedy Clutch Master and Slave on Rockauto. Took about an hour to swap out both and bleed the line.

The car is back to amazing and performing as good as ever. I'll be replacing the pair annually now. Thanks to everyone who posted up info about this, helped me a ton.

PS- don't forget to bench bleed the clutch master before install.

 

Yep. I replace the slave yearly. Master every other slave.

Ever Mazda i've ever had has had stupid short clutch hydraulic life.

 

How does an issue with the clutch hydraulics affect acceleration?

 

My clutch felt like it was slipping under hard acceleration. It wasn't horrible like if the actual clutch was bad, but enough to be noticeable. Maybe someone can explain the technical reason, but I think it has something to do with the fluid pressure not being as powerful as it needs to be.

 

The hydraulic system spreads the spinny bits away from each other to disengage the clutch. It does not push the spinny bits together to engage the clutch.

 

I don't know how to explain it then, but it is definitely engaging better. Is it possible for the slave to be messed up and not allowing full engagement?

edit: maybe it is the psychology of better pedal feel after the replacement.

 

Have you guys found one method of bleeding is better than another?
we have :
Power pressure bleeder
two person method
Reverse bleeding method
I heard reverse bleeding is used in the aircraft industry.
Anyway, if you've tried more than one way let me know what you think.

 

Yep. Placebo effect is where my money is.

All that said I fully agree that the miata master and slave cylinders are total ****.

 

I just replaced both on my car when the new engine went in. Its been my experience that the slave goes out much sooner than the master, but its good practice to replace both and its really easy anyways.

 

That's what research had told me as well so I only did the slave when my engine went back in. A few weeks later (with the car still on jackstands), the master leaked around the pushrod and into the car.

 

I've only ever had luck with the 2 person bleed method on any hydraulic system on any car I've owned.

 

First thing I thought when I read post #1- Thats not how our clutch works.

 

I hardly think the clutch master and slave are annual replacement items, unless you're somehow very hard on your hydraulics.

 

Yup, I'm a moron sometimes.