About a month ago, I started noticing that my brake fluid was slowly leaking...I didn't see a leak, but the level would go down over the course of about a week until the light came on. I also noticed (didn't at first put two and two together) that sometimes my clutch would have a shudder to it as I would engage it, and sometimes it would act like there was air in the line...It would go practically to the floor, and the range of motion required to fully engage it would shrink drastically causing some pretty odd starts....then next time, it would be fine. Anyway, that clutch line that everybody replaces was pretty bad looking and had sticky fluid on it, so I replaced it with one of the braided steel lines. However, I'm still having the same symptoms. The weird thing is, I've looked at the slave and master cylinders, the reservoir, and all the lines I can see...no visible fluid anywhere. The slave was replaced about a year ago when I did my clutch, however the master is pretty ancient. But...if the master were the culprit wouldn't the source of the leak be obvious? It was bone dry.

Any suggestions here would be greatly appreciated!

jds

 

clutch slave cylinder bleed screw okay?

it's on the driver's side of the tranny

 

If the screw is tight and its not on the ground, time to overhaul the master cyclinder

 

The screw is tight and the entire area around it is clean.

I had the same thought about the master cylinder...however I guess I was expecting to look around and find brake fluid all over it, and it was dry as a bone. Where could it all go?

jds

 

could be leaking from your calipers/abs system/brake lines and could be affecting your clutch system.

 

Sounds like your master cylinder but could be anything Skunks said.

 

There is a flexible clutch line on the firewall near the tranny tunnel that is known to fail. Take a look there are replace it with an SS line if you find that it is leaking.

-Max

 

wait wait wait, did you test the master yet???

 

That's what he said he replaced...

Maybe you are leaking fluid from the back of the master cylinder, i.e. into the passenger compartment.

 

Eew, I hope not, sounds messy. As many times as I've had to top off the reservoir, I would think it would be obvious if it were in the passenger compartment, but I'll check it out.

I'll check out the brakes a bit more closely too. A cursory once-over didn't show anything, but I was sort of assuming it wasn't in the brake-specific part of the system since only clutch performance has been obviously compromised...but like most of my assumptions, they could well be wrong.

Thanks guys for all the suggestions!

jds

 

Master cyclinder can leak internally. here is a good way to check

Push in the clutch with the engine on or off. Hold it for about 20 secs, and if it gets softer and softer until it gets stuck on the floor, you just found your problem. Lot of times people just put it in neutral as stops which is good and will help prevent it from happening so often. So getting a new one from Mazda is like $200, correct me if im wrong. Anyway if you dont find any leaks, start at the slave (cheapest) and then go to the master and then it will be good. Always start with the cheapest parts first.

Checking the brakes is good too, but if they are leaking, they wont leak slow.

 

Thanks for the input. I tried that test and it doesn't do it all the time, but it does sort of partially do that. I also found that the area behind the clutch pedal in the cabin is a bit slimy...not enough to account for all the missing fluid, but I'll bet some of it leaked in there after all.

Mazdaformance quoted me $75 for the clutch master cylinder...not too bad at all.

Thanks a lot,
jds

 

Is fluid disappearing the back side or the entire reservoir. Reason being is the clutch uses the back side of the reservoir. Check that you are not leaking fluid from the slave cylinder (the side in the tranny). Pop open the inspection plate on bottom of tranny to see if that is where the fluid is going. I've been here before.

T.W.

Also you will not know of you are losing it from backside till it gets pretty low. About halfway if I recall.

 

My friend was having the same problem on his Miata. He thought he fixed it when he installed a new Slave cylinder and clutch line and repeatedly bled the system, but he had to top off on occasion and the clutch just never felt right. Air kept appearing in the system. There were no visible leaks for 6 months and then yesterday the slave cylinder finally gave out again for good and you can see a slight leak. No outward sign that the previous new slave was leaking, but it was leaking internally (bad seals).

I'd say it might be your slave.

 

Hmmm...slave looks perfectly clean from the outside, but I didn't open the inspection plate. AARRGGHH that will irritate me if its that. The slave cylinder is only about a year old. I am leaning towards the master at this point though, once I found evidence of some fluid in the passenger compartment in that general vicinity. We'll see...

jds

 

Master cylinders will leak internally, you may not see any fluid where you would expect it. It has a tendency to run out behind the vac booster onto the firewall thus remaining hidden from site unless you go looking with a flashlight

 

Oops, I didn't read the line replacement part.

$75 is pretty cheap for the master, but you can get a rebuild kit even cheaper if you are trying to keep costs down. I rebuilt mine and it was pretty easy.

-Max

 

Was that rebuild kit specific to the car, or are they generic Pep Boys specials? Avoiding the dealer is always a good thing IMO if possible.

jds

 

Did you ever solve this mystery? I'm having a vaguely similar problem.

 

I started noticing some weird pressure problems with my clutch, and one day clutch failed and stuck on the ground while I was driving to work. I found out that there was a huge leak with a flexible(rubber) clutch line on the firewall near the tranny tunnel, and it was a common problem after search.
I kinda fixed it wrapped around with high pressure hose with clamps had no problem, and recently clutch failed again and i noticed that rubber line was broke it half. There was no way to fix that line anymore, so I tried to look for this part(rubber flexible clutch line) online. No luck yet. Please tell me where I can buy this part? **picture would be appreciated since I wanna double check before I make a purchase.

Thank you

 

http://www.rx7store.net/product_p/clutchlinefd.htm