DigitalSynthesis

Well... I finished fixing my heater core, put new brakes on, and am ready to change the oil, the spark plug wires, and the spark plugs... and I take it for a test drive... as I pull it back into the driveway from a successful spin around the block, the clutch pedal goes to the floor and stays there. . . uh oh... So I check the master clutch reservoir. No fluid. I fill it up, and bleed the system. I can get the system bled, but there is still not enough pressure in the system to release the clutch fork. I replaced the flexible hydraulic line b/c it was torn, but that didn't fix the problem.

It looks as though the slave cylinder (clutch release cylinder) is leaking, but when I took it apart, the only obvious defect was that the inside of the bore was slightly rusted. I don't think that would have cause spontaneous leak and loss of pressure in the clutch system, would it? I filled up the reservoir less than a month ago, but it's been fine up 'till now, when it won't hold pressure no matter what. I am going to buy a new slave (they aren't THAT expensive) and see if that solves the problem... but again, I didn't see anything obviously wrong.

The reason I don't suspect the master cylinder is that
A) there was no evidence of leakage around it and
B) it built up enough pressure to bleed the system and
C) it emptied the damn clutch reservoir already.

Hence I suspect the slave. I guess my reason for posting is two part... to share this anecdote, and to ask if I should be looking for something on the slave cylinder that might be more of a giveaway as to the cause of this sudden issue.

Peace....

madaz07

same thing happend to me i was driving home a about 12pm pushed the clutch in to select 4th took my foot of and it stayed there. so ive ordered a new slave and master cylinder to make sure as i just installed a new clutch a 4 puck brassy and the peddle is fookin heavy. 4 times as my last heavy duty!!!!!

DigitalSynthesis

Its fixed now... new Master and Slave cylinders... both appeared to have been leaking. After I took the master off I could see where it was leaking out the piston side... Anyway, drives great now. Nice firm clutch feel, smooth response.

Now, if I could just get that 2nd gear synchro to magically fix itself without a rebuild....

KNONFS

iTrader: (14)

How bad is it?

Try Red Line oil...........

But not the one everybody recommends (wich I've had bad experiences with )

Get the shock proof

DigitalSynthesis

Hmm.... its a quick grind into second IF I don't hold it a few seconds before fully pulling it into gear, but there is no difficulty shifting - nothing to indicate gear failure *yet*. Just as tho the synchro is worn enough to not quite synchronize but almost. And it only happens if I rev over 5k RPM, rarely if less than that.

Of course, I almost always *do* rev over 5k and then forget to be a bit patient on the shift. . . and the guy I bought this car from said the tranny was rebuilt w/in the past year. Yeah, right. I totally got gyped on the quality of the car, but I love it so much I almost don't mind. Except when major repair issues crop up that weren't supposed to.

GTUser

I just went thru the same problem this weekend but I was able to get home. When I checked the Clutch Fluid Master Cylinder Reservoir it was empty! I checked the Master Cylinder and Slave and found the hydraulic line bwtween the two was leaking at the end attached to the slave side.

I am wondering where did you go to get a new replacement line, Mazda dealer or an auto parts store?

The leak I found is not bad enough to keep me from driving my 89 NA as long as I keep an eye on the MC reservoir, but I do need to replace the hydraulic line.

Any help or advice you care to give will be greatly appreciated.

DigitalSynthesis

GTUser check your PMs...

AlmostRice

You should check all the bushing on the gearshift. If its sloppy and loose, it always seem like it does not go into gear correctly. Also using Redline gear oil helped a little too. BTW, i was not having any problems with my tranny. Goodluck

1BadassRevvin7

that happened to a friend of mine.....good luck

minclo

wow. strang twist of luck. This is happening to me right now. Everynow and then there is no pressure, but if i pump the clutch the pressure builds back up. i have clutch fluid still. Maybe change it? I don't see any leaks anywhere. Can someone give me hints as to what to check, what to look for?

DigitalSynthesis

Hehe... I'm actually doing a T-II swap now.. this was a very old thread that got resurrected recently. Thanks for all the feedback on it... I used RedLine MTL and it fixed it for the most part (unless I shift really fast at redline or really sloppy)... I have to say Redline Fluids rock!!!

chili

This seems like a common problem. Except my FD is now stuck in Canada!!!!
From what I've read here, it's either a Master or slave cylinder leak or hydrolic line leak. But.. can I just dump some fluid in the master and drive it home to the states? Will this work without bleeding and all that?

venomrx7

Pull down the carpet on the driver's side floor board, by the clutch pedal, and fell if the firewall is wet right beneath the rod going through the firewall into the clutch master cyl. If it is your rear seal is gone and you need a new cmc. I just had to do that a few days ago. If not there then check all of the line (rubber and metal) going from the MC to the slave cyl. if thats dry look around the slave cyl on top of the tranny and see if thats wet. All of these are easy to swap, just irritating when they go.

GTUser

Yes, you should not have any problems as long as you keep the clutch master cylinder filled with fluid. I drove my FC for a week, until I got the new hydraulic line from Mazdatrix, but then I had a small leak from a crack in the line.

GTUser

Yes, you should not have any problems as long as you keep the clutch master cylinder filled with fluid. I drove my FC for a week, until I got the new hydraulic line from Mazdatrix, but then I had a small leak from a crack in the line.

GTUser

If the MC reservoir got low enough to allow air into the hydraulic line then you will need to bleed the line to get the air out before you add additional fluid. You will not have a functional clutch if there is air in the line. Bleeding the line takes less than 15 minutes if you have an 8mm wrench or socket to loosen the bleed valve; an 18 inch length of plastic tubing, a glass container to hold the purged hydraulic fluid, and a friend to pump the pedal while you open and close the bleed valve.

bingoboy

this can be a master cylinder problem that is internal. you may not see fluid leaking OUT of it because there is none.

the problem is that while it is holding pressure in the line, fluid being held under pressure leaks back past the piston due to worn/broken seals. this will cause the lack of pressure in the line to leave your pedal stuck on the floor (since the pressure is what returns your pedal back to its lifted position). it will also not empty your fluid resevoir since the fluid is not leaking out of the system.

i have had this happen to both a brake and clutch master cylinder. often you can pump the pedal (after pulling it back up from the floor if it is that bad) to get it working again, but it will just go out again later. i didn't have the time to fix mine so i drove it like that for a good month before it finally went out completely and i had to drive to school and then home with no clutch (blek).

CBRFireman

I had the same thing happen. It was my master cylinder. The piston was full of pieces of the deteriating lines. I pulled the master cylinder apart and cleaned. Then replaced the fluid in the system. I have had no more problems to date.....good luck

chili

Thanks all....
Seems easy enough. I've been more and more courageous over time trying to fix the little things that arise. I just replaced the radiator last week myself and ta'da' it worked fine with no problems.
What really interests me though, is that a bunch of 20- something non-mechanics can build and fix a complicated piece of machinery like an FD, without problems....BUT A CERTIFIED MAZDA TECH CAN'T?????
I don't get it...
I made the mistake of taking my car to a dealer when I first bought it...they charged me $300 to tell me my engine was shot. That was 40 thousand miles ago! I plan on tracking that mechanic down in the near future and slapping his funny face with the dirty bleed line....after I REPLACE MY OWN MC.
This forum is the shiznit.

Also, if anyone wants to put together a how-to website for Rx7's, I have the domain 1rx.org..if anyone's interested.

venomrx7

Cool I've been waiting for someone to do something like that.