Searched but havent found answer to:

Last night the clutch on my 84 GS quit - wouldnt disengage. This morning I bled the system and got alot of air out, and kept getting air at the slave cylinder bleeder. I bled master cylinder at the connection to the hard line - no air. Then bled at the connection between the hard line and soft line - again no air. then again bled the slave and kept getting air (for about 5 master cylinder refills).

I then tried bleeding at the slave cylinder but only pushing the clutch pedal 1/2 way down - the air stopped coming. I bled about 4 refills this way and got no air at all.

So with the system clear of air, I again bled pushing the clutch pedal the whole way down - and again air started coming and wouldn't quit.

For kicks I bled at the slave cylinder pushing pedal 1/2 way again and the air purged and quit.

The slave and master cylinders are about 4 months old and are both new - not rebuilt. The soft line was replaced at the same time with a stainless braided one from mazdatrix. I can't find any leaks in the system and am too frustrated to work on it anymore tonight - I'm also out of fluid (2 bottles gone). I've also adjusted the clutch pedal height and rod clearance.
Help

Help

 

If you search you will find a few methods. The one that worked quickly for me was to physically remove (but keep hoses attached) the slave cylinder from the housing, raise it above the highest line connection on the firewall, then put a c-clamp across the whole unit blocking the piston from coming out. Be carefull not to overstress the clamp when pushing on the pedal and crack the bleeder just a bit. I used just enough pedal force to compress the fluid and force the air up through the bleeder.

A clear tube was connected to the bleeder, very quickly the air came out. I went through MUCH fluid until I tried this...

Be careful putting the slave back on - I found one really stripped set of threads in the bellhousing which made for a bad day.

Scott

 

Thanks Scott,
Thats how I bled the system when I installed the master and slave cylinders about 4 months ago I think I read it here then - it worked well. The system hasn't been apart since then and has worked fine until the other night. Believe me I searched this forum and two others with no luck.
Tomorrow morning the slave comes off for a closer inspection.

 

Silly question, you are keeping the pedal down when you open and close the bleeder nipple right? Sorry, just had to ask.

The only way air can get back into the system is if the bleeder isn't sealing, a fitting is leaking, one of the internal seals are bad or you didn't keep the reseviour full. If no leaks are showing anywhere then the master is leaking. Pull the carpet back under the dash, below the clutch and look for fluid.

 

Yep, closed bleeder first. No leaks found. Reseviour over half full all the time. Didnt get a chance to pull slave off today-top priority tomorrow after work.

 

Pulled the slave off today, it's dry as a bone. There are also no leaks coming from the master, or any of the lines. I'm stumped on this one, if there is air getting into the system, there should be fluid coming out somewhere right? Anyway, keep those ideas coming guys, I need help!

 

Take the master off and bench bleed it, then try again.

 

I'll give it a try.
thanks

 

Here's the story until tonight:
Bench bled the master cylinder 2 times - no change. (sorry trochoid)

Got pissed and took everything back out. Man I hate taking the slave cylinder off.
Dyed the brake fluid and put it all together on the bench. Wrapped all connections with clean white cotton cloth. Blocked the slave cylinder with a piece of dowel and a C-clamp so I could build pressure in the system. On the connection between the hard and soft line found a small leak. Must be sucking air there. Seems the fluid was running down the back side along the fire wall where you couldn't easily see it.
Looks like I've got to make a new hard line:

Who here has bent up their own hard line ? Are the flares just standard double flares like a brake line and what angle ? Going to check Mazda dealer for price and availability tomorrow but they'll probably want a small fortune.

 

Standard double flare like the brake lines. Nice job on the trouble shooting, very creative.

You might be able to find a line the right length made up, not sure if both ends will be correct though.

 

Thanks man,
I noticed when bleeding it I could see very tiny bubbles in the master cylinder (once in awhile). In hind site this should have probably tipped me off too. I thought they were just working their way out of the system at first.