Replaced the master. Pressure’s holding up for couple of days now.
thanks

Replace both and be done with the problem. 

Good morning.

new master and slave arrived.
i pulled the rubber boot back and there’s a little fluid on the part that sticks inside the cylinder. Very little. from the outside, no visible leak. But the leak is probably enough to let air in. I suppose the system should be air tight.

replace slave and test before i replace the master.

thanks

did you peel back the rubber boot on the slave?  The piston can leak and the fluid sits on the outside of the piston. Careful if it's a leaker, that you don't get brake fluid on your paint.  Put some plastic on the clutch cover and firewall and some rags on top of the plastic.

My guess is the master passing fluid internally.

So I bled the system again couple days ago, shifted great.

Now, no pressure again.
Im still waiting for the parts, I ordered both master and slave, clevis and hose.

is there a test to pin point which one is faulty? Pressure test?
the way it is now, when i bleed it, it took only couple of depresses to get very good resistance. No leaks, that i can tell visually. I felt all the lines and no fluid weeping.

i disconnected the hard line and slave hose, depressed the pedal, flowed good. No obvious damage on the hose.

thanks again.

Slave is cheaper and easier also replace the hose while you are doing it and loosen the hose before you remove the slave.
If you replace the master first it usually blows out the slave in a short time from my experience.

Finally had the chance to check the car again.

there were no leaks on the slave cover or anywhere around it. Same for the master, no obvious leaks. 

I’ll replace the master first then test before replacing the slave.

thanks again for the input

Not just the success rate on re building Master cylinders as mentioned there is also the aggravation rate of removing them again if the kit fails.
Unless you are doing a concours 100 point build and wanting to keep everything original you are way ahead of the game with throwing the old master cylinder in the garbage and replacing it.

is it fixed now?  You said it drove beautifully after the last bleed.  Maybe it was just air in the system.  BUT, it could be a bad master passing the seals internally.

Can you find any fluid leaking out the end of either the Slave or the Master

Slave will leak out of the pushrod boot( or peel the boot back and look for any fluid)
 Master will leak down the clutch pedal.

 If the slave under the boot is dry its Most Likely a bad Master cyl where the fluid is passing the internal seals and its not not holding pressure.. 

Rebuild kits to me are 50/50 on being successful in the repair.

Hey there.
Car is 69 Austin MK II 1275
pre-verto clutch

the clutch pedal goes all the way through the floor.
i bled the system, works but only lasts less than a day. The following day, same issue. I checked the wear points, clevis pins and no obvious damage.
no visible leaks on either the master or slave. Hose looks clean.

last night i bled the system again. Master is full up to around the collar. No pressure on the pedal. Opened the slave valve, fluid flowed well, it took about two depresses, to get really good resistance on the pedal. Test drove, shifted beautifully.

before i change both, i would like to get some opinions on what else to check or if a rebuild kit would suffice.



thanks as always