Hydraulic issues master cylinder T5
 

HI everyone, was curious to hear some advice before i go ahead and try to call Martin from Monster Miata...

I'm in the middle of my build, I installed the clutch some time ago.. connected everything, blead everything, tested, all seemed great.

Until the other day when i was going for an imaginary drive pressing the clutch and shifting gears, and i noticed hitting the clutch several times, got stuck. The clutch fork was pushed in all the way and stuck... opened the bleeder screw on the slave, clutch fork imidiately retracts as the fluid pisses out...

after more testing, I realised you can slowly press the clutch and never have an issue, but if you press it quick and hard, 2-3 times, the fluid does not return, the clutch fork stays fully pushed until i open a bleeder somewhere.

last couple tests, I disconnected the clutch line, right at the master cylinder and the fork retracts, the fluid pisses out right at master cylinder connection... leading me to beleive there's an issue with the monster miata master cylinder....

Thoughts???


Thanks guy.

Gabe.

Look up some master cylinder diagrams, you will see a "relief port" internal to the master cylinder. That port has to be open when the pedal is all the way up. If not, it will cause the "lock up" condition you describe. It's basically an adjustment issue at the master cylinder pushrod to get it right. If I recall, there has to be some free play at the rod, because the port is open by design when the master piston is all the way back.

Mike

Mike, thanks for that tip. It's funny you say this, because I know there's definatly some preload on the cylinder when the peddle is not pressed, I distincly remember it when i installed, and reinstalled that master cylinder...

I will check out some diagram, then look into adjusting this, and report back.

you learn something new everyday!

Mike, you were absolutely correct... I actually had to cut the pushrod by about 1/4 inch since when I backed it as far as possible it was still pushing the CMC's piston..

at first i adjusted it just tight.. and the problem persisted, i loosened it very slightly as the pressure had stayed stuck, and immediately heard the clutch release itself, and heard the fluid squirt back into the CMC. I was amazed at how much difference that last little bit made...

Mike - thanks again!

Gabe.