Can’t bleed clutch master cylinder

[1-3-2-4]

On my ‘05 Lgt I have a new master Cylinder because the stock went out so I have a speed bleeder on the slave cylinder and what happens is when putting the stuff back I still have a very soft feeling clutch pedal. I took the slave off and made it the highest point and bled it again to no change.

 

Also I put a socket in the slave and held it with a C clamp in which then did I get a firm pedal. I’m at a lost now of why I still can’t get a firm pedal.

[lmdew]

With the slave bleed open, push the slave piston back in.  Close the bleed and pump it back up.  Fluid should be going down in the master.  

Move the master very slow and not to the end of the stroke on the push.

[1-3-2-4]

How I did it was I opened the bleed screw on the slave cylinder and it has a speed bleeder installed and I started.. however I'm not sure if I opened it too much too little and I still had some resistance and the pedal would not stay down, the other way it would stay down and I had to pull it up. I also tried bleeding with the slave higher then the clutch master cylinder.. Still no change.

I guess I will try it your way I did push in while the bleed screw was open but I did not close it between pushing it in.

[nvu]

Is it a push clutch transmission?  Could be cracked clutch fork if so.

[GeneralDisorder]

If the pedal is firm with the clamp on the slave then it's not your problem. 

05 LGT's had the weak turbo push-clutch fork. And the dual mass flywheel. You need the 08-14 WRX clutch, flywheel and upgraded 06+ fork. 

And before you end up with a blown turbo - pull all the banjo bolt filters and re-route all the turbo oil feed from the rear block main gallery. 

GD

Edited October 13, 2018 by GeneralDisorder

[idosubaru]

How do you know the stock MC failed?

What about the Slave cylinder and slave hose - those are commonly replaced together?  Could those be bad?

I’m not well versed on these like those guys are so ignore me mechanically here but I’ll point out that some people have had horrid times bleeding clutch fluid. I hate them.  I’ve spent stupid time bleeding, getting nowhere then the next day done in 3 minutes...I was already close to done?  Bubbles migrated somewhere convenient overnight? Who knows but challenging clutch bleeding wouldn’t be a first  

 

 

[GeneralDisorder]

There's a fool-proof process for the bleeding. It does take two people. We have it down to about 10 minutes. But that doesn't appear to be his problem. If it's stiff pedal when the slave is clamped then it's not a fluid problem.  Could be a weak spring behind the slave piston I suppose. But I've seen way too many of those first year LGT push clutches lose their fork......like all of them. And they have that damn dual mass flywheel. The fork was superseded to the 06+ version due to being extremely weak and prone to the legs folding off. 

[1-3-2-4]

Here is what I don’t get with a socket in the slave and clamped it’s hard.

now before I changed the CMC it would be soft when cold but when it’s warm it’s firm.

 

btw I’ve already rebuilt my motor so I’m good on no banjo bolts 

[GeneralDisorder]

Certainly could be a slave/hose failure. Get new NABCO slave and a new hose. 

[1-3-2-4]

Yeah I DO know the old one was acting up when I took the hard line off from the side and pumped nothing came out.... however when I fully took it off the car and pressed the rod in again brake fluid came out odd.. but I installed the new CMC I did not use the bleed screw on the front of it if that matters or not and I proceeded to bleed the slave the first night I spent about 2 1/2 hours and I still was not able to get a firm feel.

 

I'm going to get a new hose since it's the original the slave is almost about a year old

[1-3-2-4]

I was watching this video.. looks like I need to make sure I bench bleed..

 

 

[GeneralDisorder]

I have never had to do that on a Subaru clutch master. The hose will be wet if it's bad. Slave should be good if it's only a year old. Bleeding these can be a process. As a matter of necessity and through shear force of will we developed a process that works 100% in about 10 minutes with two guys. But once upon a time many moons ago I remember spending about 6 hour on one. Just about started throwing tools. And I NEVER throw tools. 

[1-3-2-4]

I completed it last night I replaced the hose with new and a new slave at first I still had issues but my wife came and she helped me out I was using a speed bleeder but I think what was happening was I opened the speed bleeder too much and air was getting in past the threads.. when I was pumping and about the time she came out to check on me the brake fluid was very foamy looking going up the tube into the bottle finally it was all clear about 5 min later and now the pedal feels better than before the CMC went out.