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Discussion Starter · #21 ·
When you have vacuum on the system the pedal will not function properly. Trying to pull the pedal up while under vacuum may have just pulled air through the slave, and given you the dead pedal.

The idea is to get old air and old fluid out so it can be replaced by fresh fluid in the reservoir.

Apply up to 30mmHg vacuum, with a reservoir of new fluid. When the pedal is all the way down and no more fluid comes out, remove the mity vac hose and that will "suck" new fluid into the master.


Repeat a few times.


Only pull the pedal back up, and check fluid levels once you have removed the mity vac.


Look for leaks on the lines or slave. Check pedal function.


Report back.

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I read not to go over 15mmhg or you could start sucking in air through the slave cyl seal. But I’ll try more! Hope it works!

My problem is I draw a tiny bit of old fluid from the line at the bottom of the reservoir and fresh fluid fills back in the line but after that I can’t get any more dirty fluid. I just keep sucking the fresh fluid in the line over and over, No matter how much I vacuum (I’ll go try more vacuum up to 30mmhg).

Even when I pull the pedal up the master cyl doesn’t fill with any fluid, that’s why I think there must be a clog on the inlet or something.

I bought a new OEM master cylinder I guess just in case I need to replace.


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I read not to go over 15mmhg or you could start sucking in air through the slave cyl seal. But I’ll try more! Hope it works!

My problem is I draw a tiny bit of old fluid from the line at the bottom of the reservoir and fresh fluid fills back in the line but after that I can’t get any more dirty fluid. I just keep sucking the fresh fluid in the line over and over, No matter how much I vacuum (I’ll go try more vacuum up to 30mmhg).

Even when I pull the pedal up the master cyl doesn’t fill with any fluid, that’s why I think there must be a clog on the inlet or something.

I bought a new OEM master cylinder I guess just in case I need to replace.


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I have gone up to 30mmHg - but your additional details make me think that is not the issue. 30mmHg is around 0.58 psi by the way. I don't think you will hurt anything - it's because the slave cylinder seal can pull in easier than it pushes out - but potentially you could dislodge the slave seal I suppose. I just don't think it's realistic after having been there myself.

It sounds like the reservoir hose is not fully seated onto the Master or the slave hose is not fully seated into the Master. I think the hose ends are valved where they have to be fully seated to be open. Even if the Master is damaged, I'd still expect you to be able to pull fluid through it (or have it leak).

Perhaps there's sludge or gunk in the Master - using a higher vacuum pressure might just pull that loose, but you might have enough corrosion where it will leak and you'll be replacing it soon.

I'd say remove and reattach the hydraulic lines to the Master (it's a bear to get to them) to make sure they are mated properly (you have to seat them firmly to create a connection) - and then see if you can bleed more. If not, then you're replacing the master anyway.

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Discussion Starter · #23 ·
I have gone up to 30mmHg - but your additional details make me think that is not the issue. 30mmHg is around 0.58 psi by the way. I don't think you will hurt anything - it's because the slave cylinder seal can pull in easier than it pushes out - but potentially you could dislodge the slave seal I suppose. I just don't think it's realistic after having been there myself.

It sounds like the reservoir hose is not fully seated onto the Master or the slave hose is not fully seated into the Master. I think the hose ends are valved where they have to be fully seated to be open. Even if the Master is damaged, I'd still expect you to be able to pull fluid through it (or have it leak).

Perhaps there's sludge or gunk in the Master - using a higher vacuum pressure might just pull that loose, but you might have enough corrosion where it will leak and you'll be replacing it soon.

I'd say remove and reattach the hydraulic lines to the Master (it's a bear to get to them) to make sure they are mated properly (you have to seat them firmly to create a connection) - and then see if you can bleed more. If not, then you're replacing the master anyway.

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The higher vacuum didn't really help any more. I think something is clogged or like you said maybe some hose got kinked? but from the gradual symptoms that went away initially with some fluid change leads me to believe it is gunk clogging something.
Waiting on my replacement master cyl. It was only like $120 so if its difficult to get to I might as well just replace rather than have to do it twice.

What makes it such a pain?

The biggest pain right now will be getting it in the garage to work on it when I cant fuckin drive it.
 

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DIY Transmission removal and clutch swap. And Master...

You've already seen my thread on this, but the third post in my Clutch DIY post covers it. And I had forgotten this until looking at my thread again - but apparently I had a defective (leaking) reservoir hose when I replaced my Master Cylinder. So yeah... always something!

I hope the new Master solves your problem!
 

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Discussion Starter · #25 ·
DIY Transmission removal and clutch swap. And Master...

You've already seen my thread on this, but the third post in my Clutch DIY post covers it. And I had forgotten this until looking at my thread again - but apparently I had a defective (leaking) reservoir hose when I replaced my Master Cylinder. So yeah... always something!

I hope the new Master solves your problem!
Ah yes I saw that thread I didn't remember that you went into detail on the master cyl. Ok it doesn't look too terrible. I don't have to drop the transmission or anything like the stupid slave cyl.

Thank you so much for making these super detailed writeups with pictures. I hope mine goes smoothly and actually fixes the issue and I don't have a problem with the slave... If its the slave I might have to see about some "Jewish Lightning" hitting the car. (Yes I know that is horribly offensive lol).
 
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You have a master cylinder, a slave, and two hydraulic lines. Amazing how complicated such a simple system can be! Lol

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Discussion Starter · #27 ·
You have a master cylinder, a slave, and two hydraulic lines. Amazing how complicated such a simple system can be! Lol

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For real!
I have worked on so many cars and my manual Subarus and Hondas, bmw and Audi even all had super simple clutch hydraulics lol.

I don’t know why they didn’t put at least a remote bleed line on the slave when they went with the hydraulic TOB.


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Discussion Starter · #28 ·
I got my new Master cyl and it comes pre filled with the resevoir and everything hooked up which is nice.

@random84 when I take the old one out would there be a way to use my mityvac to bleed the slave from the connection that goes to the master cyl?

I dont know if that makes sense but I just kinda would like to flush/bleed the slave first before putting the new master on there in case there is a bunch of gunk in the slave that will fuck up my new master.

Thanks!
 

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I got my new Master cyl and it comes pre filled with the resevoir and everything hooked up which is nice.

@random84 when I take the old one out would there be a way to use my mityvac to bleed the slave from the connection that goes to the master cyl?

I dont know if that makes sense but I just kinda would like to flush/bleed the slave first before putting the new master on there in case there is a bunch of gunk in the slave that will fuck up my new master.

Thanks!
No, you just pull air into the system and mix it with any residual gunk. There's nothing to give except the seal, so leave it be.

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Discussion Starter · #30 ·
No, you just pull air into the system and mix it with any residual gunk. There's nothing to give except the seal, so leave it be.

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Ok yeah that makes sense. Bummer. Ill just have to pump the shit out of the pedal once it starts (hopefully) working again.
 

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I still vividly remember swapping the clutch master. Such a bitch to get it rotated into place. It’d take 5 figures to make me do one again!

You need a pulley setup to get it in the garage with that hill dude!
 

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Discussion Starter · #32 ·
I still vividly remember swapping the clutch master. Such a bitch to get it rotated into place. It’d take 5 figures to make me do one again!

You need a pulley setup to get it in the garage with that hill dude!
In other cars I would try to ride the starter lol.
Maybe I’ll just put some foam noodles on the front of the LX and push it up lool


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