Varying Clutch Engagement [Merged 1-9] bleeding air floor stuck grinding

[BoostInsideTSi]

Okay, folks, for some unknown reason, we're now getting three threads a week started about clutch malfunctions.
The usual cause is that the system hasn't been properly bled.

Have at it.

I put in a used, but in good condition master cylinder, to replace the one I had before with a broken rubber seal. I did not bleed any components, I simply took out the old one, and bolted the new one up. Then I proceeded to fill the reservoir with dot 3 brake fluid. Bubbles rose to the top of the reservoir, then I topped it off after the fluid ran down into the system. I looked at the clutch pedal and noticed it was still sitting on the floor. I tried pulling it up off the floor, but it only went up a few inches. Probably some adjusting that needs to be done with the rod is causing that. Anyway when I pull it up there is quite a bit of resistance, where when I let go the pedal just pulls right back to the floor. I've heard there is a vacuum going on, where with air in the system, it is just pulling that sucker right back. I tried pumping the crap out of the pedal with a friend opening the bleeder valve and I just shoot clutch fluid everywhere.. I Stop after about 50 pumps and put more fluid and keep going, but notice no improvement. Does anyone know what I need to do? Can anyone verify it is the air in the system causing my problem? Thank you,
Mike

 

[JusMX141]

Apparently that's where it's going to grab. The engagement point will vary depending on clutch disc / pressure plate wear, and disc material as well.

How much pedal free-play do you have when the pedal is all the way out?

 

[DeNoZZo]

what do you mean free play when its out? There is a harder to push section in the upper/middle of the travel if thats what you are talking about.

 

[JusMX141]

How far does the pedal move freely, with little or no resistance, at the very top of the travel before it feels as though it's compessing the fluid and moving the clutch?

 

[MichaelSuch]

I have the master adjusted properly or so I think and when I push the pedal down about 1/4 of the way it starts getting stiffer and engages. I push the clutch pedal down, put it into first and it grinds a little and easily let off the clutch and the tires will not move. I have the front end lifted up off the ground and when it's in gear the tires do not move unless I give it gas and even then they move maybe an inch. I didn't rebuild the tranny, I had a shop that rebuilds transmissions, differentials, starters, etc... rebuild the transmission. The clutch should be properly adjusted now to where it was at before but it seems like it's slipping like mad. I'm about to go out and do some more trial and error. And yes, the slave and master is working properly. The slave rod is pushing into the fork as it should.

 

[PIMking]

does this work on 1g's?

 

[DSM1G90]

Yep. works on 1G's since I saw the video as well, tried it on my '90 and it's all there...

 

[DeNoZZo]

How far does the pedal move freely, with little or no resistance, at the very top of the travel before it feels as though it's compessing the fluid and moving the clutch?

about 1/4 of the way

 

[brownfinger]

There is a little ball at the end of the pushrod where it fits into the master. There is a little cup in the piston, which this ball fits into. There needs to be SOME clearence between those two pieces. A tiny bit of lash. You need it so that you can wiggle the pedal with your fingers, and feel that absolute 'free-play', where the ball smacks around a little bit in the tiny cup. Just like a couple thousandths at the ball, or 1/8"-3/16" at the pedal. The only resistence you'll feel is between the pedal and it's own return spring. Think about that while you watch the video one more time. IDK if there is a 'stop' at the top of the pedal travel on a 2G. If there is, and you move it, you need to re-adjust the pushrod after.

 

[DeNoZZo]

if you mean free pedal travel like this guy than none
YouTube - Clutch Adjustment Part I

mine goes down fairly easily then softly gets a little harder to push. It's not like hitting something like the guy in the vid.

 

[Defiant]

mine goes down fairly easily then softly gets a little harder to push. It's not like hitting something like the guy in the vid.

Then you need to bleed your hydraulics a few more times.

 

[DeNoZZo]

Then you need to bleed your hydraulics a few more times.

I went out and re-adjusted it again, and now it engages perfectly. The problem is it wont go into any of the gears without grinding unless I pump the clutch pedal a few times. I checked the master for leaks and found none. And my slave seemed fine too. I just think it's funny because I have had to bleed the hydraulics a couple of times in the last month.

 

[JusMX141]

The problem is it wont go into any of the gears without grinding unless I pump the clutch pedal a few times. I checked the master for leaks and found none.

The master cylinder doesn't have to leak to be defective. It's allowing air to get into the system somehow.

 

[GRAVEDIGGER]

Make sure you bleed the system completely. It sounds like either the master cyl. is bad and sucking air, or it is not bled completely. I have the best luck with just opening the bleeder on the slave cyl. and just let it gravity bleed for a while, making sure it doesn't run out of fluid in the reservior.

 

[DeNoZZo]

Make sure you bleed the system completely. It sounds like either the master cyl. is bad and sucking air, or it is not bled completely. I have the best luck with just opening the bleeder on the slave cyl. and just let it gravity bleed for a while, making sure it doesn't run out of fluid in the reservior.

ok, thanks to all of you guys for helping

 

[MichaelSuch]

Well guys I bled it, bled it, and bled it some more until there were no air bubbles coming out the clear hose I had to the bleeder and adjusted master cylinder a little more to my liking. What the main problem was is that at first my drivers side wheel was locked up a little because the brakes were grabbing but my passengers side tire was moving just fine. Finally after 2 or 3 months of this thing torn apart for the motor and tranny rebuild I got to take it for a short drive. It rattles a little too much for my liking but boy I love it... Thanks for the help guys!

 

[DIMONDSTAR77]

finally got my parts, new question. does the master and slave cylinders need to be primed before starting to bleed system, or do leave everything dry?

 

[Kastigir]

finally got my parts, new question. does the master and slave cylinders need to be primed before starting to bleed system, or do leave everything dry?

Priming makes bleeding them easier when finally installed, but I don't believe they have to be primed. Someone can correct me if I'm wrong.

 

[Dsmj89]

Change both master and slave cylinders at the same time.

 

[JusMX141]

I've never primed a new clutch master cylinder when I installed it, and they've always worked flawlessly.

 

[DIMONDSTAR77]

thanks for the help guys, i think i'll prime just to save some time then. hope to have it moving this weekend.

 

[whitemike89pl]

Sometimes it happenes to my car, especially when is cold outside. My dad said that I must have a leak and the air got into my cylinder.
He just dumped a little bid of the clutch fluid out. Then he put more new fluid and everything works very well.

 

[Defiant]

http://www.dsmtuners.com/forums/dri...ch-killing-pump-up.html?highlight=clutch+Pump

 

[DeNoZZo]

http://www.dsmtuners.com/forums/dri...ch-killing-pump-up.html?highlight=clutch+Pump

Thanks!

I bleed the system and it works really good now, a little inconsistent, but it works now. I noticed the fluid in the reservoir was a little black. If I'm not mistaken, this means that the master is probably bad/going bad, correct? I plan on getting a new master/slave with ss lines as well in a few weeks as part of my maintenance anyways.

 

[DSM1G90]

Between the YouTube video from Jack's Transmissions and this link above, that pretty well explains all on doing these DSM clutch adjustments .. and maybe this pertains to all hydraulic operated clutches in other vehicles...

Excellent link by the way!

 

[ryan90]

was diagnosing noise under my car and was like okay.... looks take a close look at my slave cyl. and how it adjusts itself to the TOB. So i pressed it a couple times. Get in my car later and its like wtf. no clutch pressure.

so I bled it and bled it. I thought it was better but it engages at the floor and grinds.

Should this have happened?? It should have been just as if i did nothing as the whole system SHOULD have been sealed. Or did i just screw up the rod adjustment on the master cyl.??

the clutch was changed like 15-20k ago and to me the pedal also always felt soft. especially compared to my friends NT car.

I am going to try adjusting the rod, gravity bleeding, and checking for leaks.

This just does not seem right....something is leaking