Variable Clutch

joshuah

Forum Member
Joined
May 3, 2009
Messages
12
Location
Kuranda, QLD, Australia.
Hi,

I'm hoping some one can help me out a little here. I recently had my dual-mass flywheel and clutch replaced on my MY02 Outback.

I opted for the conversion solid single-piece flywheel and clutch kit. Now, though, my clutch free play varies from day to day.

When it is cold, freeplay is correct. After i have driven home up the range, for example, when i next go to depress the clutch pedal, freeplay is about 3 inches!

When the clutch is in this state, and the engine put under some load, a noise (a dull growl) can be heard from the clutch bell-housing area. Also, engine braking in 3rd mostly, becomes very jerky. As does acceleration

The following morning, the first clutch depress is dodgy, but subsequent ones are normal again. The problem occurs moreso when the day is hot.

I took the car back to the garage where i had the clutch done. They re-bled the hydraulics twice and the car seems fine for about a week until it starts to happen again. I thought it must be a hydraulic problem too, but the feedback I am getting from the drivetrain sorta leads me to believe that something else may be wrong. What do you think?
 
I have to agree with nipper, sounds like a hydraulic issue. Cold, thicker fluid, staying where it needs to be. Fluid warms up and thins out, bypassing worn seals. Could be either master or slave cylinder. I went through this about a year ago with my Toyota, changing both made a world of difference.

BUT...big but, one other thing I had to replace and worth checking as well, there is an 'isolator' hose in the clutch line of my Yota. This is a piece of flexible hose between, where the hard line runs from the master cylinder along the fire wall, to where the other hard line runs up from the slave cylinder to isolate the difference of vibration between the body and transmission. If it gets old and worn out, when cold it won't expand too much, then when it warms up it will expand more allowing more pedal travel, so check it out as well and probably replace it too.

Oh, and Howdy and :welcome: to the forum!!!:)
 
Maybe just bleed it first
 
Thanks for the help. Unfortunately it's a public holiday, so everthing here is shut.

But does anyone else think it suspicious, that these problems all started with the install of the new clutch? Could the mechanic have damaged anything? I agree that it looks like a hydraulic problem, but i am not convinced because of this coincidence.

I have found no leaks anywhere, including under the floor mats. The reservoir is still full and the clutch works fine unless it is hot.

Theories? Bad luck?:)
 
No its not coincidental, its the same reason that high mileage brake master cylinders fail. The internal cups are tired. Also from repeated strokes over the life of the cylinders a little ridge and dirt tend to accumulate internally. Under normal use you never storke the cylinder far enough to wander over this ridge. When you go to bleed the system, as in a clutch service, you can wander past this ridge and tear the cups.



You wont find any leaks as the problem is the cups. As the engine warms up, the cups get warm and soft. This can allow fluid to bypass the cups, and never really leak out of the system. When they bypass the cups, you loose pressure.

It's just wear and tear.

nipper
 
Righto,

Well, took the soob to the mechanic and after a bit of discussion, decided to check the hydraulics. The master was apparently squeeky clean, but the slave had a little grit in it. The Slave was cleaned and put back in. The car seems to work as she used to, but i'll let you know in a week or so to make sure it's better for sure...

Thanks for the input.
 
I have had similar problems after fitting new clutch. My mechanic read your posts and feels the Master Cylinder is at fault. Has ordered a replacement Subaru one from Sydney.

Did replacement of the slave cylinder fix the problem?
 
Variable Sticky Clutch

When I ordered the master cylinder the Suburu Dealer told me that it sounded like a problem that has been identified as Slave Cylinder problems in hot areas Since I am in South Australia at present I didn't think it would be the case. They had the slave cylinder in stock and the master cylinder would have to come from Sydney.

I took a punt and purchased the slave cylinder which came with hose and a new heavier spring for the clutch pedal. They have been installed and everything is working fine. Even the First Mate is happy:lol::lol:

Can't help wondering if maybe fitting a new spring would have solved the problem.

We are leaving for the Alice and Red Centre towing Corimal Camper in two weeks so hope all will be well.
 
Well, it's been a couple months since the problem arose and both the master and slave had been pulled apart. The last visit seemed to have fixed the problem as there was some rubbish in it (one of the cylinders). The other day, though, driving through the busy streets of Cairns, the clutch free play increased significantly and rapidly too. Sick of the whole thing, while at the lights I pumped the clutch like a mad-man and guess what?! It righted itself! That was about 3 weeks ago, so we'll see if it plays up again.

Now, i'm not sure what's going on in there, but it seemed to me like something reset mechanically...
In any case, clutch ok for now.
 
Well, it's been a while and I thought I'd update you all.

I have had the slave remachined, the master remachined, installed a new clutch but the flexible hose was deemed ok. Guess what?! My clutch pedal free play still varies! Pretty cranky. It doesn't happen as often, but it's still there. This morning I was down to half a pedal before the pedal gave any pressure.
That just leaves either the hose or, maybe, a little left field, could the flywheel be moving in and out of the engine/crank???

Either way it's a sad state of affairs...
 
nipper said:
If your flyhweel was moving your engine would be all over the raod in itsy bitsy parts.
Click to expand...

Yeah I've heard of flywheels exiting out vertically from the car! I'd like to see some photos of it happen...

The other thing it maybe, and this is a left field thought, is the clutch pressure plate is broken, I don't know how this effects its performance or pedal pressure but its a thought.

All the best with sorting it out!

Cheers

Bennie
 
Solved!

Fixed.
What was happening was that the solid interaction between the engine and drivetrain was transmitting forces back through the forks to the clutch slave, gradually pushing it back into the cylinder. This effectively reduced the amount of clutch available, creating all the free play. The mechanics just installed a stiff spring inside the slave to stop it from moving up the barrel. 48 Hrs later, clutch is still great.

These problems stemmed from a new clutch installation, going from the cusioning of a dual mass flywheel to the instant energy transfer on a solid flywheel. I would recommend seriously reconsidering going the conversion given my problems and reduced smooth coasting abilities, despite the extra costs. I'm not sure if this is related to the "throttle issues" thread in 'General Troubleshooting' pages...

My thoughts. Thanks for the input. I hope this helps others!:)
 
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