Further Clutch Woes

[Victa]

So... after having my clutch replaced with the Exedy HD variety the missus complained that it was a bit hard to work...

So I performed the "Clutch Adjustment" mod... this improved things, but not much... I noticed that when adjusted in too far the pedal would "stick" abut 3/4 of the way up before popping up the last bit... thought this was just one of those odd things and adjusted the pedal to the point above where this happens (2.5 turns in from std)... I also noticed occasional slow return of the pedal at the upper end of the movement, which got a little worse over time.

Next up I bled the clutch hydraulics, this made a HUGE difference, clutch becme much more friendly and all pedal slowness or stickiness dissapeared! There was one thing I thought odd... with the bleeder nipple open the pedal pulled itself down to the floor when pushed down a little. Once pulled back up to the "inflection" point it would pop back up under spring pressure.

However over the next few weeks the pedal stickiness returned, getting to the point of being annoying, so I bled the clutch again, which made no difference this time... Then I noticed that I had used DOT4 brake fluid (both times), instead of DOT3, but did not think this would matter too much.

This has gotten worse by the day, and now I have a very frustrating clutch to operate... if it has not been used for a bit (60 seconds or so) the first push on the pedal feels very soggy, the clutch only half disengages, and the pedal sticks 1/4 to 1/2 way back up... Putting a toe under the pedal allows it to be pulled up, and as long as it is being used continuously it seems to work just fine... however as soon as it goes unused for a minute or so...

The clutch can be "pumped" up by bouncing on the pedal lightly before attempting to use it, making me think that it was still a fluid issue due to the incorrect fluid I had used so this afternoon I obtained some DOT3 and bled the whole system again... with little difference...

The problem seems to be much worse when hot than cold, and I am not losing any brake fluid... The slave also seems to retract correctly when the foot is taken off the clutch, even when the pedal does not return properly.

Now thinking that this must be either the pedal assembly (unlikely?) or the master cylinder... sigh...

Anyone got any ideas on this one?

Chris.

[Spudspec]

ooooooooh intermittent type faults... Could be heat, causing the fluid to doil, the only difference a dot3- dot4 should make is performance at temperature, but stick to what the book says, as it may attack some seals. If you are positive it is not losing fluid, then check for any high spots that air could get trapped, I have found on some cars even after bleeding several times, there is still air stuck.. OR, maybe there is some crap causig the slave cylinder to stick, if it is a bit older and been worked hard it can wear internally and caus the piston to cock over and sstick.. I would go to a brake place and see what they charge to o/h the master and slave, or if they have exchange units.. Generally the rebuilt onse are sleeved with a nice stainless sleeve to eliminate wear.
otherwise maybe its just old seals.. OR, it could be even worse and be the Clutch pressure plate where the fingers meet the throwout bearing.. might have a dickie plate.. so many things, hard to diagnose without tryingit in person.. but hope these ideas help.

[MPS2NV]

If you have attempted to adjust the pedal height I have seen some spring assemblies over lock past a normal operating range which will pull your pedal down, if that were the case it would also make bleeding your clutch a pain as you wouldn't be using the full travel of the master cylinder, same applies if your thrust bearing is now to far away from its original position as you have run out of travel on the slave cylinder. might be worth a trip back to shop?

I have never had a bleeding issue with my 6 but a mates gen2 was a mole once it had air in it! lol

[yodo]

I never looked at the clutch pedal in the mps6, as ive never had issues.
Bleeding the hydraulic system has no bearing on the return of the pedal.
Above the push rod which you adjusted the freeplay should be a return spring.
Most cars have the ability to adjust the return tension. In doing so, you adversely increase the force required to disengage the clutch.

If you get no joy from that, than its most likely a worn/broken plastic bush on the top of pedal where it pivots from.
The bush is fitted in between two metal pieces to make the swing action smoother.

I'll have a look at my pedal in the afternoon.

[yodo]

I had a good look at the pedal this morning.
It appears to have 2 return springs, one at the top which is the main return spring and one in the elbow of the pedal where it pivots from.
I'd be checking your freeplay adjustment firstly. If theres too much freeplay, you'll have a sloppy return in the freeplay portion of the swinging arc.
Secondly, make sure all the plastic bushes are intact. There appears (hard to see) to be x2 on the top return spring and x2 on the pivot rod.
Lastly, depress/release the pedal and make sure neither of the x2 springs bind up or move in and awkward fashion.

[Victa]

After completely losing clutch operation on the way home this afternoon (thankfully just around the corner from home)... I have found the problem...

My clutch line has exploded...

Thankfully should be an easy and cheap fix... that is as long as the borked geachanged when the clutch line let go did not damage anything...

Sigh

Chris.

[Victa]

Well, I took a gamble today... I ordered a part from MPSG...

Adam(?) assured me that the part (Corksport braided clutch line) was in stock and would be in express post within the hour. Paid by credit card over the phone.

So, by tomorrow afternoon I should have a shiney new clutch line to install...

Chris.

[Victa]

Woots! The clutch line has arrived!

Approximately 26 hours from ordering to delivery, now that is service...

Hopefully an easy install once I get home this arvo...

Chris.

[Yeldarb]

Kudos to MPSG!

[Victa]

Clutch line in and fluid bled...

Problem solved... much better feel than even before this started happening.

Examination of the old line show a small split in the inner lining, and the outer lining peeled away from the inner like a banana skin, with a big split in it. I guess the fluid has been leaking into the outer and "inflating" it like a baloon... until it popped...

Chris.