Hi after 6 months on the road the clutch started playing up so I bled the system and it was ok for a few weeks. I had replaced the slave cylinder during the clutch replacement saga.

So then I bled it again and it was okay for a few days and then needed doing again.

This time it only lasted a day or two. I am still driving the car because I haven't had the strength to do it again but it is a pain as sometimes the pedal doesn't return or when in traffic I have to coast in neutral while I pump it up to be able to put it into second.

I have checked each time and I am not losing fluid at all that I can see so any ideas how air can get into the system without losing fluid?

Sarah

if its air getting in then it can only be dodgy seals. If the slave cylinder was replaced, was the problem there also indicating the master cylinder to suffer the same problem. Is fluid leaking back into the cabin? Is the clutch pedal adjustments correct?
its only a clutch; cant be too much, can it?

Clutch master cylinder, sucks air back in past the single cup/seal when you let the clutch up.
Take it off the car, clean it out, if available put a new cup in. If not, reassemble and try it again. May just be some grit caught between the cup and master cylinder wall.

Thanks guys. Only a clutch? yep and only taken 2 years to get a new one fitted and running ok for six months.
I have noticed recently that when I leave the car overnight it seems ok the next morning for about 2k's then it starts getting spongy and sometimes the pedal won't return. So I slip it into neutral and pump like crazy and put it back into gear. it's ok for another few ks though spongy.
No there is no fluid dripping into the cabin. The slave cylinder was replaced because I thought there was something wrong with it but there wasn''t.

Thanks MadMax I will try your suggestions, that may very well be the problem. I hope so because another MC will be prohibively expensive.

And no I won't be getting an auto lol

I hope so because another MC will be prohibively expensive.

Right now on ebay average $120-$130 NEW with postage. Vee

well I have been running the car with a spongy clutch but yesterday it went again and this time bleeding the air has no effect. I still can't get it into gear. However now when the clutch pedal is depressed, and I am getting that way fast, there is a soft hissing noise. There is still no noticeable leak of fluid but I have no idea why something would hiss when I press the clutch pedal. It seems to be coming from the master cylinder but not sure.

Simple.
Push clutch in - fluid flows past cup back into the master cylinder.
Let clutch up - sucks air in past the pushrod instead of sucking fluid from the master cylinder.

No external leakage involved.

Replace/clean cup or replace clutch master cylinder.

My old Sigmas did this a few times.

Simple.
Push clutch in - fluid flows past cup back into the master cylinder.
Let clutch up - sucks air in past the pushrod instead of sucking fluid from the master cylinder.

No external leakage involved.

Replace/clean cup or replace clutch master cylinder.

My old Sigmas did this a few times.

Ok thanks. How do I know whether to replace cup only or or whole master cylinder? Kit is $70 and MC is $130, obviously I need to get away with the cheaper if I can but don't want to buy kit if I need whole thing.

how are you at fitting a clutch master cylinder your self
a pin / clip on pedal . and two nuts way up under the dash .
undo pipe in engine bay first

when it is out you can pull the thing apart (need circlip pliers)

then decide if think can be fixed cheaply or not

do you have a repair manual ?

how are you at fitting a clutch master cylinder your self
a pin / clip on pedal . and two nuts way up under the dash .
undo pipe in engine bay first

when it is out you can pull the thing apart (need circlip pliers)

then decide if think can be fixed cheaply or not

do you have a repair manual ?

Yes have been looking it up in the manual. It appears quite strait forward except I hate getting down under the steering wheel to get at the clutch pedal. My days of being a contortionist were non existent let alone being years over. My head and arms don't seem to fit under there no matter which way I twist and turn nor how loud I scream and curse.

learn to shift without the clutch?
Just gotta match the revs right and it'll slot straight in.
Save the clutch for red lights. :D

what about taking the drivers seat out

I used to recline the drivers seat and push it right back and lay on it awkwardly to do the job. Sometimes it is just easier to remove the seat and lay on the floor. Bit lumpy but some cars you just have to do it that way. Vee

Yeah taking the seat out is the first thing I did. But being 5'11 and 110kg and slightly claustrophobic it is hard for me to get my head under to see the dam clip to pull it out. Anyway I have done that, removed the MC and actually got the assembly out of the MC. However I can't disassemble the piston and spring. The manual says to lift the tab on retainer but I can't find a tab. Another manual calls it the spring thimble and the pic shows one tab. The one I have is plastic and there are 4 tabs that sit above the piston so lifting them isn't really possible.

Of course there was sediment in the cylinder and all the parts of the assembly so I need to take it apart to clean them in Metho properly. I think I may get away with simply cleaning them but until I get it apart I won't know for sure. So any ideas how to get it apart without stuffing it all up?

5'11", 110 kg?
Matches me perfectly, you must be my long lost twin sister! lol

Anyhow . . . .
Sounds like you have an aftermarket cylinder there, or one I haven't seen before. If the 4 plastic tabs point towards the piston, try pushing all 4 in at once so the piston can slide past them. Maybe a socket of the same diameter as the bore?
If you do get the piston out, clean it all up and look at the bore and cup for scoring. Doesn't take much of a groove worn in the cup for it to leak.

If that is not possible, fill the cylinder with metho and pump the piston to get some of the rubbish out.
You can tell how badly the cup on the piston leaks by filling it with metho, putting a finger over the outlet port and pushing on the piston.

Good luck.

Thanks MadMax, I think I will try it after lunch. It's just started persisting down with rain so I can't put it back yet anyway even after cleaning and if everything is ok.
Why is it that half hour jobs usually turn into 3 day marathons?

You have rain?
Me very jealous!
Send some to Adelaide!

Half an hour? Meh. A job takes as long as it takes. The end result is the important bit, not how long it takes to get there. (but I have spare cars . . . )

http://tscollect.com/piston.jpg

Sorry the pic is not too clear but as good as I can get. If you look closely you can see that the tabs actually sit above the rim of the piston and the spring is up tight against the plastic tab. I think I need to push all four or five tabs down somehow against the spring so they close. No idea how I am going to do that.

Now I'm with you . . .
You could pull the spring back and use some thin wire wrapped around all of the tabs to pull them together.

How grooved are the actual cups? If OK, just wash the whole thing in metho, and reassemble. Check the bore for scoring - a bright torch is best. If it is scored you will need a new master cylinder anyway, no point going further if it is scored.

Thanks I was thinking the same thing about the spring but I know I will stuff it.
There was a piece of rubber in the bottom of the reservoir. I thought it had broken off the rubber boot but that is intact except for a pin hole in the top which I assume is a breather hole because it looks as if it is meant to be there?
Will check for scoring first.

the repair manual isnt too helpfull on taking it apart is it
its a hard job to do

if the bore is not scored
you have a winner
replace the rubber bits
you have to hone the surface gently before fitting new cups
bleed refit

Nah I put it all back and bleed the system. Seemed ok until I started it and the clutch went soft and of course didn't work. Bled it again and same thing. It used to be ok when I first started it and then would sometimes go soft before it eventually went nothing. Now it is nothing as soon as I start the engine.

Does that mean a new MC or could it be something else?

the posts were out of sync




i

No I didn't. A clutch kit cost $70 and a new MC is $130. Didn't want to waste the $70 because as I said in an earlier post there is some scoring in the barrel.
The rubbers actually looked ok but then I never took it apart so who can tell.

Lots of gunk soaked off it though so maybe they are shot but it doesn't matter will get a new master cylinder now.

Well I put a new Master Cylinder on. During the process I dropped one of the nuts and it fell into that hole in the metal bar down below. Don't know what that is but the nut is gone forever.

The new MC works great and was nice and tight, but now it seems to have slackened off. Is this normal?

When the slave cylinder was replaced, was it new or second hand? how much has the master slackened off, 1/4 inch peddle free play is normal

When the slave cylinder was replaced, was it new or second hand? how much has the master slackened off, 1/4 inch peddle free play is normal
I didn't replace the slave cylinder I replaced the Master Cylinder and it was new. It isn't really that there is more free play just that it is easier to push the pedal down.

well, since the master is replaced, there isnt really much else left, i think from memory there is a small bleed down spring, it looks like a little cone looking spring, i dont know if its in the slave cylinder, obviously you have a new master now so no need to check that out anymore. but if that spring is in the slave and is back to front it can cause a slow bleed down in the clutch pedal.