Alfa Romeo Forum banner

1 - 20 of 25 Posts

·
Registered
Joined
·
83 Posts
Discussion Starter #1
Hi Folks,

My clutch had to be pumped to get into 1st or reverse gear. We checked the slave cylinder and no leaks evident. We drained the master cylinder and found traces of black residue on the bottom of the master cylinder cup. The fluid was dark brown.

We refilled the cup on a number of occasions but it keeps pumping through air and the clutch is very very light.

Could it be the master cylinder rubbers? If so, is it hard to remove? :depressed: I know the nut that secures the pipe to the cylinder appears tight and there is little room to put leverage on a spanner

PS the car has been standing a long time and has only completed 800 kilometres from new.

Any help would be appreciated.

Regards
Neil
 

·
Registered
Joined
·
1,708 Posts
The black gunge in the fluid is disintegrating seals so yes, its time for a new MC. The nut can be hard to get off.

I had a real struggle with mine last year and rounded it slightly in the process which makes it harder to re-tighten. I ended up cutting through the old cylinder with a Dremel, leaving part of it attached to the pipe. I could then grip the pipe nut with vise grip and twist the MC remnant to free it. A bit drastic but I was fed up with a simple job turning into a major one!

I have since invested in some better quality brake pipe spanners, the one I had was poor.

I didn't have any PlusGas with me at the time but I have subsequently used it on other similar applications and found it brilliant - much better than WD40. I would soak the connection with this and leave for an hour or two. That may free it up.

I think most people will say that if you are having to replace the MC and the slave has not been done recently it would be sensible to do both plus the flexi pipe.
I replaced the flexi pipe on mine after I had done the MC because I still had a heavy clutch. The new pipe made a huge difference.

Good luck.
 

·
Registered
Joined
·
83 Posts
Discussion Starter #3
The black gunge in the fluid is disintegrating seals so yes, its time for a new MC. The nut can be hard to get off.

I had a real struggle with mine last year and rounded it slightly in the process which makes it harder to re-tighten. I ended up cutting through the old cylinder with a Dremel, leaving part of it attached to the pipe. I could then grip the pipe nut with vise grip and twist the MC remnant to free it. A bit drastic but I was fed up with a simple job turning into a major one!

I have since invested in some better quality brake pipe spanners, the one I had was poor.

I didn't have any PlusGas with me at the time but I have subsequently used it on other similar applications and found it brilliant - much better than WD40. I would soak the connection with this and leave for an hour or two. That may free it up.

I think most people will say that if you are having to replace the MC and the slave has not been done recently it would be sensible to do both plus the flexi pipe.
I replaced the flexi pipe on mine after I had done the MC because I still had a heavy clutch. The new pipe made a huge difference.

Good luck.
Hi Thanks for that. I was hoping to just replace the rubber seals as the cylinder has hardly been used-do you think the whole mechanism needs replacing ?

Regards
Neil
 

·
Registered
Joined
·
3,991 Posts
Hi Thanks for that. I was hoping to just replace the rubber seals as the cylinder has hardly been used-do you think the whole mechanism needs replacing ?

Regards
Neil
I replaced just the rubber seals (with an original ATE repair kit, which had a little spring valve in it too).......but my cylinder bores were like new.

your S4 (only 800km....from new??) been laid up so long, you could argue the cylinder has hardly been used, but the hydraulic fluid will be almost water if it hasn't been changed for many years....you will only know when you dismantle it and see if the bores are good, or pitted with rust.

For the trouble (time) and the few extra quid, I'd just replace it and the slave with new (you say slave isn't leaking, but have you peeled back the rubber gaiter to see if it has oil in it?....in which case it is leaking)

whilst master is out, check the plunger lever has the required exact 134mm length, and notice this length is measured from the back of the hole....see post #2 here
Clutch Master Cyl. Problems - Alfa Romeo Bulletin Board & Forums

When it is all back and bled properly, then you should have 11-12mm movement for correct clutch engagement:
http://www.alfabb.com/bb/forums/6931674-post25.html

oh, and same with the brakes really, they will need thorough checking.........hydraulic fluid is hygroscopic, it absorbs water.

Dom
 

·
Registered
Joined
·
83 Posts
Discussion Starter #6
Hi Dom,

Just as a preliminary measure before I replace both cylinders, I replaced the master rubbers with a new Alfa rubber kit). The air is still getting in when I bleed. There is no oil in the slave rubber and the rubber hose looks good. Before I embark on replacing them both is there anything I should do about bleeding the system-is there a special way- other that pumping the pedal etc.?

Cheers
Neil
 

·
Registered
Joined
·
3,991 Posts
Neil,
are you 100% sure the clutch slave cylinder bleed nipple is at the top (12 oclock position) with the flexible hose at the bottom?
....the clutch slave can twist in its housing and if the bleed nipple is not at the top, you will not get all the air out. (sometimes people even turn it, as with the bleeder at the bottom it is easier to get a spanner onto!)
 

·
Registered
Joined
·
53 Posts
Quickest way:
Disconnect slave from the gearbox and let it dangle by the hose !
Let gravity do the work.
Open bleed nipple and wait till you see the fluid come out.
Close the nipple and refit.
 

·
Registered
Joined
·
83 Posts
Discussion Starter #10
Hi Folks,

Nearly there but some more help needed. After your advice(s) new seals were fitted to the master cylinder and then we rotated the slave cylinder and that was successful. However the clutch pedal has to be full to the floor ( and pumped) to engage reverse the res of the gear can be engaged but only when the clutch is hard to the floor.

On checking the manual the Clutch operating cylinder (slave) has a travel of 11 to 12 mm but on mine its 9mm or less. Would that affect the operation and if so how do you adjust it?

Again many thanks
Neil
 

·
Registered
Joined
·
3,991 Posts
...On checking the manual the Clutch operating cylinder (slave) has a travel of 11 to 12 mm but on mine its 9mm or less. Would that affect the operation and if so how do you adjust it?
Again many thanks
Neil
the hydraulic system is unadjustable; however if cylinders are good, no last pockets of air in the system, and the master cylinder actuating rod set at 134mm, then you should have the required 11-12 mm travel at the slave.

Another thing it could be is the flexible hose (you say it 'looks good', but if it is detoriating inside, it might still look good on the outside!)....when they get soft, they expand slightly when pushing the clutch pedal, in effect not pushing enough fluid to the slave where it belongs.
It should be replaced as a matter of fact if you do not know its age when doing any work on the clutch system....of course you'll have to bleed again.
 

·
Registered
Joined
·
83 Posts
Discussion Starter #12
Hi Dom and all those who offered advice but I not sure where to go now!. We followed all your advice and the clutch still requires to be hard to the floor to engage a gear and then for reverse and first it needs pumping. No air coming out BUT the slave is only functioning to a length of 9mm and not the 11 to 12mm as it should do. Not sure what to do next.

Cheers
Neil
 

·
Registered
Joined
·
3,991 Posts
Neil,
how certain are you the 134mm master cyl rod measurement was attained? If you did it when the master was on the car, it is very difficult to measure. If you did it before fitting the new master then OK you likely got it right.
I still guess there is air in there, or your adjuster rod was not set at 134mm.

what about experimenting a bit:)
try turning the adjuster rod at the master cylinder a few turns out, so extending it say a couple of mm (remembering exactlyhow many turns you have gone through - a blob of white paint on one flat of the big nut helps keep track! - so you can return it to exactly where it was, if necessary!), then test if clutch engagement is better. It is easy enough to do from the engine bay (a little silicone or WD lubrication of the rubber boot end where the big nut rubs against, helps)

only other thing I can think of is the clutch pivot arm, a weakpoint on the spider..........the weld can slowly twist and break.
Test for this is if the clutch pedal is hanging noticibly lower than the brake pedal (does yours?)
If it is hanging lower try pulling it up with your hand...if it moves the pivot is about to break....don't drive the car!
 

·
Registered
Joined
·
83 Posts
Discussion Starter #14
Hi Dom (and folks),

Many thanks for your useful suggestions as ever the problem seems to be solved I will keep an eye on it but the clutch is now much better.

I have one final (at this stage) question, that relates to a different matter and is so basic I hesitate to ask but here goes.

As the car has less than 1000 Kmts I have not been using it but when driving it to test the clutch I was unable to adjust the forward/rearward seat position. The handbook shows that both seats have a bar at the front which is lifted to unlock the seat on the rails. The passenger seat has one but the drivers does not. I thought the seat may have an electric adjuster but I cannot locate a switch.

Do you have any ideas please

Regards
Neil
 

·
Registered
Joined
·
1,708 Posts
An electric adjuster MIGHT have been fitted but it wouldn't have been standard. You should have the same bar as on the passenger seat.

Good news on the clutch, by the way. They should self-bleed to some extent so maybe just driving it around has helped?
 

·
Registered
Joined
·
3,991 Posts
Neil, your kilometers are going backwards...less than a 1000kms?
it was just over 2000 three years ago, when you bought it!!
only kidding, sure it is just a typo:)

as Nick says, the drivers seat has (well should have!) the identical adjuster seat bar under the front as your passenger seat has (like photo)
 

Attachments

·
Registered
Joined
·
83 Posts
Discussion Starter #17
Hi Folks, Many thanks for that, sorry about the mileage it has exactly 1584 klmts ( I was a 'back street' car salesman in a previous life!!!)

Thanks for the picture there isn't a bar on the drivers side why ever would that be?

Cheers
Neil
 

·
Registered
Joined
·
3,991 Posts
Neil,
I wonder if I could ask you a favour (and sorry if it is off topic here!):
As your car is basically factory new and it is a EU delivered S4 (photo shows your car, so darn clean!!), any chance you could get a good photograph of these 5 under bonnet decals for me (the 5th, the yellow electrical one with the 'flash' is standard)........no hurry, just if you happen to have the time.

my decals have all peeled off and gone awol.
I'd like to find the correct ones and the internet has many, but they are all different in small ways (especially the large black lubrication decal)

Like I say, only if you feel like it!

Cheers!
Dom
 

Attachments

·
Registered
Joined
·
83 Posts
Discussion Starter #20
Hi Folks,

Can anyone advise me if there is a special tool to remove the engine oil sump plug. It would take a hexagonal Allen key but the standard sizes are too small. The Alfa shop(s) tell me a replacement sump plug is size 8mm but mine is about 12mm (its difficult to be accurate).

Can anyone assist please.
Thanks
Neil
 
1 - 20 of 25 Posts
Top