Strange Clutch Pedal Behaviour?

[Fat Audi 80]

Gents,

I have had some strange clutch pedal sypmtoms for a few weeks now. It started with the initial travel when depressing the clutch feeling a little lighter than normal. This also seems to result in a lower biting point than normal, (About half an inch to an inch from the floor).

The pedal also feels "slow" sometimes coming back up and IIRC I think it has stuck down once too.

This is especially noticeable when you first start up. However, after a few miles of a low biting point, it seems to get better and feel normal again with a higher biting point. (It stiill seems a little light as you first depress the clutch though)

I have had a feel around down there and can't feel any damage to the master cylinder rod or joint. Do I need to really get my head under there to have a proper look at the MC or is it something else?

Any ideas???

P.S. I had a new Clutch, Master Cylinder AND Slave about 4 years and 40,000 miles ago. Please tell me I don't need one of those again!!!

Cheers,

Steve

[GazzaG60]

take it fluid levels are good.

id hope not the master. maybe the slave.

sticky clutch bearing? siezed, worn slave rod?

[Fat Audi 80]

Sorry, yeah fluid level up the top, so don't suspect fluid leak as yet...

[Ross]

Had those symptomns on the Golf 3 times in the last 50k, seems to go through master cylinders at regular service intervals despite having clutch, slave & master cyl all replaced 20k ago

Aparrently something about the seal starting to leak, after some driving it goes normal and slowly gets worse until you end up unable to get the pedal to return and the bite point is at the floor...

[Fat Audi 80]

So I could have leaky seals in the master or slave then, or are you saying master?

That does sound feasible, as it does not seem to be mechanical. I will have to poke my head under there properly at some point and try and eliminate the master cylinder rod and joint from the list of possible problems.

I hate it when the car does not work properly, it takes all the enjoyment out of it...

Cheers,

Steve.

[Error404]

Have you tried bleeding the slave Steve? That'd be my first stop

[GazzaG60]

me too. its the cheapest and easiest try fix

[Fat Audi 80]

@ Alex & Gazza,

No, but once I have had a good look under the lower parcel shelf at the pedal mech and MC, that will be my next port of call...

Thanks.

[GazzaG60]

its a ***** design what more can i say.

do you have a pressure bleeder. its almost necessary. i use one from motive products.

[Fat Audi 80]

Yeah, I have a Gunson, so slightly less worried about that side of it... I have skinny arms too!

[mcandmar]

Sounds like a failing cyl, probably slave at a guess. I had the same on my avant for a few days, then it just went altogether with the pedal stuck to the floor. If i bled the system again it would work fine for half a dozen times, then stick to the floor again.

Where were the parts sourced last time it was changed? The one in my avant was only a year old when it failed, but was a cheap aftermarket item. The replacement i got from vagparts was a SACHS unit and much better quality. I also have an original ABY one and was a different make again, think it was Boge or something similar.

The big difference between them was the location of the bleed nipple, on the original parts the nipple extends out the end so you can actually get at it. The aftermarket unit had the nipple right above the hyd line so you had to remove the gear linkage to get at it.

[Ducky]

Sounds like my UR just before the master cylinder failed totally!

[mark_s2]

Bleeding the slave is a job that I don't envy skinny arms or not - we only remembered to bleed the clutch slave after we had dropped the engine in Ross' car and I was the lucky recipient of that job....

[johne]

Steve,

Don't see how it could be the slave cylinder. The slave either works or it doesn't and doesn't means it leaks and you loose fluid which you'd notice.

My vote goes on the silly flexi rubber joint in the master cylinder pushrod. Even if it feels straight, once you put it under pressure it'll give and bend. Unfortunatley you need to be upside down in the footwell to look up at the pushrod whilst you press the clutch pedal with a free arm - or willing assistant

John

[Fat Audi 80]

Thanks gents.

The Slave was a new OEM one that the AutoPool fitted 4 years. I do suspect the master cyinder and will get under there properly at the weekend if I can a decent look at it all....

Cheers,

Steve