Clutch pedal dropping

[Guest]

Some help please

i own an Audi A3 2lt tdi, 2006,

clutch pedal started to drop a few weeks ago,

i googled it, possible cause, master clutch cylinder, so i replaced last week,

no joy still the same problem,

so i changed the fluid, we put 1lt through the gear box,

still no joy,

one thing i will say, i am NOT loosing any fluid,

any help would be great

[cliffcoggin]

Mark.

Forgive me if I say you do not sound familiar with car repair, so please tell us how you bled air out of the system. Air is the most probable cause of your problem but it requires a particular technique to ensure its removal. It is not enough to simply open the bleed valve of the slave cylinder and pour fluid into the reservoir, which is what I assume you meant by "put 1 litre through the gearbox".

[Guest]

Hi clifford

yes you are right,

we filled the reservoir and just bleed through the slave cylinder,

i done it the way it was suggested to me,

whats the best way to bleed the system

[Guest]

7 hours ago, M60 said:

 

Edited January 9, 2023 by M60

[Magnet]

Hello Mark,

Sounds typical of clutch ‘release bearing’ (slave cylinder) issues.  Not at all uncommon unfortunately.

Kind regards,

Gareth. 

[cliffcoggin]

Mark.

You can buy special bleed tools to make the job a one man operation, but I have no experience of them. Alternatively if you can get the help of an assistant it will cost you nothing.

One man stays in the car to operate the clutch pedal; the other man goes under the car to open and close the bleed valve. It helps to have a plastic tube on the bleed nipple with its lower end in a glass jar. The sequence of operations is:

[1]The bleed valve is opened.

[2]The pedal is pushed hard to the floor and held there.

[3]The bleed valve is closed.

[4]The pedal is raised, and the reservoir topped up.

Repeat the above until no air bubbles are seen in the glass jar. It relies on good communication between both men with the pedal man being in command.

Having said all that, it is possible you have a faulty slave cylinder or a worn thrust bearing, but that can not now be diagnosed until you have bled all air out of the hydraulic system. You might have saved yourself some time and expense if you had asked the forum before changing the master cylinder. Google is a very fallible source of information, and needs to be treated with caution.

[Guest]

35 minutes ago, cliffcoggin said:

Mark.

You can buy special bleed tools to make the job a one man operation, but I have no experience of them. Alternatively if you can get the help of an assistant it will cost you nothing.

One man stays in the car to operate the clutch pedal; the other man goes under the car to open and close the bleed valve. It helps to have a plastic tube on the bleed nipple with its lower end in a glass jar. The sequence of operations is:

[1]The bleed valve is opened.

[2]The pedal is pushed hard to the floor and held there.

[3]The bleed valve is closed.

[4]The pedal is raised, and the reservoir topped up.

Repeat the above until no air bubbles are seen in the glass jar. It relies on good communication between both men with the pedal man being in command.

Having said all that, it is possible you have a faulty slave cylinder or a worn thrust bearing, but that can not now be diagnosed until you have bled all air out of the hydraulic system. You might have saved yourself some time and expense if you had asked the forum before changing the master cylinder. Google is a very fallible source of information, and needs to be treated with caution.

Thats the way me and my mate bleed the system

[cliffcoggin]

Well if you are certain all the air is out then the slave cylinder is the next most probable culprit.