Clutch will not build pressure

[Menting311]

My son bought a 2014 Audi A4 manual recently. Not sure if it had a bad clutch when we got it or if there was something going on with the clutch that caused him to burn it out quickly.

Either way, we pulled the transmission out. Replaced the pressure plate, clutch, and flywheel.

Now with everything assembled the clutch just snaps right to the floor, like the spring pulls it down. We attempted bleeding the slave cylinder, I had him push down the clutch. Then I opened the bleeder and a small amount of air comes out... Did that for about 15 minutes...

Still there is no pressure building on the clutch pedal.

I disconnected the line that goes to the transmission and had him pump the clutch and no liquid is coming out of that line. I can tell there is a small amount of air going in and out when he pumps the clutch but I expect fluid to be pushing out of that line, right?

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[StuckAntichris]

You may have better luck with responses in the main forum but I will try to help here. Could be a bad master cylinder at the pedal itself. But before you go through taking that out, double check that you don't have a clogged feeder hose from the brake master to the clutch master. Once double check that, ensure you have enough brake fluid in the reservoir so that it actually flows down to the master cylinder. Once you have verified those two things try plugging the end of the line with your finger while you pull the clutch pedal back up. Just to make sure you are passing fluid. Then you can hook everything up and bleed normally. If you still can't get pressure, it's probably the master cylinder.

Hope that helps

[Menting311]

@StuckAntichris yeah, I have plenty of brake fluid in there. I think I'll start by checking the line from the master down to the clutch.

How does the fluid get from the brake reservoir into the brake master, and then down to the clutch master cylinder? Is it just gravity fed because the reservoir is higher? Would you have to first run the vehicle to build brick pressure in the master cylinder for the brakes by the firewall?

I guess I'm trying to understand the path of the fluid between the reservoir down to the clutch. If you could help.

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[19birel]

I would also guess clutch master as well, though as Chris mentioned checked that feeder tube between the brake master & clutch master first.

EDIT: The link here has a nice diagram of the clutch hydraulics which you may find helpful Click Here

[StuckAntichris]

In @19Birel's diagram its #8 and yeah it's just gravity feed into the clutch master. No need to pump the brakes or anything. Could just be clogged up or the master is bad but worth checking just in case it's something easy vs doing the master.

[Menting311]

Well I feel dumb but I figured out the issue...it was low on brake fluid. However, I thought I would post this here in case anyone else had the issue.

The thing that confused me was looking at the side of the container I could see it almost at the max line, and looking inside it appeared pretty full. However, there must be a baffle or separator in the reservoir that separates the clutch side. Because when I removed the hose to the master nothing came out. Then I poured more brake fluid in and it started filling up the clutch side and I was able to bleed the clutch quickly after that.

[StuckAntichris]

Glad you got it sorted out and that it was a simple fix! Thanks for replying with the fix!