Replaced Master Cylinder, Now No Clutch

[ccarlozz]

I replaced the master cylinder today. Bled all the brake lines and bled the clutch line last. I did this all with a Motiv Bleeder. A lot of dirty fluid came out of the clutch line, but once it was clear I closed the bleed line and finished up. Started the car and the clutch dropped to the floor. What am I doing wrong and how can I fix this?

The car is a 1987 325is.

Thanks.

[Dakotademon7]

I had a bitch of a time bleeding mine. I had to loosen the cap and keep pumping the clutch peddle with the system closed. I got some peddle and had to let it sit over night for the air to work its way up. A little more pumping and I had full peddle. I tried to bleed it the normal way but every time I got a little peddle and crack the bleeder open, I would get a dead peddle again.

[ELVA164]

Grab a friend. Have him/her crack the bleeder, then slowly depress the pedal until it reaches the floor. He/She then closes the bleeder, and you pull the pedal up. Repeat 4 or 5 times, checking fluid level in the master, then see what you have as far as pedal pressure.

Just as info, pumping the pedal repeatedly can worsen any issues with air in the lines by "dissolving" the bubbles and spreading them out. Not always, but it's possible. The method above removes that possibility.

Edit: Just thought of this too, but are you sure the bleeder is closing completely and the reservoir never went empty? A pedal that soft sounds like quite a bit of air is getting in.

[ccarlozz]

I had a bitch of a time bleeding mine. I had to loosen the cap and keep pumping the clutch peddle with the system closed. I got some peddle and had to let it sit over night for the air to work its way up. A little more pumping and I had full peddle. I tried to bleed it the normal way but every time I got a little peddle and crack the bleeder open, I would get a dead peddle again.

Thanks, I'll try that.

[ccarlozz]

Grab a friend. Have him/her crack the bleeder, then slowly depress the pedal until it reaches the floor. He/She then closes the bleeder, and you pull the pedal up. Repeat 4 or 5 times, checking fluid level in the master, then see what you have as far as pedal pressure.

Just as info, pumping the pedal repeatedly can worsen any issues with air in the lines by "dissolving" the bubbles and spreading them out. Not always, but it's possible. The method above removes that possibility.

Edit: Just thought of this too, but are you sure the bleeder is closing completely and the reservoir never went empty? A pedal that soft sounds like quite a bit of air is getting in.

So the pedal is on the floor, all the way pushed in. The reservoir was empty and disconnected from the system when I changed the master cylinder, but I never opened the clutch bleeder until I filled the system with brake fluid. I guess I need to figure out how to pressurize the system again.

[jlevie]

The clutch will self bleed if you pump the pedal 80 or more times.

[oldmann]

Bleed it backwards, from slave to reservoir. Motive Bleeder, pressurized?

Small tube on bleed screw, from Motiv, with pedal up, crack it open and push fluid up to reservoir, dont let res. overflow.

[ccarlozz]

The clutch will self bleed if you pump the pedal 80 or more times.

So open the bleed screw on the slave with a catch bottle for the brake fluid and pump the clutch by hand? This will bring my clutch pedal back to life?

[jlevie]

So open the bleed screw on the slave with a catch bottle for the brake fluid and pump the clutch by hand? This will bring my clutch pedal back to life?

Nope, just grab the pedal and pump it 80 or so times with the system otherwise normal. If that doesn't work, the master cylinder is bad.

[ccarlozz]

Just a quick update...I unscrewed the reservoir cap and pumped the clutch by hand like ten times and a few air bubbles escaped via the clutch line into the reservoir and the clutch returned to normal. I don't think there was much air in the system.

Thanks to everyone for the input. Appreciate it.

[Dakotademon7]

Just a quick update...I unscrewed the reservoir cap and pumped the clutch by hand like ten times and a few air bubbles escaped via the clutch line into the reservoir and the clutch returned to normal. I don't think there was much air in the system.

Thanks to everyone for the input. Appreciate it.

Glad you got it fixed.

[jaconway5]

Did you replace the slave too? I know only replacing one places added stress on the other old one and will cause it to fail at some point.


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