Spongy clutch after pressure bleeding

[JGood]

I pressure bled my clutch in my 87 325is after installing a new slave cylinder with ATE Super Blue, and it's spongy. It lets go near the floor, too, not near the top like my 325e. Is this air in the line or a clutch problem? It's a brand new Sachs clutch kit, slave cylinder, and fluid. No leaks or anything.

I didn't turn the slave cylinder upside down because there's not enough length in the rubber hose to do that, and the metal part of the line coming out the slave cylinder can't be turned in a way that won't hit anything. I have no idea how you guys are doing that.

I don't want to spend $30 on that stupid slave cylinder bleeding tool from bavauto if it's not even going to make a difference. Any ideas?

[Mike325]

I say that your clutch lines still have air in them. Give it another bleed to see.

I blead my new slave and master by hand with the slave installed in the normal position. You just need to do a lot of pumping and bleeding. Takes a little bit of time, but since you alredy have pressure built up, it should take less time for you.

[JGood]

I used a pressure bleeder. There's no air in the lines.

My question was can air stay trapped in the slave cylinder even after pressure bleeding or is this most likely another problem?

[nando]

I never had a problem with air in my clutch lines after pressure bleeding.. I did it completely dry too. I did let it bleed for quite a while, and I pumped the pedal several times to make sure. maybe try again and pump the clutch pedal while you bleed.

[backtrail69]

I used a vaccuum bleeder on my slave and it even took several sessions to get the air out.

[JGood]

A question: What the FUCK was the engineer who designed the slave cylinder thinking? I mean, COME ON!

I'll try pumping the clutch too next time.

[backtrail69]

No shit... I tried to manually bleed it and gave up...

[jlevie]

All that matters when bleeding the slave cylinder is that the piston is fully compressed and that the bleeder is the highest point. With the slave cylinder dismounted an clamped shut (read C-Clamp) that can be done with the limited mobility the soft line allows. That having been said, a Sach's clutch always feels soft to me and engages/disengages well down as compared to high performance clutches...

[rs4pro3]

I pressure bleed the clutch also, and usually always have to disconnect the bleeder, and pump the pedal by hand a few times, then re bleed to get all the air out.

[JGood]

Do I have to disconnect the pressure bleeder to pump the clutch pedal? I would think it would just pull more fluid in. What about just un-pressurizing it, and leaving the system attached?

I'd like to reinforce the fact that if I met the individual who designed the slave cylinder, I would like to punch him in the stomach.

[RobertK]

Pumping the pedal works for me every time no problems. Don't dis it until you give it a try.

[Ruffian]

Be careful that you're not raising the front of the car so high that the front of the slave cylinder becomes the high point, rather than the rear where the bleed channel is.

Did you say you pressure bled before installing the slave? if so, i'd install, then pump and bleed a few times.

*edit* the slave cylinder is an awesome piece of engineering. I love that the bleeder valve points down yet draws air from the top. that said, I love mechanical clutch rather than hydraulic.

[PiercedE30]

Easy way that I have found:
With slave cylinder not installed yet (hanging loosely), open bleed screw, depress slave cylinder with your hand, close bleed screw, repeat about 4 times while waiting about 30 seconds between each time to let the air float to the top. Then reinstall and press pedal a few times. Should be good to go.

This is the way we do it at the shop I work at. Works every time.

[nando]

I still don't get why you guys have such trouble with this. mine took maybe 20 minutes to bleed and it's worked great ever since. I guess I'm just lucky?

[backtrail69]

My biggest problem was that I had to front of my car jacked up too high so it started to suck air really easy. Once I figured that out all was well with a vac bleeder.