911vet

Due to bad advice from the Bentley Manual (which I will no longer accept as divine wisdom from the panultimate authority of the universe) and a local Porsche mechanic (whom I will no longer dignify by calling a Porsche mechanic)...

... I did an Oh SH*T today.

I had my brother pump the clutch pedal while bleeding the slave cylinder. I pulled in a huge amount of air - to the point the clutch pedal would fall to the floor with the slightest pressure and stay there.

In addition to pumping the pedal, I also managed to let the reservoir get too low on fluid so air got sucked in there as well as at the slave.

I refilled the reservoir and the Motive Pressure Bleeder pump. Then, without touching the clutch pedal, drained over 1 qrt of fluid through the slave. A BUNCH of air came out. I drained until there was no air and continued to drain quite a bit longer.

Clutch pedal now feels fine. Maybe a little easier (softer) to push in than I remember it being. But drives and shifts fine.

Do I need to try to bleed the master cylinder? There's no bleeder on it, so do I somehow open a line and try to bleed it?

Is it possible that I could have cleared the air from the upper cylinder and lines and forced it out through the slave using the Motive Pressure Pump? I had it pressurized up to 19lbs.

Feel free to make fun of me as long as you offer advice!! Geez, I feel stupid.

(on the other hand, I successfully installed a new turn signal/bright light switch and oil level sender --- though it reads even lower than the old one).

old man neri

Sounds like you did it correctly. The easier pedal acctuation is probably due to there being clean new fluid in there.

The bentley manual instructions worked perfectly when I bled my clutch.

911vet

You, sir, are a better mechanic than I.

Maybe I read the whole thing wrong. I tried multiple variations on the procedure and nothing seemed to work.

My brother pressed the clutch as I opened the bleeder. I closed the bleeder. When he let off the pedal, it stayed on the floor. With the bleeder closed, he pulled it back up by hand. We repeated multiple times... the best we got was a partial return. At that point, we were not pulling air in through the reservoir.

Unhappy with the whole thing, we did it again and I screwed up and didn't fill the pressure bleeder. So the reservoir got filled with air. After that, I ended up with no pedal at all. (pulled air in through the top).

I felt I was sucking in air when I was having him depress the pedal as I tried to close the bleeder. There's a moment when I'm trying to shut it and it appeared air was going back into the slave.

My apologies to Mr. Bentley, but I'm never gonna touch that pedal on a bleed again. I know I sucked air in that way.

old man neri

All I did was hook the pressure bleeder up to the resevoir, open up the bleed screw, work the pedal a few times, then with the pedal being held to the floor I closed the bleeder screw. Brought the pedal back up and have been driving the car ever since.

Did your steps differ?

Oddly enough I followed the same steps on my Honda and it also worked.

RacerX1166

Bentley book says press clutch a few times then open bleeder.

At this point, there is no need to bleed the master since bleeding the slave takes care of the master in the process. You may find, since you sucked a ton of air in, that you'll need to bleed it again just to get the last of the air out.

I had a similar OOP's that I won't go into but I wound up blowing air out the bleeder and needed to bleed the system twice to complete the job.

Of course, I've just diagnosed the reason the air was getting into my clutch was due to a faulty master so I get to do the job again.....

911vet

Thanks for the re-assurance.

I'm installing new brake discs this week, so I'll bleed the brake lines and the slave cylinder after that.

Heck, that Motul is cheap -- only $34/liter.

911vet

That's what I did last time - but the pedal wouldn't return on its own. Had to pull it up. I can't honestly say whether I closed it with it up or down though. I'm guessing it was up?? (had a friend helping and I don't remember precisely). I just know we pumped it while the bleeder was open and it wouldn't return on its own.

When I asked the "Porsche mechanic" about it, he said that by doing that, I pulled air into the slave. He said never to let the pedal come up with the bleeder open.

So, I figured I'd do it "right" today and get air out that I introduced before.
Maybe I've got a bad cylinder or something that isn't pushing my pedal back up? Or a bad spring? Don't know. Never had any problem during driving.

Amber Gramps

Shannon, the clutch pushes the pedal back up. If it comes back up on it's own....RUN!

I just went through this on my Nissan. I had just a wee bit of air and it wasn't allowing me to shift smoothly. I opened up the slave and had my son press the pedal down and he freaked when it didn't come back up on it's own. I had to get up, go around and show him how to pull it back up, get back down and start all over.

old man neri

Shannon,

I had a small hose on the end of the bleeder screw so if there was some sucking back in all it would do is suck fluid in.

-matt

Auto_Werks 3.6

Shannon, If you did it literally the way you wrote the procedure, then it probably contributed to your problems. Probably should have had him pump the pedal a few times, then hold it on the floor. While he holds the pedal on the floor, you then open the bleeder, and close before he releases the pedal. You may still have to pull the pedal up by hand (don't remember), but it should come back stronger after a couple pumps. On some systems I have found it helpful to actually close the bleeder before the fluid stops on it's own, to be 100% sure you don't suck any air back in. The power bleeder works too though Like others have already said, no need to bleed the master cylinder

rusnak

You can get extra 1/4" plastic tubing at OSH. It's where they keep refrigerator tubing, and it comes in a roll. I keep some around for bleeding brakes. I use a large mayonaisse jar with a hole punched in the lid as the bleed fluid container, and keep the hose end submerged, as Matt suggested. I usually bleed with cheap DOT 4 fluid, and then once bled, switch to the expensive stuff.

rnln

On many cars, I usually do the pumping pedal method and usually it works fine. Once in a while it doesn't work perfect for some reasons, I just keep on and on do it untill more air comes out. If the pedal works, the shifting is ok without grinding, you are done. The soft feeling pedal probably means your new fluid flows better than your old fluid.

RacerX1166

If your pedal is still on the floor, here's what I did to remedy the situation:
- Pump the clutch pedal
- Pressurize
- Bleed
- Release pressure (but make sure you've got fluid in your reservoir)
- Pump the clutch pedal
- Pressurize
- Bleed

Repeat until you have good pedal feel.

Curse two days later when the pedal is back to being mushy with too much play. Oh wait, that's only if your master has shat the bed. At least I'm being smart (like you appear to be) and replacing my frozen front caliper at the same time as my master since I hate working with brake fluid. At least I know where the bleeder screw is now and curse slightly less trying to get at it.

ron mcatee

I hope you know the brake reservoir is a common source for the fluid to the brakes & clutch slave. If you drained the reservoir, the brakes will need bleeding also.

911vet

Thanks everyone.
* I have a hose on the bleeder that's long enough to extend down to my drain can, so that was not the problem.

* I did close the bleeder before it quit draining to minimize air going back in, but it's not always a quick on/off so I think air sneaks in before it's fully closed.

* This is the third time I've done a flush/bleed. Previously, I pumped the pedal with the bleeder open the whole time. But a mechanic told me that allowed air back in --- that's why I was attempting not to bring the pedal back up while the valve was open.

* My big mistake this time was letting the pressure pump and reservoir get air in them... I pulled in a massive amount of air from above

* Yep, thanks, I am definitely aware that the clutch and brakes share fluid and I will have to bleed the brakes. They feel fine right now, but I'll bleed them after I install the new discs. I've got 5 track days on this fluid so I need to bleed it anyway.

Thanks everyone. I still plan to leave the pedal alone on the next flush/bleed!
It seemed a much better result when I left the pedal alone. I just pressurized the pump and let it push the fluid through. I got a very good, steady stream, and after all the air was gone, and after I drained another 1/2 quart from the point I saw no more air.... it seemed great.