Apex

Sorry for so many questions but I need a little help with this...

After replacing the pressure hose between master and slave cylinders - and bleeding from the slave cylinder three times (nice clear bubble-free liquid) the pedal still won't come all the way back. I can change gears, but only at the extreme far end of pedal travel - like the last inch or so! Brakes are great - didn't bleed them all around but did take some fluid from the front right caliper to draw down the last fluid from the Motive pressure bleeder and the fluid was also clear and bubble-free. I did a complete fluid change-out last year.

So the question is: what should I look at next? Everything seems tight. No leaks. Is it likely that one of the cylinders just happened to give way when the hose went? Is cylinder operation an everything-or-nothing proposition? If yes, the fact that I can still pressurize the system enough to release the clutch would indicate that there must still be air in there somewhere... but jeez I've pushed two or three liters of fluid through the slave cylinder bleed screw...

glencase

I had a similar problem when I did mine.
You might want to replace the blue supply hose first, they get pinholes at times and give you a good pedal for a day or 2 until the air seeps back in.

Did you use a pressure bleeder? or did you do it manually?
Is someone helping you do it?
What is the process your using to bleed?

I replaced the clutch master, slave, pressure line, and blue feeder line, to prevent being stranded again. When you do one I recommend doing them all.

First and foremost do not pump the pedal in an attempt to get it to come up, that will just make the air in the lines turn into little bubbles.

The process I used for bleeding was to have someone by HAND not foot pull the pedal slowly all the way up and slowly apply pressure to the clutch pedal at which point I would open the bleeder enough to let the fluid out.
get to the bottom of the travel lock the bleeder and do it again, and again, and again.

The key I think is actually pulling the pedal up after the bleeder is locked to get all the fluid that you can and out as much as you can.

If you know someone at a shop they can pressure bleed it for you or call and get a price.

It gets very frustrating but when in doubt bleed bleed bleed then bleed some more.

Glen

glencase

I forgot the most important part.

Jack the back of the car up as High as you can, I'm not talking change a tire height, I'm talking to the full height of a big shop jack.

Good luck.

Glen

Apex

Hey Glen thanks. I'm using a pressure bleeder, doing it alone, not pumping the pedals. I know what you mean about the little bubbles - the first time I bled the system I did move the pedal (by hand) and created a zone of froth in the line - but that all moved out of the system. Bled fluid it clear and pristine.

Tilting the car is a new idea - what's the mechanism there? Will air really get trapped in the difference between 0 degrees and 10-15 degrees or so that a jack will get you? Interesting!

I take your point about refreshing the whole system with new parts...

glencase

Jack just the rear up as high as you can and make sure you use large jack stands for safety, I used 2 big floor jacks under each shock/suspension point. At about a 30-40 degree angle, about as high as you can go without hitting the garage door/ceiling.

The theory behind it is that air gets trapped in the slave cylinder but lets the fluid out, the angle makes the air get to where the bleeder is and then you can get it out.

You may also want to crack the line at the Clutch master and manually bleed it, lock it down, then move down to the pressure line and bleed it at that fitting as well, then move down to the line on the slave first, then the bleeder.

Work your way down the system and jack it up, and bleed bleed bleed.

You'll be back on the road in no time.

Pressure bleeding should do the trick if you don't want to do it manually just pull the pedal to the correct placement jack that sucker up and bleed away.

How did you get a pressure bleeder or is it a hand pump style? If it is the hand pump style (I tried it and it didn't work) you may be better off having someone help you. Just remember to tell them up (locked bleeder) and Down open bleeder.

Glen

Apex

Thank you everyone for your helpful stories and advice - me and my 968 are back in business.

Couple of follow-up questions:

1) I replaced the blue hose - and while wrangling with the &(*^*% compression clamp at the master cylinder I pulled the plastic elbow fitting out of the rubber grommet securing it into the cylinder. Popped it back in and all seems fine. Have I created a leak in the system now? Is this elbow part of the master cylinder or a separately-numbered part?

2) After bleeding, I had full pedal return. Soon as I got in the car for a test drive, pedal only came back half-way. After driving for ten minutes - pedal started to snap back fully. No complaints - just wondering what would cause that behavior. Residual air? I was beginning the think the spring on the pedal was maladjusted...

glencase

Popping it back in is fine but it concerns me that your pedal only came have way up and then all the way when you had driven it for a while.

What process did you use to bleed it because you might still have air in the system.

If it did not do this before the issue you had and it is doing it now then you probably still have air in the system.

Did you start from the top of the system and work your way down?

Glen

Apex

Thanks Glen - the lil' grommet concerned me - it seems like such a loose connection compared to the other hard clamped connections - To answer your question I had the back of the car *way* up & used the Motive bleeder. Didn't work my way down. We'll see how the pedal is later this AM - I can live with an imperfect result for a few days since I'm changing out the cylinders next weekend and will need to re-bleed at that time.

glencase

Good choice, the parts aren't that expensive and it will give you piece of mind, everyone I've ever talked to says if something goes wrong in the sysem replace all the parts because the next on will go shortly.

Good luck,

Glen