clutch not functioning normally

[Gli_ryan]

This is sort of a long story, but the points of it have merit potentially. 1996 Passat tdi with 260k. I've had it for 60k.

I'll try to make the story short: my brakes started working poorly Thursday afternoon, Friday morning they were worse, after I got to work on Friday I checked fluid level and it was really low. Front right caliper was leaking. I filled the fluid. Brakes were working ok. Saturday morning I found the bleeder screw to be leaking fluid, I worked it in and out and then bled the brake. The brakes were normal. 5 miles later I was backing in to a parking spot and then could not get out of reverse. Thought linkage got jammed, so I turned off the car and pulled it out of gear fine. Went to leave and after starting the car I could not get it in to gear. Turned car off, pressed clutch and put in to gear. Started car and it was seemingly fine, could not get out of gear though.

The clutch is sort of working. It is like there is an air bubble in the line, but since Friday the reservoir has been quite full. I have bled the slave with no luck. I vacuum bled from the slave (or tried to) with a friends bleeder tool. I manually bled it again. I cracked the master cylinder pressure line and only fluid came out. I have ran a lot of fluid through the system while bleeding so far. I pulled the slave cylinder and nothing looked out of the ordinary, the fork in the bell housing feels normal. It feels like the clutch has worked almost enough at some points, still can't get in to or out of gear, but when running the car won't pull forward with the pedal pressed and in gear. Now the clutch is not releasing much at all and the car will move when started (feels like that has gotten worse).

I cannot hear anything out of the ordinary when pressing the clutch with engine running or off, so it sounds like the actual internal bell housing parts are functioning normally. I have tried bleeding the system with no luck. I can't see an obvious issue with the slave cylinder. Anyone have something obvious I'm missing? Next steps I suppose are finding a different bleeding system, replacing the slave and/or master cylinder, and then of course worst case scenario...

 

[garciapiano]

Sounds like the fluid got low enough (due to the brake leak) for the clutch master to ingest some air. So there is probably still air in the lines. Try bleeding again as a manual bleed might not be enough to get it out.

I typically use a pressure bleeder from schwaben that pushes fluid down into the brake master and through the clutch line.

Something else you might want to try is raising the front of the car so that air can work its way naturally out of the master. It's possible there is a bubble trapped in the cylinder.

 

[Gli_ryan]

I just ordered a pressure bleeder. I'll try that when it comes in. It seems to me if I put the nose down that will raise the reservoir higher than the bottom of the hydraulic system, since the slave is in front of the reservoir. But then the reservoir is in front of the master cylinder, so maybe it doesn't matter too much. I'm going to start out right now by letting the thing sit for a few days. Thanks for the tip.

 

[Steve Addy]

The pressure will assist in pushing fluid in and air out. It didn't take much for me to get the B4 clutch master bled yesterday when I applied a little pressure.

Steve

 

[Gli_ryan]

Not sure when the bleeder will arrive...but I tried the car this evening and what I found makes me think worst case scenario. Started the car and the clutch didn't work. Killed engine, put in gear, started engine. Clutch wasn't working well and the car tried to move for a second or two when kind of suddenly the clutch let go and was working. I was able to pull it out of reverse and put it in to first gear, I believe I did that one more time before the clutch quit working again. I tried this a few times, starting the car in gear and seeing what happens, and there was a degree of working shortly and then very obviously not working. I couldn't tell, but I thought I heard some noise that was weird, couldn't tell if it was related or not. So unknown correlation at this time...

Still waiting for the pressure bleeder, I won't be messing around with the car anymore until that gets here.

 

[Matthew13]

I've had a similar issue, but it comes and goes. The background: New clutch hydraulics (master and slave cylinders, connecting line). PO put a stage 2 clutch in. Bled with pressure bleeder. 99% of the time, everything works normally. All is well.
But every few months (like yesterday, for instance) the car will not come out of gear. It's usually at lower speeds like in a parking lot or backing out of my driveway. I find that if I pull the pedal up with my toe (the pedal doesn't sink to the ground but it feels like it comes up a smidge), then everything works.
Today, no issues. Maybe a bubble in the system somewhere? Ghost in the machine?

 

[Nuje]

If you know the fluid is clean (because you've pushed so much fresh fluid through the system recently) and you're tired of wasting brake fluid, instead of the bleeder hose going to a collection bottle, you can just run the hose back to reservoir.

This was after having used the pressure bleeder for some time already on my Mk4 clutch line; I let it sit for a while (10minutes), then did this setup.
You can see all of the bubbles that were still in the line. Did a couple reps of this (pump the pedal slowly a few times, close it off, let it sit, open it up, pump a few more times, etc.) and eventually got to no-bubble-nirvana.

 

[Matthew13]

Nuje - that's an interesting method of bleeding...will have to use it next time I bleed my system.

These hydraulic systems and all the complications make me wish for a clutch cable like on my 84 GTI or air-cooled stuff. They seemed to work just fine.

 

[Gli_ryan]

Got my Motive pressure bleeder. I carefully used it and pressurized the reservoir without fluid in the Motive tank. I pushed about 2 fluid reservoirs worth of fluid through the line. I saw a few tiny bubbles come out right at first and then nothing but good looking fluid came out. It filled a normal gatorade bottle up a little less than 1/4 of the way.

Started car, couldn't get it in to gear. Turned car off and put in to gear then started it. Like it has before the clutch seemed to be working at first. I could row in and out of gears without issue. Then I started releasing the clutch in gear. I think I was able to do this twice and then I couldn't get back in gear. The change from working to not working is abrupt.

I'm leaning towards worst case scenario..........clutch. Maybe the pressure plate, idk..

 

[Mcgink]

I have almost the same problem with I-Red. I believe that I have a broken spring in there preventing full disengagement of the clutch. Doesn't lurch forward or reverse when started in gear but definitely moves due to the clutch not having full disengagement.

 

[Gli_ryan]

I think that's exactly what's happening. You should fix yours, then tell me if that's it before I tear in to mine haha

 

[waymui@gmail.com]

I’m having almost the same symptoms after replacing the master and slave and bleeding multiple times. I employed the hose back into the reservoir method and pumped the clutch 50 times after the last tiny bubble of air in the line that I saw. Still I’m having troubles shifting into gears most times. Sometimes it will go into gear without problem. From a stop, if it shift into 2nd, then immediately go to first it will go in without problem 99% of the time. Shifting while moving then is difficult.
What did you find as a solution for your cars? Thanks in advance for the help!