Vanagon – syncro clutch slave cylinder replacement adventure

Seems to be a real busy time of the year for me, just the time to put a new slave cylinder into the old syncro. It had been leaking for a few weeks, but it still worked the clutch. I procrastinated replacing it until I felt like hurting myself.

I’ve swapped in a slave cylinder a couple of times on a 2wd vanagon, I4 powered ones at that, and it was not that bad. But the stock motor in the syncro makes access to the bolts holding the slave to the bracket really painful. The rear most bolt is somewhat accessible front he engine compartment but the nut for that bolt is pretty well hidden by the bracket. A good fix for that is to weld that nut to the bracket so you only have to deal with the bolt and no need to hold the nut. The front bolt is somewhat easy to access, from under the van. I tried to get those bolts off, but I couldn’t. I even bent a wrench to get it in there, but no luck. I had heard that some folk take the bracket and cylinder off as a unit and that means taking the actuating arm off the shaft that goes in the bell housing (and moves the throwout bearing). There is a cir clip on the end of the shaft and theoretically, on a brand new van, when the clip is removed you can slide the arm off the shaft. I don’t see how you can do that easily on any van that has seen any kind of use. The arm is on there but good.

I had a spare arm (and shaft) so I decided to grind the arm off. I used a steel burr on a die grinder. Yes I chewed up the shaft, I got sloppy. But I didn’t do enough damage to make the replacement arm a poor fit, still went on tight.

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I tagged the bracket too.

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The arm.

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Now it was just a case of removing the 13mm head bolt on the bracket support strut and the 17mm bolt holding the bracket to the bell housing. Then you can ease the assembly down and let it hang by the hydraulic line. Great thing here is that the syncro has a flexible nylon line to the slave (and banjo bolt) rather than the steel line of the 2wd.

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I had the new, FTE brand, cylinder already to go, bolted to a spare bracket. A bracket from a diesel vanagon… yes, you know what’s coming.

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I had welded the two nuts to the bracket, here is a pic of the front nut. Yes, you know what’s coming.

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Quick with the swap over and now bleeding with the cylinder hanging.

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And up it goes into position… except I forgot the support arm is held to the bracket by that front nut which I had welded on. Doh, what a bonehead, ok off it comes with the zip disk. Right, up again with support arm attached…except it didn’t fit. The support  arm would not line up with the bolt hole in the transmission. Son of a bitch. Out it comes, let’s compare with the old bracket.

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Gee, whaddya know? They are different. It takes a special kind of bonehead to assume a 2wd diesel vanagon bracket would be the same as a wax syncro bracket. I am that special bonehead.

And, to add insult to injury, after cleaning off the muck from the bracket I could see someone had brazed on the rear nut and had brazed on the nut to the support bracket. So i could have removed the slave by itself after all. Well, no, not really. The bolts were in there real tight. Even with the bracket held in a vise I had to grunt with the spanner to remove the bolts.

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Righty oh then, back to the van to install new slave and old bracket combo. All went well, replacement arm on shaft, cir clip in place, slave bled. I tried the clutch pedal. The friggin pedal stopped hard about 2″ above where it should stop, no clutch activation. What the heck was going on?

The arm would move when the pedal was depressed, but only a little way before the pedal felt like it was hitting metal. I pulled the push rod from the slave and compared it with the one from the old slave, it had a longer effective length. New push rod at the bottom of the pic.

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With the rod removed the clutch pedal would not move, with the shorter old rod the clutch pedal would move down a bit, with no rod and the bleed screw open on the slave the pedal would press down full range. Can you guess what was up? I couldn’t at that point. I talked to Dave the mechanic, we both were stumped but were leaning to an internal problem, perhaps the throwout bearing retaining springs had come adrift. Looked like a tranny pull. I was so desperate that I looked on the Samba and found something interesting, here is the thread. Now I had some hope, so I quickly made a bit of an extension using the old rod (I removed what remained of the plastic that was inside the metal cup end) and some polyethylene.

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I made a hole, stepped hole, to mimic a socket to engage the ball on the lever arm. I installed it and yes, more pedal travel. Not quite enough so a made another using some Delrin rod. Here it is. BTW, it is a press fit into the metal socket.

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And, yes, success. Clutch works just like it used to, perfectly. Man, I was relieved. The modified pushrod had overall length of 112mm, socket in the Delrin was 4-6mm deep giving an effective rod length of 106-108mm. That’s  18-20mm longer than the new FTE push rod.

So what the heck was going on with the new slave? As I didn’t want to take it out and measure I can only guess that the new slave had a shorter piston stroke than the old one. And even with a longer push rod it was not enough to fully activate the clutch. And before you ask, I did have the slave cylinder properly installed in the bracket. I wonder if the syncro bracket locates the slave higher from the arm than the 2wd bracket?

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  1. #1 by famillysyncro on June 22, 2014 - 8:23 am

    Morning Alistair

    Looking at your post, I guess I’ll take care of that before I’ll put back the transmission on the van……
    I didn’t want to replace it as some of those old parts are better than new one but……
    The end of the shaft is damaged too, making the arm of the shaft removal almost impossible….. well, I guess it might be easier with the assy in the vise…..

    • #2 by albell on June 22, 2014 - 8:55 am

      Hi Jerome,

      I’m a little embarrassed by my careless grinding of the arm, hitting the shaft a bit. But it doesn’t seem to make any difference to the fit of the arm to shaft.

      Still puzzled why the new slave would not fully activate the clutch. Perhaps the piston stroke length is the same for the old and new slaves but the new slave piston travel is located higher up? Why don’t we hear about this more often?

      Somewhere, perhaps van cafe website, there is mention of working, polishing, the “ears” on the throw out shaft, the cross shaft. Making them smoother which helps in preventing or reducing clutch chatter.

      For sure you should weld on the nuts to the bracket. The rear nut to bracket proper, the front nut to the support strut. It might be that your engine allows better access to the rear bolt from engine compartment.

      Cheers

      Ab

      >

  2. #3 by Pz on June 22, 2014 - 6:45 pm

    Gads, you dah man with: stick to the problem until solved. Like glue!

    All this while FIFA matches are on-going…:-)

    • #4 by albell on June 22, 2014 - 10:51 pm

      Hi Phil,

      What else could I do? Friday night I was expecting to be pulling the tranny on the weekend. Thanks to the samba thread and just a little thinking I figured out the problem. Do you think the syncro slave cylinder bracket is different than the 2wd bracket? ( wbx engined).

      Or could it be I got bum slave?

      Cheers

      Ab

      >

  3. #5 by Pz on June 23, 2014 - 8:07 pm

    Shoot!
    Sorry, I do not have an Opin if the slave cylinder brackets are different between a 2wd/4wd T3.
    A look at the EKTA will answer this.
    My best guess? As the transmissions are different, I would wager a good guess,
    the slave brackets are different.. even between model years perhaps?

    Strokes to you. You got the job done!

  4. #6 by Robert Watters on July 27, 2017 - 11:30 am

    Good pics! Made things clearer on my 2wd 1982 air-cooled (LPG powered) after forgetting how to put things back together after replacing fried clutch. (First and hopefully last time)
    The bolts on the slave cylinder are definitely a pig. This was my second time putting slave back and even with all the spanners it’s still a pain.

    • #7 by albell on July 27, 2017 - 1:19 pm

      Glad it helped Robert. Yeah I found it to be a right pain too.

      Cheers

      Ab

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