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Wed Apr 23, 2008 4:23 pm

The clutch pedal on my 87 has about 1 to 1.25 inches of loose travel before the you can feel the actuation. There is little play in the shaft, and it feels as if it is all in the pushrod adjustment.

In the Bentley, it says to remove the instrument panel to get access to the top of the clutch master. I popped off the steering column, and took out the dash pod, - Brake fluid reservior, servo, and master blocking my view of the clutch master.

Am I really going to have to take the whole dash off to get to it? I've removed the dash in T2's, but not in a Vanagon.

I searched on the subject and I didn't really see anything definitive about the adjustment.

Thanks all!

Chris

Wed Apr 23, 2008 6:11 pm

There is no adjustment. It's hydralic. If you have no leaks and you have excessive pedal free play, then the clutch is wore out. Time to replace.

Wed Apr 23, 2008 9:25 pm

No, but ceebers is right, there should be a pedal pushrod length adjustment. Freeplay in hydraulics, brake too, should be 1/2" as measured at the bottom edge of the pedal. The piston plunger has to be able to always return all the way to expose the reservoir port. This lets the pressurised system keep filled, and always equalise its pressure at rest with the outside pressure so the system isn't preloaded. Without adequate freeplay, pressure can be trapped in the system, so it can make brakes drag, or a clutch slip.

But, I could never find a way to adjust the vanagon clutch master either. There doesn't seem to be any adjustment on the pushrod, or the pedal.

Thu Apr 24, 2008 2:13 am

Tencent, it's possible, but it's a bugger of a job.

If you really need to do this, then your clevis pin and the tab on the pedal itself are already worn out junk. You'll have to replace both the pedal (or weld the tab and then re-drill it) and the clevis pin to take out the slop. You'll see your pin is hourglassed badly when you pull it out.

With a new clevis pin & new pedal (or a repaired & re-drilled tab on the existing pedal) you should not have to adjust anything.

But if you insist, I think somebody on the Vanagon e-mail list rigged up a tool with a 5/8" spark plug socket.

If you move the clutch master out of the way (just unbolt from firewall and gently push it with hydraulics attached), you can slide the 5/8" spark plug socket up and over the vertical pushrod (by feel, because you can't see what you're doing). This pushrod has a lock nut at its base, and the spark plug socket fits over it.

The pushrod ends up poking out the square hole in the socket that is there for attaching the ratchet. So because that hole is blocked, then you have to get another socket in there to fit over top of the exterior hex flange of the 5/8" spark plug socket (measure the size of this flange first, before the spark plug socket disappears up into the netherworld...). By means of these two sockets joined together, you should be able to undo the lock nut with a ratchet. Once loose, that lets you screw the pushrod up & down.

Once you get it "about right", re-mount the clutch master in place and test pedal action. If you're ok, then pull the clutch master AGAIN and tighten the lock nut, then replace the master AGAIN. Trial an error will break your spirit here.

I was happy enough with the pedal action when I repaired the pedal tab and replaced the clevis, that I wanted nothing to do with this job. Just passing on an interesting technique that I read about a few years back.

Thu Apr 24, 2008 3:36 am

Like I said, not an adjustable system. You would never adjust the rod length to make up for clutch wear. Never. Nor do you do this to get brake pedal on worn or crappy brakes.

I've seen many Beetles with the brake pedal rod extended over the factory recommended "pre-load" to get the brakes to engage at a lower travel. This causes the master cylinder to basically be applying brakes without you pushing on the pedal . A sure sign of this is when the brake lights are permantly on, without the person applying the brakes.

I'd guess it would be the same way with the hydralic clutch. That 1/2 inch adjustment will never go out, unless someone removed and messed with it. It's not used to make up for a worn out clutch disk.

A "band aid" fix for a problem that is not being repaired correctly (or safely).

Thu Apr 24, 2008 7:59 am

Me bucko, I don't think you grasped the question. You're confusing freeplay with free travel. They're two stages of pedal movement, but are dealing with different things. You're right that if there's too much free travel of the hydraulics before you get braking or clutch effort, then at the master is not the place to deal with it. And that kind of free travel should never show up in a hydraulic clutch system. It will show up with drum brakes, which is a sure sign they need to be manually adjusted, but it should also never show up in 4-wheel disc systems. If it does it's a sign that something's wrong with the brakes themselves, or the actual clutch mechanism.

There's pedal or hydraulic travel before engagement, which you're talking about, and then there's play in the pedal linkage. You have to be able to establish free play of the pedal before the pushrod engages the hydraulic piston, for the reasons I explained, which it's clear you do understand. And it's not just to compensate for wear in the pedal linkage, which is important. I guess you haven't replaced dozens and dozens of master cylinders on various cars, maybe you have, but they don't all fit the same way even though they are the right part. Production tolerances from differing manufacturers and model years means that every one isn't going to fit the same, and you end up with varying amounts of free play, and the need to compensate for it somehow. There must be enough free play to let the piston return all the way back, to expose the reservoir port, but there can't be too much or the limited range of pedal swing is wasted and you can't get sufficient travel under hydraulic load to have either good braking effort, or full disengagement of the clutch.

No one was talking about correcting actual clutch action by pedal adjustment; ceebers was asking a very important quesion about getting the excessive free play out of his pedal linkage, and VW didn't provide for this with any convenience in the case of the Vanagon clutch. I guess they figure their linkage will never wear out and all the replacement masters will be built exactly the same. Imagine that.

Thu Apr 24, 2008 9:04 am

Exactly tencentlife. I just replaced the clutch and related about 6 months ago, this is freeplay in the piston to clutch master. I have about 1 to 1 and 1/4 inches of freeplay in the pedal before you feel the begining of resistance, and hence, the clutch hydraulics start to actuate.

In the Bentley they give you the tolerance for adjustment, but don't really go into how to make that adjustment. In an old Muir book I have he tells how to adjust it Type 4's, and said it related to Vanagons as well. Seeing how I haven't taken the whole dash off yet to even get a look at it, I'm not sure;-)

Thu Apr 24, 2008 10:19 am

The clutch and brakes operate differently so you can't directly compare the two. You apply pressure to set the brakes whereas you apply pressure to release the clutch, exact opposites. Drum brakes have an air gap between the shoe and the drum however small, whereas clutch lining are under pressure and have no air gap when the clutch is engaged. Hydraulic clutches are more similar to disc brakes in that most are self adjusting, in the case of the calipers there are no return springs to cause an air gap and in the case of a clutch once you have engagement there is no longer spring pressure to cause the slave cylinder to compress further.

With a worn clutch your pedal travel should be pretty close to the same as for a new clutch, you will just feel less pressure as you push down on it.

Thu Apr 24, 2008 10:59 am

Wildthings wrote: The clutch and brakes operate differently so you can't directly compare the two.

Sure you can, and as far as what this topic is about, you should. The hydraulic systems work the same. Both types of master cylinders have to return to full back stop to correct fluid volume as friction surfaces wear and to equalise pressure at rest. There are no important differences as regards the original question. What happens downstream is somewhat different, the main diff being that the brake system has to take on more fluid to compensate for wear, while the clutch has to lose fluid to compensate, but where and how they do that presents exactly the same requirements at the master cylinder. If you understand how one master works, you understand what both need.

Thu Apr 24, 2008 11:31 am

Always a good day when I learn something, even though I find it somewhat strange that another clutch master cylinder (or clutch slave cylinder) would require the rod to be adjusted.....I could understand rod wear, but that just goes back to my original statement that if it's worn, replace it.

Thu Apr 24, 2008 11:35 am

-that's what I'm sayin!

Thu Apr 24, 2008 2:10 pm

Ceebers wrote: I have about 1 to 1 and 1/4 inches of freeplay in the pedal before you feel the begining of resistance, and hence, the clutch hydraulics start to actuate.
Man, that's huge slop in the pedal/pushrod.

As 10c says, your new clutch master may be slightly different than your old one. But even so, with that much mechanical slop in the pedal, you're a candidate to replace your pedal and/or clevis pin.

There is no bearing fitted between the clevis pin and the hole in tab on the clutch pedal, so they grind away at each other over the life of the van.

For all the hassle of using 2 sockets to adjust that pushrod length, you're further ahead to pull the pedal out and do the proper repair.

If you fill in the ovalized hole in the tab, and then re-drill it centred in the tab, and then fit a new 1/4" clevis pin, you should not have to adjust the pushrod length.

Neil (Vanagon Nut) has a web page up with photos of his own repair to the pedal. See http://web.mac.com/tubaneil/iWeb/Site%205/ClutchPedalRepair.html

I was shocked when I pulled out my clutch pedal (at about 250K miles on the van). The tab for the clutch pedal was so worn, it wouldn't have taken many more shifts for the clevis pin to break right through it. The 1/4" clevis pin was hourglassed and worn to about 1/8" in the centre.

Thu Apr 24, 2008 5:05 pm

Oh, yes, definitely that much freeplay is pretty extreme, and might be more than could be adjusted out even if you tried. it does sound like the pedal arm and clevis might be pretty worn out. I got sidetracked explaining the need for free play, but absolutely, Joe, the short answer to the original question should have gone,"yes, there's a little adjustment but it's a bitch to do, but with that much slop you must have worn-out hardware. Tend to that first, then finalise the adjustment, if needed, when the linkage parts are tight again."

Whew!

Sun Apr 27, 2008 3:52 am

Mine has this same problem. how difficult is it to remove/replace pedal arm? From Vanagonut's pics it looks like it's the arm that needs to be replaced not the whole assembly.
Any tips would be appreciated.

Sun Apr 27, 2008 2:50 pm

I need to do this as well, I have as much freeplay or more in my pedal as ceebers. I've been trying to figure out how to deal with the pedal and I think I'm just going to do it when I pull the dash to put in a new blower. Should be fun.

Sun Apr 27, 2008 5:10 pm

seans67 wrote: I need to do this as well, I have as much freeplay or more in my pedal as ceebers. I've been trying to figure out how to deal with the pedal and I think I'm just going to do it when I pull the dash to put in a new blower. Should be fun.
That's how I got my clutch pedal out, when I pulled the dash to do the heater blower, core and wiper motor all at once. It's been 3 - 4 years for me now, so details aren't really precise in my memory.

The Bentley diagram was a bit confusing IIRC. Both the clutch and brake pedals hang off the same horizontal rod, but the diagram shows the clutch pedal seperate from the whole assembly, in mid air. Confusing to see, until you recognize the brake & clutch are pivoting from the same rod.

I recall reaching back there blind, with a vice grip, and pulling off the C-clip that prevents the clutch pedal from sliding laterally to the left off that rod. Then I wiggled the pedal out and up, into the area vacated by the instrument cluster.

I think there are some posts suggesting that it's possible and easier to pull that whole rod assembly, complete with both brake and clutch pedals. I don't know anything about any other way to get it. Maybe Neil will see this thread and post. There aren't really going to be pictures to help, as most of the work is done blind, by feel.

Sun Apr 27, 2008 5:12 pm

brooklynvan wrote: Mine has this same problem. how difficult is it to remove/replace pedal arm? From Vanagonut's pics it looks like it's the arm that needs to be replaced not the whole assembly.
Any tips would be appreciated.
That arm (I called it a "tab" above) is welded to the pedal. They are effectively one piece. You have to remove the whole pedal.

If you're a real hotshot, you'll install an oilite bearing when you fix the tab and replace the clevis pin. I didn't bother, as the first one lasted 250K miles. I'll probably have to pull the dash again in another 250K miles!

Mon Apr 28, 2008 5:10 pm

Maybe this has been said but I just wanted to throw in that there is another scenario between a leak and bad clutch the fluid could be low enough that the system could "inhale" some air over a bump or just over time. I think it's prudent to bleed it back at the slave cylinder before tearing it apart and replacing a possibly good clutch. My two cents. Todd

Sun Jun 01, 2008 3:32 pm

I found brake fluid dripping from my clutch master cylinder, so I am putting in a replacement. I found there is no freeplay between the push rod and the piston, I have to compress the spring in order to get it bolted in place. During the bleeding process, I am still getting a drip on the floor. With a new master, where else can it be leaking from? Is the lack of freeplay causing this? Now to crawl under and try to adjust.

Mon Jun 02, 2008 9:41 am

to the original poster:
1-1/4" seems like an incredible amount to come from wear. The slave cylinders when made by two different manufacturers (Ate and Febi?) take 2 different lengths of pushrods. It could be possible to create such a situation by interchanging parts of the two. If I understand it correctly, you should have no problem pulling the pushrod out from the release fork lever on the tranny and measuring its length. Then try to get the brand name from the slave cylinder.
OR, just get a new slave cylinder. This is easily the part I've replaced most on all the Vanagons I've had. IOW, if you don't need one now, you will in a few years.
Al