My 411 project (tranny OK)

[haz]

That's the flat-hand slap I needed, thanks Ray Now, if I could only get a hold of these parts. I know I will probably be able to buy a "reparation set" for both the slave cylinder and master cylinder. But, if the pumps turn out to have rust in them, then a reparation set is no use.... If I could get a hold of a new clutch? I am not sure.. hope so!!!

When you say Vanagon, do you mean the T3 Transporter with a wbx engine? (Produced between 80-91?) Please specify. I also heard that the hydraulic pumps (the slave and master) work fine, but that you must weld some new fittings.

Now that we are in on that subject, are there anyparts (newer/older) from other models that goes onto this type 4 that I can use when doing this tranny and clutch job? I mean, since it's obviously hard to get a hold of these parts. Is www.bughaus.com my best shot at purchasing parts outside my own country? I saw they had some tranny seals under "transmission".

[raygreenwood]

I hope the slap did not hurt.
i have been there and done this so many times over my years of driving...that I just hate the damn clutch slave system on this car.

A couple of things.

The master cylinder...as long as you have no rust pits in the walls...can be rebuilt simply by stealing the outer and one inner seal from any type 3 or 4 brake master cylinder...along with the brass compensation port flap valve. You apply these seals to your pistons. Then...DO NOT hone the cylinder. lap it with 1000-2000 grit paper or with felt and very ffine diamond paste. The object is a very smooth wall....not cross hatching. These are not piston rings. The smoother the surface the better.

Or.....

You can use the master cylinder complete from a Vanagon. By Vanagon...I mean...what...1979 to I think 1982...angular body....air cooled enegine. Either way...last of the air cooled with hydraulic clutch.

Its clutch master was the same diameter, stroke length and volume as the type 4. It mounted differently....but one glance at it and you will instantly realize that you can simply mate up an angle iron plate to it and bolt it into the type 4. Or...you can simply steal the guts from it.

The clutch slave is a different story. I'm working on something for this now. It may take a while. But...I have rebuilt several of these over the years from readily available SAE sized seals. Usually they are a little tight and not the optimum cup design...but they worked. The problem is getting thr proper seal material.
Your best best is to locate an NOS kit or a new or rebuilt cylinder.

that being said....it does not solve the issue that the lifespan of these slaves is short...and in a year or two you are back to square one.

If you pull out the piston, sit down with a beer and a caliper and look carefully....you will see the defects that kill it. I'll list them so you do not have to think or measure while you drink....

(1) Looking at the piston you will see that the seal is down near the bottom of one end of the piston. You will also note that the skirt of the piston or the thin end.....on the pressure side....is the exact same diameter as the main body of the piston
This should shock you...as it means that the only fluid that gets past the skirt to inflate the cup/seal....is NIL! This means that the seal has poor inflation and sealing pressure on the walls of the cylinder....and very poor lubrication. this makes for high wear.
The best fix for this is to have some machinist chuck the piston in the lathe and reduce the skirt diameter. Or....you can simply take a round file and make about 8 clean groves across the skirt so fluid can bypass to the cups.

(2) The long main body of the piston...is too long...and needs support. Bear in mind that both brake and clutch master cylinders operate the same way. The pistons themselves do not seal the bore. The cups/seals do that and also center the piston in the bore. In fact all of these hydraulic pistons have excessive clearance to the bore....by design. The pistons are simply the support for the sealing cups. The clutch slave is no different.
Because of the long body.....the outer end of the piston "droops"...and rides against the bore. On high milage pistons you can see the wear marks on piston and bore. This also causes the main seal to "@@@@" slightly in the bore...causing excessive wear.

The best solution I can think of...is to chuch that piston in a lathe...and have a band of material about .75" wide and about .020" deep taken off. You will then fill that band with a strip of etched backed teflon of .025" thick...adhered with epoxy. Its a low friction packing. It will keep the piston centered in the bore.

(3) The outer boot is poor. Its subject to too much heat and braking dust and is not high temo enough. It takes about 1-2 years and it gets crispy and pops loose...allowing dust in...that kills the bore and seal. It should be made of either thin silicone sheet wired on...or I can cast a stepped version that collapses into the bore on retraction.

One last thing that should be done.
The type of seal that is on the slave is s "shaft" seal. It has the inner seal collar just like the outer seal of a master cylinder to keep fluid from from bypassing.

There is a company here in the US I have done a good deal of business with in the past. They can make a duplicate of the seal. I have used their seals before to rebuild the slave. The problem is this:
In the past (early 90's) they did not have the correct materials. Life was short...though the seal worked great. They have the correct materials now.
The other problem is that their seals are relatively high durometer...because they are cut from block material in a CNC multi-axis lathe. They do beautiful work...but the seals will be stiff enough that getting them on teh piston...will destroy a number of seals. I destroyed four getting one to work.

The ideal thing...would be to have the machinist...remove the seat end of the piston...the skirt end...with a sharp tool. Them..we install it back on with a center mounted screw...and a locating pin. All of that can be done on a drill press at home. In this manner..the seals can be bolted right up.

To do this.....you are probably looking at about $125 initial cost for design and layout and about $8 each per seal in a batch of about 50-75 seals.
That equals out to seals at about $10 each...of the right materials and dimensions.

I can make the teflon packings for about ...oh...lets see.....about 30 cents each....or 61 per 24" x 12" of material....in about 30 minutes.
I can recommend silicone sheet for the boot....or get busy casting one if everyone is serious.

If enough people are serious about a solution.....I can organize a group buy, make the teflon strips.....and draw up the machine sketch. The only two steps I would have the machinist do to save money...is remove the skirt and cut the band area for the teflon packing. Most friendly machinist shops can do this for maybe $50.
I found that just adding grooves on the skirt works great...and you can do the bolt and drilling at home.

In this respect...we can have a rebuildable slave. Ray

[haz]

Ok....here is the CORRECT logic path for working on 411/412 clutches.

(1) parts are scarce....so you do not want to waste them
(2) Good parts are even more scarce...so again...do not waste them.
(3) The clucth master and slave system design is not 100% excellent on this car....so its suspect.
(4) If you yourself...did not replace either the clutch master, the clutch slave or the rubber flexible hose leak between the transmission and the and steel line ....they are considered to be shot. Remember...you are working on a 35+ year old car. The clutch master and slave seals have a life of about two years before they start having issues....expecially if teh car is not driven much.

(5) When working on the clutch...it is false economy to only replace one part or another. When you pull the engine (a) Surface both levels of the flywheel (b) replace the pressure plate ...always (c) replace the disc...always (d) replace the needle bearing....always (e) replace the rear main seal, o-ring and felt ring...always (f) replace the transmission shaft seal...always.

(6) It is insanity to replace any clutch parts inside the bell housing without ALWAYS replaceing or rebuilding the clutch slave cylinder. The etxra strain will almost always make it leak...and they were prone to leakage anyway.

(7) it is false economy to replace one end of the hydraulic circuit and not the other...unless a particular cylinder is known to be very very young (i.e....maybe 6 months old at the most).

In other words.....if you put in a new clutch....rebuild the master and slave as well.

Its worthwhile to fabricate a solid steel to replace the clutch hose that is attached to the slave cylinder. So....steel line from the slave to the support bracket and clip at the tail of the transmission....then use....the flexible hose from a Vanagon from the same position. It bolts right up.

The later 44.5mm slave cylinder was defective in design in several ways. It has a short life.


Yes...start shopping for parts now. I guarantee you will need them.
If you plan to drive this car and have it be reliable, replace/rebuild the entire clutch system now....so you know its condition...then just refurbish the hydraulic parts on a two year interval and you will have no problems. Ray

ey! We've startet the job now. Got the parts and the time.. finally!!

First we lifted the engine out





Then we discovered something fishy


Closer look shows that the wheel had worn out the releasearm



And if you look at the washer thingy on the tranny, it is also worn out and bent down so that the releasearm does not work properly



We put a new in from an old tranny


And the slave was also broken, the ring thingy has broke in half



New parts, for the next work night (Clutch is ordered from Dalhems in Sweden, complete with all parts needed)

[Lars S]

Good you found the fault haz! Question: The heat exchangers on your engine looks wery shiny, are they new or?

/Lars S

[haz]

Have no idea, haven't really noticed. Remember, I never drove this car - I bought it in march and hace only been working on it indoors in the meantime

[raygreenwood]

Ok. Slow down. You have some common problems to take care of:

(1) The original defect here...and it is a defective part...is the small disc that holds the pivot point of the clutch fork. It will leave you stranded. As it craked and bent..and they all crack and bend because they are too thin....it allows the clutch fork to rub on the pressure plate. The damage you see on your clucth fork is CRITICAL. Even with no more wear...that clucth fork will start bending. It will eventually crack where the pushrod from the slave contacts it.
It needs to be welded on the inside and outside for strength.

(2) I can send you a simple sketch of what needs to be done to strengthen that pivot disc. Yours is missing a part that has worn off...as they all do. This is a very simple fix...but must be done.

Fix this problem or your system will (a) never have proper clucth leverage and (b) leave you stranded with no replacement fork to be found. Ray

[haz]

slowing down..... please send sketch raygreenwood, it would be much appreciated!!!

1. We did weld the clutch fork (the "E" shaped pivot disc) both in- and outside to re-inforce it, I mentioned that part, no?? Any more work on this we should consider?
You point out that the clutch fork has been in contact with the pressure plate, but I know this - and we will a) replace the fork and as you can see from the picture has the partt laying there b) we have already replaced a re-inforced pivot disc (the "E" shaped disc) and welded to re-inforce it. But please send that sketch, thanks

2. You are correct, that small part "died" when we removed the "E" shaped pivot disc from the other tranny, but we remembered to bring over that small and thin ring that keeps the pivot disc in place, to put ontop.

3. Where in Haynes can this -E shaped disc- issue be located, if it's even mentioned in there, because I couldn't find it being mentioned at all!

thanks again !!

[raygreenwood]

I have never seen it mentioned in any manual. Part of its problem is that its just too thin at the edge where it contacts that nice round pivot point on the clutch fork. Once that rolled over double edge wears off on the disc....failure is a matter of DAYS .
I went through three on one transmission in about four months before I finally fixed it.

This is especially so if you have the nice original 900+ pound pressure plate.
Lets see if I have your private e-mail. Ray

[haz]

i have sent you my mailadres on pm. Im actually in the garage working on the 411 right now, sending this via my Nokia! Just finished washing the engine. New problem tho: the "tube" that transports the brake fluid is shot and we couldnt find the correct size width which is 6mm only 4mm and 8mm

[haz]

Pictures from tonights job

Always nice with a clean engine





Master cylinder fitted



Here is a closer look at the broken parts



Here is the broken pivot disc that we took out, the metal is bent down and should originally go all the way down to the red line there



The challenge now is to get a hold of a copper tube/ line thingy in 6mm with to transport the brakefluid. Any tips on what to else to use?

[Lars S]

Haz,
you could try a refrigeration company (Kjölefirma) they should have 1/4" soft copper tube which is 6.35mm.

Still impressed of your heat exchangers, the metal looks galvanized or something similar (or you may not have as much salt as we have on the roads during wintertime...)


/Lars S

[haz]

hehe... I considered asking here, but afraid of being laughed at But now I got a hold of 2 meters of 6mm tube from Tess. But I that doesn't work.. I'll go for the refrigerate tip

[haz]

Thanks for the sketch raygreenwood!

I haven't had time to look at it yet, I have to take my 99 MKIV to the shop to check if the airbag-light in the dash is on for a reason, or if it's just a malfunction.

Does the sketch require any explanation or stepguide, or is it self-explanatory sp that I get the idea when I have the time to look at it?

Thanks, this is massively helpfull!!

[haz]

Quick question raygreenwood:



How important is it that the "reapir made part" is 100% 90 degrees? (see picture above) Because the part we have welded on the new pivot disc (see picture below) is a bit crooked. (We'll just removed that, so we can start fresh again)

Anyways, we will take it up again to do this job following your sketch. It looks very smart.

[raygreenwood]

Its rather important that this is straight....for a couple of reasons:

(1) Bear in mind that the stock clutch pressure plate....the original "G" part # at least...had about 1,000 pounds of clamping pressure...give or take. The clutch slave imparts several hundred pounds of force. That pivot point absorbs a lot of force. The force from the clutch arm will rotate that disc so that the edge of the cut-out is *90....or the clutch arm will try toride crokked and possibly bind the throwout bearing or rub...on teh guide tune around the shaft.

(2) If the disc for some reason does not rotate to be *90....all of the pressure from the clucth fork will bear on that one thin strip andsmall point...and it will crack again rather quickly.

The problem with this little alignment disc is not that the metal was of poor quality...but that the egd that meets up with the clutch fork is so very thin to be bearing that much pressure. Ray