VW Automatic Register

Technical forum => Technical => Topic started by: sb001 on 30 March 2018, 22:51

Title: Those of you who've taken apart a clutch servo canister....
Post by: sb001 on 30 March 2018, 22:51
...how in the world did you get the metal band around the middle off????
This sucker is crimped on on both top and bottom sides, there is NO WAY I can get it off without ruining it!

Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: sb001 on 31 March 2018, 04:48
Never mind- I just noticed that the rebuild kits for these come with a new metal band to go around the canister, they clamp in place with a screw. So I guess you're supposed to destroy this one getting it off.
I've never had to take a canister apart before in 30 years of driving this car... I wonder if I'd actually be better off finding a good used canister, reading on some other posts about comparing the quality of the old diaphragm to the new one...
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: 68autobug on 02 April 2018, 12:44
Yes, I have a repair kit which includes the new metal strap ... best to all Your repair kits now while You can still get them...

LEE in Australia
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: sb001 on 02 April 2018, 17:50
One more question - the original diaphragm is connected to a center metal plate, like it's glued to it-- but the new diaphragm in the kit does not have the metal center-- how do i get the metal center plate separated from the original diaphragm to install the new one?
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: volkenstein on 03 April 2018, 09:57
sb001,
         It shouldn't be. Go down to members step by step. I have disassembled one there, from the old forum. The piccies work, INCLUDING - how to rip the original sealing ring off.

Regards
Volkenstein
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: sb001 on 03 April 2018, 17:55
Thanks volkenstein!!
P.S. Here is the small tear I found in my diaphragm-- could this really cause enough of a vacuum leak for the car to have extreme difficulty shifting into gear??

(https://www.thesamba.com/vw/gallery/pix/1764085.jpg)
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: 68autobug on 04 April 2018, 03:26
Hi Sean,
I haven't taken a diaphram off but it looks that the center part of the rubber diaphram is bolted between the two pieces of steel..
It doesn't take much of a hole to stop it working correctly...

LEE
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: sb001 on 04 April 2018, 06:39
Thx Lee- my name is Steve BTW  :D

Although that reminds me of one time in 3rd grade, when I was reading a story out loud in class and came to the name Sean, I correctly pronounced it "SHAUN", the teach er said I was wrong and it was "SEEN." I said "what? are you stupid?" And got immediately sent to the principal's office. The principal just laughed.
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: volkenstein on 04 April 2018, 09:32
 ;D ,
      Gotcha both then...Stephen Sean is the start of my lunatic family tradition.
Anyway - yeah, that tear will definitely cause shifting issues.

Just remember - the vacuum is coming via a 12mm ID hose - it won't matter how big your vac can is. It'll lose vacuum straight away as air will enter via that tear and
attempt to equalise.

Re - the two halves...inner portions seal the inside, the outside diameter seals so effectively creating the vacuum seal. Sb's example looks like it has just been a typical victim
of age & vacuum & movement over time has caused the rubber to split.


HTH
Volkenstein
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: sb001 on 04 April 2018, 14:55
;D ,
      Gotcha both then...Stephen Sean is the start of my lunatic family tradition.
Anyway - yeah, that tear will definitely cause shifting issues.

Just remember - the vacuum is coming via a 12mm ID hose - it won't matter how big your vac can is. It'll lose vacuum straight away as air will enter via that tear and
attempt to equalise.

Re - the two halves...inner portions seal the inside, the outside diameter seals so effectively creating the vacuum seal. Sb's example looks like it has just been a typical victim
of age & vacuum & movement over time has caused the rubber to split.


HTH
Volkenstein

Thanks tons Volkenstein! This is the first time in the entire life of this car I have ever had to replace the diaphragm inside the canister--that's almost 50 years with zero problems with the canister!  :o  It really does make me wonder if I should find another good used German one and bolt it on instead of going with one of those aftermarket rebuild kits. I know those are popular but come on- 50 years without a problem?? The proof is in the pudding- or the canister as would be the case here...
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: 68autobug on 05 April 2018, 02:49
Getting a good replacement used cannister [clutch servo] really depends on where it has been stored and how long was it used... Remember that no one really makes anything to last 50 years, it was just that Germans made many things as good as was possible.... with the best quality materials available back then...
replacing the diaphram with a new one should guarantee many more years of service.... maybe not 50 years though??


Lee in Australia

Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: volkenstein on 05 April 2018, 02:54
Sb,
    I have three (experimental subjects) additional ones. Those piccies came from the one on the car. Lee & myself & Bookwus (RIP) did some offline comparisons
and found differences relating to the adjustment centre stud. Also - I will state that the rubber quality of the replacement kits isn't as good as OG German (surprise, surprise).

BOT. Two of these cans had the crimped on rings, 1 had been previously rebuilt. I found (thanks to the Mityvac) that the large bore vac fitting on 1 had worked
itself loose - over time & abuse? Also found that on the one I rebuilt....a word to the wary I guess.

What I would try and do (and did) was to make sure once it was 90% assembled, with the new ring *just* snugged - was to make sure the diaphragm would butt up against the bottom of the can (vac side) and THEN tighten the crew clamping the two halves.

Another potential source of parts (IIRC with rotten memory now) is Truck Air Brakes. The OD is relatively standard. Something to take up later?

Sh ones - well - note what I said above. Here in Aus - more co$t effective to buy the rebuild kit than hunt for an unmolested one.


HTH
Volkenstein
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: bhartwell59 on 06 April 2018, 00:48
I have no problem with the rebuild kit... the rubber bladder was supple and flexible.

The only issue is the new screw-down metal band/ring that compresses the two halves together is fairly thick. Oh well, easier to repair in 40 yrs.
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: paulheger on 12 April 2018, 08:02
I had quite a though time getting the new metal band in place. It seems to be designed to compress the two halves when its getting tighter, but the quality is not that good that it can hold the torque to do so. Be careful, the two plates that hold the srew can't handle that much force. I used some clamps and vise to hold the two halves together with a little push, then the metal band will slide on and can be tightened.
Btw. To get the original band of: make a little start, grap it with a Lineman's plier and start twisting/turning. Works really easy.
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: autonewbie on 12 April 2018, 16:57
I just replaced my servo diaphram yesterday. All was easy except getting the band on.  I had to use a longer bolt to get the band started and I also applied a very thin smear of grease on the INSIDE (back) side of the band. I had hoped it would make the band slide and conform easier. It was still tough but it is now on and all works well.
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: sb001 on 12 April 2018, 17:39
Thanks all! I look forward to fighting this band clamp when I get my repair kit in...  ;D
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: 68autobug on 13 April 2018, 03:45
Not looking forward to ever doing this.... :D :D :D :D


Lee
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: sb001 on 15 April 2018, 00:09
Whew! Got the repair kit in today-- canister is fixed and back together:

(https://www.thesamba.com/vw/gallery/pix/1768088.jpg)

You guys weren't lying, that band clamp is a pain to install. The only way I was able to do it was using those large vice grips off to the side in that photo to hold the two ends squeezed together and just managed to get the bolt through and the nut spun on.

I wasn't able to keep the servo arm quite centered coming out of the canister, but the can seems to be holding vacuum fine, so I guess it's OK.
Hope I don't have to do that again for a while. Thanks to everyone for your help!
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: autonewbie on 15 April 2018, 01:53
Glad you got it all together.  Not a fun job and the bolt they supply was too short for me. I used a longer bolt and once it was all together and tight I then cut off the end of the bolt.
Happy motoring!
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: 68autobug on 17 April 2018, 09:13

So long as it works !!!


Lee in Australia
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: sb001 on 17 April 2018, 20:04
Hey guys, dumb question- there are spacers that go on the mounting bolts for the clutch canister. When i took my canister off, I did not look to see whether they go on the outside of the bracket (clutch arm side) or the inside of the bracket (up against the canister.) Can someone enlighten me? Thanks!
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: autonewbie on 18 April 2018, 01:37
Up against the canister so They are sandwiched between the bracket and the servo.
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: sb001 on 18 April 2018, 04:19
Thanks! I found an old photo I took a couple years ago that I posted over on the samba, it showed what you said.
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: Speedsterautoshift on 31 January 2019, 22:20
Hope your new diaphragm does not squeak and then stop giving you a smooth take off.  Mine did this so the clutch does the change fine in top two gears but is a bit rapid and crunchy in first and reverse.
But when first fitted it was a dream.

Maybe some french chalk on the rubber?

John
Title: Re: Those of you who've taken apart a clutch servo canister....
Post by: 68autobug on 01 February 2019, 06:22
I always advise to adjust the clutch adjuster until You can go into reverse without crunching...   Once You can go into reverse without crunching then the system is working great...
Once You have replaced the clutch servo bladder then You probably need to re-adjust the clutch so no crunching...
if it doesn't crunch in reverse then it won't crunch anywhere else...

Lee in Australia...