Re: Hi, and by the way (clutch master cylinder) (long)

[Eddi Jew <jew@rysa.dtc.hp.com>]

Alan Cordeiro <cordeiro@avlna.com> wrote:

 > Hi all,
 > 
 > I back, as of last Friday morning/afternoon.
 > 
 > New E-mail address is cordeiro@avlna.com
 > 
 > and, now for the bad news.
 > 
 > Last Friday evening, while going home from work the clutch pedal
 > went down to the floor. I reached down and pulled it up ( I was
 > still in the parking lot ) and it seemed to be fixed.

Same thing happened to my '86 5000S last year. Wait awhile and it'll work
a few times, then fail.

 > Later it bottomed out twice on the way home at various
 > freeway interchange gear shifts. 

I tried not to use my clutch so I lugged it home. Pedal worked during all
10 depresses.

 > There seemed to be no fluid loss, and so I thought I'd bleed
 > the system to get out any grit/gunk. I definately cleaned it
 > out, ( should have long ago from the looks of the fluid ) but 
 > the clutch is still "intermittant".

Same. After finding out that the supply-side hose end is way up at the top
of the reservior, I don't (re)fill it on my inclined driveway anymore.

 > Has anyone else solved this problem for an '86 5k clutch. I beleive
 > all the 5ks have the same hydraulic clutch system.
 > 
 > Since there are no leaks, I think its the master cylinder, but 
 > there is this pedal return spring thing ( Bentley ) that seems 
 > to be related.

My problem was the master cylinder. After relacing it, the spring was able
to return the pedal.

 > ( I wonder if it was coincidance that a few hours after I got
 > back on the net that my Audi gave trouble. Perhaps there is a 
 > "Audi problem virus" on this net. )
 > 
 > Alan Cordeiro
 > '86 5KTQ

I'd attached Zafer Mehmood's great note on the steps to replace the
master cylinder (Is this archive material?). I did mine before his note 
and learned it the hard way.  Some areas to add/stress:

Step 6: To minimize the leaking mess, I clamped the rubber supply hose 
        with a simple tool made for this purpose. One of SnapOn's cheaper 
        tools, this has a wing nut on a threaded, L-shaped rod that'll 
        squeeze the hose against a tapered, metal die. Some other
        clamping device that is forgiving on the tubing would also work.

Step 9: The suggestion to re-use the old connector is a good one. I felt
        bad leaving an old part in there, but I timed-out struggling with
        it.

        I had a tough time replacing the clip back on the pin. I don't
        remember if I reversed the side the pin goes in so I could get
        that clip in. Another one on this list gave up on the clip and
        used a *very* strong magnet to hold the pin in place! 
        
Step 10: It took awhile, but I was able to bleed it the normal way. Might
         have something to do with keeping enough fluid in the lines.

-- Eddi
---------------------
From: zm@mhcnet.att.com (Zafer Mehmood  [209])
To: quattro@swiss.ans.net
Date: Wed, 26 Oct 1994 16:57:46 +0500
Original-From: mhcnet!zm (Zafer Mehmood  [209])
Subject: Re: clutch mstr cylinder R&R (long)

> A few weeks ago I replaced my brake fluid and noticed some on the _outside_
> of the clutch master cylinder.  
>   [stuff deleted] 
> Question 1:   I had a similar  leak in my '82 and it trashed a pair of
> leather shoes. The fluid dripped right on them and it ruined the finish.
> Has anyone else a similar story on the C3 (84-??)?
> 

Yes, I've had the fluid drip on my shoes and discolor them. This is on an
87 5000 TQ. I rebuilt the clutch master then. Worked ok for about 15 months
then the clutch pedal started sinking (wouldn't come up fully when held
depressed for sometime). Replaced it with a new ATE (OEM) cylinder from
Halsey Imports 2 weeks ago. Hopefully, end of problems for a few years.
Halsey (800-792-0081) was cheapest ($45.56) by far. Prompt shipping too.
I bought a brake master cyl from them a month ago also. Ask for Scott.

> Question 2: There is, as yet, no noticeable loss of fluid in the reservior.
> Is it right to think it will be 6+ months before it gets this bad?  Is the
> slave cylinder doomed to follow?
>
The leak probably isn't significant so you won't see an appreciable drop in
fluid level. But I wouldn't wait that long. Do it at your earliest
convenience. I don't know about the slave following suit. The previous
owner of my car had had the slave replaced before, so its been holding up
ok so far.

> 
> Question 3: It looks like a straightforward job.  Any hints?  How long did
> it take you?  Anything I should know?

Jason, your car is an '86 5000CS, right? R&R should be similar to my '87
5000CS TQ. Didn't take me too long the second time - about 2 hours is
reasonable. It took me longer since I was replacing the brake master cylinder
and experimenting with a home-built contraption for power bleeding the system
at the same time. Anyway, here's the procedure:

1. Remove parcel tray under dash
2. Remove lower part of the dash under the steering wheel. Not as difficult
   as it sounds - 4 *black* screws and slide it down and out. Unplug wire
   connector to a relay that sits on this panel (relay held to panel by 2
   gold colored screws - don't remove these)
3. Remove air duct that runs in front of the pedal frame.
4. Remove two inside hex screws holding the cylinder to the aluminium pedal
   crossmember. You'll need a 6 mm allen key. If the cylinder is original
   you may have to grind (or cut) the smaller leg of the allen key to about
   10mm in length beforehand. This is because there isn't enough space in
   front of one of the bolts to insert the key in fully. The replacement
   cyl was redesigned to eliminate this obstruction. You'll probably need
   to use an extension on the allen key for leverage - those screws are
   pretty tight. I used a deep socket with an extension on top of the allen
   key.
5. Remove the metal hydraulic fitting at the bottom of the cylinder. Be
   prepared with paper towels/rags to mop up the fluid that will leak out.
6. Remove the rubber hose (that connects to the brake fluid reservoir) at
   the cylinder end. The rubber hose is connected to the cylinder through
   a plastic connector. I suggest pulling the connector out of the cylinder
   leaving the other end of the connector in the hose. Mop up again.
7. Push clutch pedal in. Through a hole in the pedal crossmember you should
   see the cylinder fork connected to the pedal with a clevis pin. Remove
   the clip at the end of the pin. Push clevis pin out with a screw driver.
   The clevis pin can be removed by accessing it through a hole on the left
   side of the crossmember.
8. Take out the cylinder. Breath a sigh of relief and rest those aching
   neck and back muscles from the contortionist poses that you just went
   through under the dash.
9. Assembly is pretty much reverse of disassembly. Get the bolts on the
   cylinder back on tight, as also the metal fitting for the hydraulic line.
   Moisten the plastic hose connector with clean fluid before inserting into
   the cylinder. I suggest you reuse the old connector and save the
   new one that comes with the cylinder. I tried removing the plastic
   connector from the rubber hose - struggled with it for sometime and finally
   had to cut the hose off about 3/4". Avoid this if possible.
10.Bleed the clutch hydraulic circuit (brake lines should be unaffected).
   I have found that pressure bleeding of the clutch line is necessary.
   Alternatively, you can try the method posting recently here by someone
   else.

-----------------------------------------------------------------
Zafer Mehmood				   AT&T Bell Laboratories
zm@mhcnet.att.com			   Murray Hill, NJ