The Coupe Quattro
Ongoing Restoration
Info / Data

New Clutch Master and Slave Cylinders

I seem to have omitted recording a few events, which were

1. Starting engine for first time.
2. Setting ignition timing
3. Changing Idle Adjustment screw (seized)
4. Removing Cambelt covers and fitting the 2 bolts that I had omitted to put in the oil pump housing.

So once I had all this done, and the engine running nicely, I decided to take the car for a spin around the garden. Started the engine, and pushed down on the Clutch pedal. Which was stuck....... So I pushed a bit harder, and the pedal leapt down to the floor. And stayed there..... I pulled the clutch pedal up manually, and tried again. This time is was really solid, and stayed that way. 
With the engine runing, I tried selecting gear, which worked, but the car remained static.......
The implication was that the clutch had stuck in the open position.
This caused no end of cursing. Either the hydraulics were foobarred, or the mechanical side of the clutch was the culprit, and a potential gearbox removal loomed large in my imagination...  
After discussing this with a few other owners, and forum members, I decided to tackle the hydraulics to see if that was the problem. I already had a new Master cylinder (ebay again), a local supplier had a Slave cylinder on the shelf. 

So I decided to start with the Slave cylinder. Which is located on top of the gearbox, under the steering rack. Not very accessible.....

The bleed screw and hose connection.

The Slave cylinder is supposed to be secured by a roll pin through the gearbox casting, Mine seemed to have a Split Pin instead. You can just see the head of the pin here. It turned out that mine had a rollpin, and a splitpin........

Master cylinder access panel removed to check that there was no linkage problem.

Flexible hose conection undone to allow the Mud (technically brake fluid, but more like Mud.....) to drain down. Once the fluid had drained down, I checked the clutch again, problem still there.

Mud....... with lots of bits of rubber

You can see the rollpin here, I used a punch and the "Hammer of Thor" to remove it. I learnt here that plenty of light is vital, so that you can see exactly what you are doing. For a while it looks like I was just trying to punch a hole through the casting. 2 mins after getting additional light, the rollpin was out. I also had to remove the non-standard splitpin which was inside the rollpin.

Once the pin was out, I needed to remove the slave cylinder. This was accomplishing by getting a long drift onto where the bleed screw fits, and tapping the cylinder towards the rear of the car until it came out. It came out without it's pushrod, whih gave me some grounds for concern. However, it was located in the hole in the gearbox, and removed. If it had been totally missing, the gearbox would have had to be removed to find it. 
Once the cylinder came out, the clutch plate was back on the flywheel, indicating that this was the problem.    

The missing pushrod. 

I pre-fitted the hose to the slave cylinder (yes I know that I used the old hose, but I didn't have a new one, and I wanted to get the job done.......). The machined faces of the cylinder were coated in copper grease, and the cylinder inserted. The rollpin was reinserted to secure the cylinder to the gearbox.

The flexible hose was reconnected here. Be real carefull, as it's very easy to cross thread this connection, as it's hard to get at. I almost did..... 

Once the slave cylinder work was complete, I started on the master clinder. Before starting on the master cyl replacement, remove the lower part of the fascia (four screws) like I didn't. You can see the fluid union here, it's quite hard to get at.

Unlike 99.99% of quattro owners, mine has an "access panel" over the master cylinder. Which makes getting at the cylinder compartively easy. Once the union is undone, there are 2 bolts to undo. If you look carefully at this, you can see that the master cylinder appears to have been replaced before, and incorrectly fitted, they had to use all the adjustment in the pushrod. The Clutch pedal needs to be "up" at this point to get access.

New Master cylinder now fitted.

Hose to Resevoir fitted.

Much easier to get at if the fascia is removed (that took me a while to realise. D'oh!)

Relay diagram on the rear of the fascia...


So next I reconnected the hydraulic pipe to the master cylinder, adjusted the mechanism pushrods to take up slack, refitted the access panel, and filled it up with fluid. Once the system was bled (several times), I had a useable Clutch! Job done....

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