I have a confusing issue on my '87 S4 n/a. It's been around the block a few times, who knows what prior owners have done to it.

The clutch, slave, and master cylinder are all new. The top ~2 inches of clutch pedal travel do nothing. I have to push the clutch pedal all the way to the floor to disengage. When I release it, the pedal comes up, but not all the way. I have to pop it up the last two inches.

I poked my head under the dash. During the first two inches of travel, it feels like the clutch pedal's rod isn't even pushing on the master cylinder piston; it's just loose and can rattle around. There's no more thread to lengthen the rod.

That doesn't make sense. Could it be the wrong rod, or maybe the wrong clutch pedal assembly? It looks like someone has monkeyed around with it in the past.

Any ideas? It shifts fine as long as I push the pedal all the way to the floor.

 

sometimes you can get it with adjustment under pedal box rod

BUT

the slaves for the turbo R box and the NA M box have different position mounting feet to suit different mounting positions on respective gearboxes

if you have a miss-match you need to make a custom throw rod
you take a long coach bolt and you turn the head down to a mushroom on a bench grinder ( similar profile to the end that fits the fork )
then you guessti-guage the extra couple of inches you need and shorten the bolt to suit
regrind a dome profile onto the bolt end to fit into the cup in the slave

refit
it should just fit with a few mm of free play so all the bolt threads line up on the lugs

you then adjust under the peddle to get 1 inch free drop at the pedal to ensure no riding, especially when the engine bay is hot

 

Is the clutch pedal cast aluminum and match the brake pedal?
RXs have rather distinctive pedal assemblies, it should be easy to tell if it's not original (highly unlikely anyway).

I'd try bleeding the system, could just be air in the master.

 

+1 sounds like air

 

Or find an old school RX "clutch slave" push-rod
OR find an old school RX clutch pedal push rod. They are longer than SA-FC.

 

If you have miss- matched **** then get the right ****.

Case closed.