[IanT54]

Certainly sounds like a slave cylinder problem.

"My thoughts: slave cylinder is gone, leaking fluid onto the clutch, allowing slippage when forced into reverse, but grabbing enough to move the car backwards."

Do you have the clutch pedal pressed down when you're doing this?

Any sign of leakage under the car after leaving it overnight?

 

[BobGSaab]

No signs of leakage; yes, pedal was down when putting into reverse.

 

[net48734]

I just had this same scenario and was indeed the slave cylinder gone bad. Mine had went to the floor and had very little clutch left and a whole lot of play. I didnt have enough clutch to even make it go in reverse and didnt want to screw anything else up by grinding gears. Since I didnt want to pay to have it towed to a mechanic I used the old method of putting a stick or something long enough to hold the pedal to the floor and opened up the brake cap and let it sit overnight. Cover the brake cap with something just to not get dirt in it and let it sit open overnight with the clutch all the way to the floor. I know this doesnt work for all, but for me when I put the brake cap back on and removed the piece of metal holding the clutch to the floor I had enough clutch left to drive it to the mechanic where it was a $750 bill to repair the slave cylinder. Hope that helps.

 

[BobGSaab]

Thanks. My pedal isn't staying on the floor, but otherwise sounds very similar.

Just trying to get an idea of what parts I'll need before tackling this.

 

[IanT54]

Just trying to get an idea of what parts I'll need before tackling this.

Slave cylinder
Clutch disk and pressure plate (if it hasn't been replaced recently)
Main oil seal (if it hasn't been replaced recently)

Some people like to resurface the flywheel as well.

 

[BobGSaab]

Is the main oil seal a tough job? I definitely want to take care of things while I have it apart.

I was planning on the clutch disc, pressure plate, slave cylinder, master cylinder (while the system is open, they're not that expensive); and then putting in some better mounts to firm everything up while I'm under there.

Thanks again for the response.

 

[earthworm]

Its the master cylinder with an internal leak.
Save your leg strength, the slave is moving just a little if at all.
Saab had the same problem with hydraulic back in the 60s and 70s.
The master would leak internally and the slave externally...$10 to $20 was all it took for the slave and a bit more for the master.
The slave is intregated with the TO bearing, making its replacement an expensive operation.
Do check your fluid levels.