On this Saab,  It has a telescoping slave cyl.  It is squeaking.  Is there a type oil or grease that is ok to spray on hydraulics?  I have sprayed brake fluid on the out side and it quiets.  after a while it starts squeaking again.  SC

Is it the cylinder its self that is squeaking or is it whatever it is pushing?  If it's the actual cylinder, I'd think it would need to be replaced.  If it's not the cylinder, I'd try some spray with white lithium grease at the point of the squeak . . . or maybe teflon spray lube.

On this Saab,  It has a telescoping slave cyl.  It is squeaking.  Is there a type oil or grease that is ok to spray on hydraulics?  I have sprayed brake fluid on the out side and it quiets.  after a while it starts squeaking again.  SC

Brake fuid = bad for paint and rubber belows on telescoping arm.
X3 on what Zen said.
Also on my mom's S-10 I took off the slave cyl and used a socket extension and screw jack to push the clutch past where the slave had been wanting to go.
I have to do this about once every 3-4 yrs in that the grime builds up to a point that the Slave cylinder has a hard time over coming the resistance.
Once the clutch is engaged back past the memory of the sludge, it gives the slave cylinder an easier time of it.
If I do not do this she will blow the slave cyl.
I do not know why it has to be done, I just know it works and slave cyl are expensive.
KC