Hi all,

 

I am in the process of replacing the slave clutch cylinder on my 98 outback (pedal-sticking-to-floor issue). I reassembled the system and could not get the system to bleed. Every push of the clutch pedal met with zero resistance and no fluid moving through the slave, just a little air. So, now I am wondering about the health of my master cylinder and was wondering if this is a valid test of the master:

 

I detached the metal tube that goes from the master to the rubber hose on the slave, topped off the master cylinder with brake fluid, screwed the plastic cap on tight and then pushed down on the clutch pedal. I expected a stream of fluid to come out of the bottom of the master cylinder when I did this, but again, pedal moved with zero resistance and no fluid came out of the cylinder.

 

So, have I determined that my master cylinder is bad? Or could this be due to a big, bad air bubble keeping the fluid from coming out?

 

Thanks in advance!

 

Kevin

Might as well just buy a new master cylinder. Uggh.

Bench bleed it or just disconnect the line at the cylinder and let it drip. Will take hours and you'll have the watch the MC so it doesn't run dry but eventually gravity will expell the air. Slave cylinders are almost always a pita to bleed.

Or borrow a friend for 30 minutes and have him get inside the car and pump clutch pedal to help you bleed the system.

Thanks for the comments. I disconnected the outlet pipe from the base of the cylinder, and two days later, no fluid has leaked out the hole. Weird...

Hi all,

 

I am in the process of replacing the slave clutch cylinder on my 98 outback (pedal-sticking-to-floor issue). I reassembled the system and could not get the system to bleed. Every push of the clutch pedal met with zero resistance and no fluid moving through the slave, just a little air. So, now I am wondering about the health of my master cylinder and was wondering if this is a valid test of the master:

 

I detached the metal tube that goes from the master to the rubber hose on the slave, topped off the clutch master cylinder with brake fluid, screwed the plastic cap on tight and then pushed down on the clutch pedal. I expected a stream of fluid to come out of the bottom of the master cylinder when I did this, but again, pedal moved with zero resistance and no fluid came out of the cylinder.

 

So, have I determined that my master cylinder is bad? Or could this be due to a big, bad air bubble keeping the fluid from coming out?

 

Thanks in advance!

 

Kevin

 

Hi.. I have the same issue.. I did the same thing that you did.. and had the same result.. now I am confuse if I have to buy a new one or not.. my last resort would be to take my car to a dealer but they always give me a high quote even for the simplest repair or check up..

 

How were you able to resolve this?

Bench bleed it or just disconnect the line at the cylinder and let it drip. Will take hours and you'll have the watch the MC so it doesn't run dry but eventually gravity will expell the air. Slave cylinders are almost always a pita to bleed.

 

+1. you can find other similar threads where folks (GD comes to mind from last year), that detail how difficult these things are to bleed.

 

GD found a precise method for bleeding...i just can't recall if that was for the slave or MC, but i would find his thread wrestling with this same issue. search for this and search for GD as an author.

If you aren't getting any fluid dripping through the hose even, something is wrong... Make sure there's some freeplay in the pedal. If the rod is pushing the piston in the cylinder when the pedal is up, it will close the ports and no fluid will get through.

I had this happen to me bleeding a new master cylinder on a VW beetle a few weeks ago...