Master Clutch Cylinder Problem 05 Forester?

[fetak24]

Sorry if there is already a thread on this.  I am new to this site.  I have a 2005 Forester X with 166,000 miles on it.  I recently had the head gasket replaced and while they were at it, I had them replace the clutch, timing belt etc.  About a month later, I was driving and the clutch pedal lost all pressure except at the bottom 1/8th.  The clutch still engaged and disengaged and I was able to drive it to work, but there was a very short excursion in which it engaged and disengaged.  The rest of the way the pedal was very loose.  That was yesterday. 

 

I read on a forum somewhere to pump it for a few minutes.  Did that and left it overnight and it was fine the this morning.  After driving for a bit, it became loose again, I pumped it, it tightened halfway, went out again and then firmed up again.  When I brought it to the shop half way through the day and they said the clutch master cylinder might be going out, but did not listen very well to the symptoms and I am suspicious of them due to the history of this past repair, which has not been good.  I would like to keep the vehicle but do not want to keep dumping hundreds of dollars into it if it would be better just to get a new one.  Help!  Does it sound like a master clutch cylinder problem?  Or something else?

 

Thanks!

[Fairtax4me]

Typically this type of issue is caused by the slave cylinder on the transmission.

Check the fluid level in the reservoir. If its low you have a leak, and the source will be your problem cylinder.

Here is a rubber dust boot on each cylinder where the pushrod enters the cylinder. Pull the boot back and see of there is fluid inside it, if there is fluid the cylinder seal is leaking and that cylinder needs to be replaced.

[fetak24]

The fluid level is at the max line, so no apparent leak.  I wasn't able to check the boot tonight, but will do so in the coming days.  Does this point to the master cylinder?  If so, does it usually go out quickly or gradually?

[unibrook]

My 2001 Forester slave seals went bad 3 yrs ago at about 110k miles.  The symptom was mushy pedal pressure when the engine was HOT in the summer.  So, I figured that because of where the slave is located on top of the engine, and the symptom was heat related, that would be the most likely culprit.  And it was.  Now the pedal works for about 3 strokes, before sinking all the way to the floor, and it doesn't matter if the car is cold or warm.  So, this time, I am suspecting the master cylinder as culprit.  There was no loss of fluid and no visible leak last time or this time.  Stay tuned!

 

UPDATE:  136k miles on her now.  Turns out this time, that I have a pinhole leak in my black rubber clutch hose--connects the Slave banjo bolt to the bracket connecting to the metal line that runs to the Master cylinder.  Here are some notes of advice for trouble shooting I came up with:

 

Do not assume that just because the fluid level LOOKS full from outside the reservoir on the
Master, that it really is full.  That might just be a darkened bathtub ring film coating the inside of the reservoir
near the Full line, fooling you into thinking there is fluid inside.  Instead, BE SURE to open the reservoir cap and look inside to check the fluid level.  If low, pour in more DOT3 fluid and bleed the system until you get some clutch pedal pressure and functionality.  If it seems to continue to suck down fluid
and the pedal return does not seem strong, then you must have a leak.  Remove the big plastic airfilter box to gain
a better view of the whole clutch hydraulic system.  Wipe down all components and clutch lines
with a clean rag.  Then have your partner continue to pump the clutch pedal, while you top up the reservoir with
fluid.  As your partner presses down on the clutch, she is putting pressure into the system, this is when any leaking
fluid must be spraying out somewhere…either from a component or the metal line or
rubber hose.  Look for the wet spot!

Edited September 13, 2015 by unibrook

[forester2002s]

Another way to test for a leaking master-cylinder:

- Car on level-ground;

- All brakes off;

- Engine idling;

- Clutch-pedal to the floor and hold it there;

- Engage 1st gear;

- Keep the pedal to the floor, & wait;

- Wait some more;

- If the car starts to move forward (pedal still to the floor), then the master-cylinder is leaking internally.