5MT clutch feels soft during hot weather/long drives

[Huffer]

5MT clutch feels soft during hot weather/long drives.

Basically, when I start the car the pedal feels normal - ie. high point engagement. As I drive, especially in hot weather, the pedal gets softer and I can actually push quite close to the floor before the clutch disengages. Does this mean the hydraulic fluid or hoses are expanding too much?

Any solutions or causes I should look for?

[Reason]

I dont think that much, but it could be a combination of that and fluids are more, well "fluid" in the heat. How old is the clutch fluid? I would flush it with some new stuff and go from there. Roger I also have a SS clutch line that will help with the pedal feel regardless. PM me if interested for the price on it.

[afterbangin]

I bet you need a new slave cylinder or yours is slowly on the way out. The symptoms you describe are classic with the Subaru TSB for replacing the slave and hydraulic line. Most of the time you don't need to replace the line, just the slave cylinder but you want to make sure you bleed it properly to get a firm return on the clutch pedal back to the top. If you don't deal with it, you may get to the point where your clutch stay engaged and you can't get it out of gear. I personally had this happen to me and I almost ran my car into the garage door. After replacing the slave, the car felt a million times better and yes, I only experienced the symptoms you are writing of when it was really hot out.

[Huffer]

^^ thanks for the tip - do you have reference to the TSB?

[Huffer]

I think I found it:
http://www.automd.com/tsb/bulletin_b139274/



1998 Subaru Legacy Power Train Service Bulletin 139274

NHTSA: Action Number: 10001726 Service Bulletin Number: 139274

Report Date:
May 19, 2003
Component:
Power Train


Summary: Clutch pedal sticking. *tt

[Bookem]

Mine was doing same thing, slave cylinder fixed it and never had any symptoms since.

[Huffer]

So do you guys reckon I should just buy a new clutch slaved cylinder, and replace the clutch fluid then, or try bleeding the old fluid first?

[mike-tracy]

Bleeding the hydro system properly is a huge PIA when the system is dry. There could be air trapped in your slave cylinder. What I did that worked was depressed the slave cylinder's piston several times, which shoots fluid (and possibly microscopic bubbles) back into the reservoir, then slowly returns. Drove it for a day and repeated a few more times. Pedal feels fantastic now.

Subaru's design is kind of crap for the slave cylinder in that it traps air easily and is hardish to bleed due to how low the bleeder screw is in relation to the master cyl.

[decke48]

Happen to me before. Bleeding it fixed it for a short time. But the problem would return. Replaced the slave fixed it and havent had problem since.

[chuckthefuk]

Seen this happen several times and the after-market units would constantly fail over a 4-6 month period. OEM units are worth the money!

[Huffer]

Well I just ordered a new clutch slave. That thing is expensive for a little piston.

[chuckthefuk]

where did you purchase the slave from?

[Huffer]

Sorry forgot to answer - I got mine from RockAuto.com - it's a Sachs branded part, $30 or so, but much cheaper than the factory part @ $90.
I have other Sachs hydraulic parts, and they've worked fine so I'm willing to give this a shot. Rockauto is great at returns and processing so I'm not worried.

[98OBW]

Keeping an eye on this thread...

I replaced the slave, master, and line on my car - and now I have the problem randomly when the car is cold and it just gets worse when it's warm. Sometimes can't get the car into gear when it's warm and I need to downshift, other times it's fine, and most of the time the clutch engages/disengages right on the floor and sticks down there.

When this first happened I replaced the slave, then the line, then the master, and no change replacing anything - even after bleeding a whole quart of fluid through the system. I'm curious to know if this fixes your problem, as I think we ordered the same slave from RA (although I got my line from the Subaru dealer).

[Huffer]

No worries. I still haven't had a chance to install yet. Hopefully next week.