Question: Moisture in Clutch Fluid

[DrNavyRet]

During the heat of the summer, my clutch woked perfectly. With the past two weeks of freezing weather, my clutch pedal sticks to the floor after start up and a shift into any one gear. Pumping the clutch pedal and warming up the engine and, like magic, the problem disappears. So my theory is that there is a small amount of ?water? in my clutch fluid. Is there anything that I can put in the master cylinder to safely eliminate the moisture? Or am I all "wet" with my shade tree diagnosis? Thanks in advance for your assist.
The Old Retired Sailor

 

[hcbph]

Clutch

Have you ever heard of something comparable that would work with the brakes under a similar condition? Neither have I. The clutch is nothing more than a small portion of the brake system. You have a master cylinder, hydraulic line and a actuating cylinder (slave).
Having said that, I'm a little skeptical that it's frozen moisture in the line. It sounds to be cold related but not necessarily internal related to the fluid. I think it's somewhere in the master cylinder area especially if the pedal is sticking to the floor. Have you tried pulling up on the pedal and see if it will release if pulled up? That's what I would try first. Master cylinders can go bad, linkage rods can be bent just to name a couple of items.

 

[DrNavyRet]

I have toed up the pedal to start the "pumping" action. Incidentally, I have thought about the master cylinder as the source of the problem, but the car is a 2004 and has under 10K, easy miles on the odometer; I ruled out the MC because of the low usage as well as the fact that in the warmer months, the problem does not show up.

 

[hcbph]

Misc

I wouldn't necessarily rule out anything. I have a T-bird with an analog speedometer what every time the temp falls down near or below freezing the speedometer no longer works.
Warm it up and it's fine. That's just the way it is. If it was a safety thing I'd fix it but as it is, it's just a nuisance at times.

 

[Vettehead Mikey]

I have toed up the pedal to start the "pumping" action. Incidentally, I have thought about the master cylinder as the source of the problem, but the car is a 2004 and has under 10K, easy miles on the odometer; I ruled out the MC because of the low usage as well as the fact that in the warmer months, the problem does not show up.

So change the fluid.............

 

[Toms007]

Changing the fluid is pretty easy and it sounds like you are a classic example of a victim. The symptoms you describe are classic examples of nasty clutch fluid. I've seen fluid from cars with less than 10k on the clock where the fluid was black as coal.

Here's the write up I did on my C6.

C6 Technical and Performance - Corvette Action Center - Corvette Forum : CorvetteActionCenter.com Corvette Forums

 

[DrNavyRet]

I did the modified Ranger method and changed the fluid several months ago as I did a search on the various forums regarding the "sticky clutch pedal." Checked the fluid now and it is still clear. Using the Ranger Method to change out the fluid, how many times should I drain and fill the MC body since I don't have a "dirt bowl" to use as a reference point to stop?

 

[gmjunkie]

The Ranger method works good for periodic maintenance,But you'll never get all the sludge out that way!

It''s allot better to flush it out the bottom the conventional way,as the plumbers say......."Sh*t won't run up hill"!:L

 

[DrNavyRet]

The Ranger method works good for periodic maintenance,But you'll never get all the sludge out that way!

It''s allot better to flush it out the bottom the conventional way,as the plumbers say......."Sh*t won't run up hill"!:L

OK. Now "out the bottom" means at the slave cylinder? What do I have to remove to get to that point? A half hour job becomes a major effort? Or do you have a simple way to do the job? Teach me. Thanks in advance.

 

[Toms007]

I think that it means from the clutch. I think there is a "bleeder" down on the bellhousing. Just like bleeding the brakes. Please correct me if I'm wrong Junkie.

 

[DrNavyRet]

I think that it means from the clutch. I think there is a "bleeder" down on the bellhousing. Just like bleeding the brakes. Please correct me if I'm wrong Junkie.

Before I put the Vette up on the jack stands, I believe that I read that there are numerous bolts and other "pieces" that needs to be removed to get at the slave cylinder and the bleeder. I think that I remember guys saying that's why they installed a remote bleeder so that they would not have to disassemble the bottom of their car again. Am I correct? Or is there an easier procedure?

 

[LLC5]

Before I put the Vette up on the jack stands, I believe that I read that there are numerous bolts and other "pieces" that needs to be removed to get at the slave cylinder and the bleeder. I think that I remember guys saying that's why they installed a remote bleeder so that they would not have to disassemble the bottom of their car again. Am I correct? Or is there an easier procedure?

You are correct, and it is the only way to properly bleed and flush the clutch fluid.

Changing the clutch reservoir fluid basically does nothing....except change the reservoir fluid.

 

[DrNavyRet]

You are correct, and it is the only way to properly bleed and flush the clutch fluid.

Changing the clutch reservoir fluid basically does nothing....except change the reservoir fluid.

Thanks for the reply as it confirms that I am not an Alzheimer's patient as yet in that I remembered what I read months ago. I still have the same question - why does the problem go away after warming up the engine? Bleeding the clutch should not be a 6 hour job; what was Chevy thinking for all the years of the C5 production?

 

[LLC5]

��
Thanks for the reply as it confirms that I am not an Alzheimer's patient as yet�� in that I remembered what I read months ago. I still have the same question - why does the problem go away after warming up the engine? Bleeding the clutch should not be a 6 hour job; what was Chevy thinking for all the years of the C5 production?

I don't think that warming up the engine is making the problem go away, it is probably pumping or using the clutch pedal that makes the clutch pedal feel normal. It could be either a clutch master cylinder or the slave cylinder going bad, but pressure bleeding the system is the first place to start. Good luck with it.

 

[Hib Halverson]

I think that it means from the clutch. I think there is a "bleeder" down on the bellhousing. Just like bleeding the brakes. Please correct me if I'm wrong Junkie.

You can only wish it was that easy.

There is a bleeder on the concentric clutch slave, but you need to remove the exhaust center section and the tunnel close-out plate to gain access to it.

Also there is a difference between "bleeding"–which expells any air trapped in the clutch hydraulic system–and "flushing"–which replaces the existing fluid and any contamination with new fluid.

While you might be able to "bleed" the system without actually using the bleeder on the concentric slave, you can only "flush" the system by opening the bleeder on the slave and letting fluid flow until it runs clean.

 

[Gdad45]

Fluid is black and gooey in the reservoir. I'm thinking it's the old crappy fluid that's absorbed moisture. It does happen to brake systems and rusts from the inside out.
My clutch is fine when the weather is warm, but not when below freezing. Do you suppose the moisture is freezing right at the cylinder orifices?


Since it's so difficult to bleed / purge old fluid, I suspect mine has NEVER been changed in 15 years and 73,000 miles.

It's in the garage waiting to go up on stands for a full purge and refill.

Wish me luck and warm weather.

 

[Hib Halverson]

The black and gooey is a slurry of rubber particles (from the clutch hydraulics' interior) and the fluid.

Flush the system and most of it will go away.

Best to flush the clutch every 3 years...which reminds me. I need to do my C5, too.