Clutch Master Fluid Change - How Often ???

**Mecinoid** · 09-28-2007, 12:41 AM

How often do you guys change the fluid in your master cylinder for your clutch? I seem to change mine every 20K or so. It's brown to black every time and as soon as I change it the trans shifts so much better. I'm sure it's because I drag the car and the fluid get really hot. I went to synthetic this time around so maybe I'll get 40K out of it.

Let have it how often do you change your fluid and what color is it now?

**NJ2002WS.6** · 09-28-2007, 04:01 PM

I don't have an answer, but I have a similar problem. When I push down my clutch it sticks to the floor. The car starts, but I can't put it in gear. I checked the fluid and it was bone dry. I poored fluid in and it filled right away (when I figured it would take a lot). I don't know if there is a clog or what. I don't know if my cltuch is burnt out...AHHHH please help!

**Wesman** · 09-28-2007, 06:26 PM

Originally Posted by NJ2002WS.6

I don't have an answer, but I have a similar problem. When I push down my clutch it sticks to the floor. The car starts, but I can't put it in gear. I checked the fluid and it was bone dry. I poored fluid in and it filled right away (when I figured it would take a lot). I don't know if there is a clog or what. I don't know if my cltuch is burnt out...AHHHH please help!

Ummm...if you had no fluid in the master cylinder reservoir, you need to bleed the system. Once air is introduced into the system, it will not function properly until its been bled of all air. There should be a bleeder valve down by the hydraulic fitting on the side of the transmission.

**Mecinoid** · 09-28-2007, 10:08 PM

Originally Posted by NJ2002WS.6

I don't have an answer, but I have a similar problem. When I push down my clutch it sticks to the floor. The car starts, but I can't put it in gear. I checked the fluid and it was bone dry. I poored fluid in and it filled right away (when I figured it would take a lot). I don't know if there is a clog or what. I don't know if my cltuch is burnt out...AHHHH please help!

Looks like you might have a leak and once you fix the leak you'll have to bleed it. If you haven't before it's best to take it to a job shop. They have to power bleed it or elevate the car to 30 degs for gravity bleed. The shop should only charge about $80 to fix the leak fill and bleed the system.

I have mine drained, filled and power bleed about every three years and I do not put a lot of miles on mine. But, when I drive my clutch get hot drag racing. I used Motul HiTemp fluid last time and it still starts to turn brown after 20K miles.
Only at the track ... but as many times as I can make it in a year. I do drive hard so, every three years or 30K would be what I'd recommend for the normal driver.

**JonB** · 09-30-2007, 04:48 PM

This is Straight from gm, the recomended fluid change is in bold and underlined.

"The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:
Some customers may comment about an intermittent spongy clutch pedal feel or clutch pedal sticking to the floor. This may be aggravated by aggressive driving and high clutch operating temperatures. Higher than expected levels of water in the clutch fluid greater than 2% may cause the clutch fluid to boil. The presence of water in the fluid lowers the boiling point significantly; when these conditions are present the driver may lose customary clutch pedal feel and performance.

Recommendation/Instructions:
If the above condition is intermittent flush the hydraulic system using DOT 4 fluid part number 88958860 (88901244 in Canada), prior to replacement of any mechanical or hydraulic components.

To eliminate the opportunity for moisture to enter the clutch hydraulic system.

The clutch fluid level inspection should be a VISUAL inspection only. Look through the transparent reservoir and observe the fluid level. Avoid removing the cap. Do not remove the cap just to top-off clutch fluid. Leave the system closed and sealed. During PDI inspection or routine servicing the cap should not be opened for just an inspection.
DOT 4 clutch fluid has a 2 week shelf life. Do not use fluid if container opening date is unknown or older than 2 weeks. Do not mix or re-use old fluid. Current service information already covers the issue of reuse.
To provide the best clutch operation, it is recommended that the owner change the clutch fluid every 2 calendar years. Please flush and replace the clutch fluid with P/N 88958860 (88901244 in Canada) or equivalent DOT 4.
The current service information and owners manual will be updated to reflect this information.

Note: If the concern is not intermittent, inspect clutch hydraulic system for leaks and repair as necessary after repairs are completed flush system with DOT 4 fluid part number 88958860 (88901244 in Canada).

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed."

Ok now every 2 years is rediclous along with gm's recomendation on plug and wire change at 100,000. If your fluid is getting dark and dirty at 20k you need to change it more often, try 10k if its dirty then try 5k ect. Fluid condition has alot to do with how you personally drive. For an old grandma that drives an m6 and never gets over 3k and is easy on the car every 2 years would probably be fine. For most of us in the performance world and drive our cars hard I find every 2 years ridiculous and is part of the reason there are so many issues with the gm hydrolics IMO. The key to keeping the hydrolics working properly is keeping the fluid fresh and clean. To anyone that has dark nasty clutch fluid they should do a full bleed then once you get all fresh new fluid, at what ever interval you find works best for your situation just change out the fluid in the resivoir. If you keep with that then every year or two do a full bleed of the system.