Clutch fluid

[jimmers]

I want to flush my tranny out and have 2 questions. How much fluid does the tranny hold so i know how much to buy. I was told that i can just use dot 3 brake fluid in it, is that correct?

i have a 6 speed by the way.

 

[froggy47]

Do you mean flush/bleed your clutch master & slave?

 

[JEFNLSA]

If it's clutch fluid you are after, I'd use the GM Hydraulic Clutch Fluid #12345347. One bottle should be more than enough.

For any/all info on the ZF 6speed (including fluid recommendations) go to www.zfdoc.com.

 

[jimmers]

well i went to a GM dealer to get the clutch fluid and they told me to just use dot 3 brake fluid. He said they didnt even have the Hydraulic Clutch Fluid #12345347. Does anyone exactly how many litres of it i need? All they sell are little bottles of dot 3 fluid.

 

[froggy47]

well i went to a GM dealer to get the clutch fluid and they told me to just use dot 3 brake fluid. He said they didnt even have the Hydraulic Clutch Fluid #12345347. Does anyone exactly how many litres of it i need? All they sell are little bottles of dot 3 fluid.

I WAS able to get the 12345347 from Superior Chevy, I think it was about a 20 oz bottle, more than enough unless you have new/dry master & slave. Then I'd probably have a 2nd bottle on hand just to be sure in case you have trouble with bleeding the slave..

DOT3 is ok, might squeak. I've heard squeaky clutch pedals on some cars, drive you nuts.

 

[NC2Stay]

Jimmers, it sounds like you are mixing up replacing the clutch fluid with the transmission fluid - not the same thing, not at all. The clutch is separate, and uses hydraulic fluid, doesn't use very much. The transmission itself is filled with something more like oil - there are lots of posts about it, and its quite a bit more volume.

Bob

 

[CAJUN C4]

I want to flush my tranny out and have 2 questions. How much fluid does the tranny hold so i know how much to buy. I was told that i can just use dot 3 brake fluid in it, is that correct?

i have a 6 speed by the way.

Use Valvoline Synpower..It's the Best !

 

[c4cruiser]

If the GM clutch hydraulic fluid is not available, a good DOT3 brake fluid will work. It would be a good idea to flush the system of the old fluid if you are going to use brake fluid as a replacement.

The clutch hydraulic line does not see the heat like that generated by braking so wet or dry temp values for the brake fluid are not as important.

 

[jimmers]

How do you flush it out exactly? is it similar to bleeding the brakes?

 

[WhalePirot]

Yes, but the slave must be rotated 45° to get all the air out of it.

 

[-=Iron Mike=-]

Are you doing tranny fluid or your clutch line? Both are easy but use very different fluids.

 

[jimmers]

im doing clutch fluid.

 

[-=Iron Mike=-]

Use either a DOT3 or DOT4 brake fluid. I use Valvoline Synpower DOT 4. The slave cylinders are actually self bleeding and if you remove the top of the master and slowly depress the clutch pedal you should see bubbles rising from the line if air is in fact trapped and the slave is working properly. Just make sure the car is on level ground.

Is something not working right or do you just feel the need to flush the system?

BTW, I saw your post over at CF but didn't see the need to type this twice on two different forums.

 

[jimmers]

well usually that forum has answers alot quicker....

 

[WhalePirot]

The slave cylinders are actually self bleeding

They weren't in the early C4s. Did that change in a certain model year?

 

[froggy47]

The slave cylinders are actually self bleeding and if you remove the top of the master and slowly depress the clutch pedal you should see bubbles rising from the line if air is in fact trapped and the slave is working properly. Just make sure the car is on level ground.

News to me

You might get "some" bubbles out, but if they are truly self bleeding, there has been a huge hoax played on thousands of c4 Corvette owners since 1989.

Bleeding the Clutch Hydraulic System:
There are two versions ('89-'90, '91-'96) of clutch hydraulic Actuators (slave cylinder) for the C4 Corvette. The '89-'90 Clutch Hydraulic System actuator has the feed tube located at 12 o'clock and bleed tube at 10 o'clock. The '91 - '96 Clutch Hydraulic System Actuator has the feed tube located at 12 o'clock and bleed tube at 6 o'clock. This redesign makes the bleed fitting more accessible. Unfortunately, the bleeder horn repositioned to the 6 o'clock position complicates the bleed process due to the fact that air bubbles rise therefore rendering the reverse bleed method as being most effective approach to bleeding the system. Reverse bleeding is the process of forcing fluid into the system at the lowest point forcing the fluid back and upwards to the master cylinder fluid reservoir. This method will only be successful if no air is allowed to enter into the system during bleeding. WARNING: When pressure bleeding any hydraulic system it is necessary to provide the best seal possible around the bleeder fitting threads so as not to inadvertently draw in air as fluid is being pumped into the system. To achieve this affect, remove, clean and carefully apply 3 to 4 wraps of Teflon tape to the thread area only of the bleeder screw. Failure to follow this procedure will result in an improperly bled hydraulic system due to air ingestion during the bleeding process. NOTE: The best method that I have found so far in reverse bleeding these types of systems is to bleed the system until the fluid is clean and void of air bubbles, tighten bleeder screw, cycle the clutch pedal 50 times at varying rates and stroke depths, then perform one additional bleed before securing the tightening the bleeder screw to 18 Nm (13 lbs. ft.). Although bleeding can be done more simply by opening the Actuator bleeder and letting gravity draw fluid through the system, the following bleeding method will provide a more thorough evacuation of old fluid and particle accumulations.

'89-'90 Clutch Hydraulic System: The vehicle must be level front-to-back and left-to-right can be from level on up to 2 feet higher than the right side. The bleeding process is most effectively done by conventional method where one person actuates the clutch pedal while another opens and closes the bleeder after the pedal is depressed to the floor and before the pedal is let back up. After the bleeding process is complete, fill the reservoir to 1/16" below the "Low" mark so that when the "clean and dry" moisture barrier is re-inserted and lid screwed on, the fluid level remains between the LOW and HI mark. This set up method provides the best level of atmospheric pressure isolation with in the hydraulic system.

'91-'96 Clutch Hydraulic System: The vehicle must be in a level position both front-to-back and left-to-right when bleeding. The bleeding process is best done with a pressure bleeding system such as a "Phoenix Injector" or "Mighty-Vac". Bleeding of the system is best done by reverse flowing clean/new fluid, feeding the Actuator bleed horn located at the 6 o'clock position. Reverse pressure bleeding pushes the used fluid back upwards from the Actuator bleeder through the system on up to the reservoir. After the bleeding process is complete, fill the reservoir to 1/16" below the "Low" mark so that when the "clean and dry" moisture barrier is re-inserted and lid screwed on, the fluid level remains between the LOW and HI mark. This set up method provides the best atmospheric pressure isolation of the hydraulic system. WARNING: When pressure bleeding any hydraulic system it is necessary to provide the best seal possible around the bleeder fitting threads so as not to inadvertently draw in air as fluid is being pumped into the system. To achieve this affect, remove, clean and carefully apply 3 to 4 wraps of Teflon tape to the thread area only of the bleeder screw. Failure to follow this procedure will result in an improperly bled hydraulic system due to air ingestion during the bleeding process. NOTE: The best method that I have found so far in reverse bleeding these types of systems is to bleed the system until the fluid is clean and void of air bubbles, tighten bleeder screw, cycle the clutch pedal 50 times at varying rates and stroke depths, then perform one additional bleed before securing the tightening the bleeder screw to 18 Nm (13 lbs. ft.). Although bleeding can be done more simply by opening the Actuator bleeder and letting gravity draw fluid through the system, the following bleeding method will provide a more thorough evacuation of old fluid and particle accumulations.


www.zfdoc.com

Check doc's web site.

 

[-=Iron Mike=-]

Yep. Contrary to the repair manuals, the '89-96 slaves are self bleeding. I honeslty have no idea why the writers of the repair manuals want to make the job seem difficult, because its not.

Over the last two years I've had a bit of a slave cylinder soap opera going on. You may have read that others were having problems with GM's replacement slaves? I was one of those guys. :crazy

 

[jimmers]

thanksf froggy47 that was a great help!!