Im going to change my c5's clutch fluid as its looking a little dark (black actually) I read these instructions http://forums.corvetteforum.com/show....php?t=1464336
and it looks like a strait forward job. being a C5 I'll using Dot 3 fluid of course. I have some Prestone DOT 3 synthetic brake fluid. the filler cap only says "USE DOT 3 FLUID", will the above work and be safe for the clutch system? I know in some resevours regular vs syntheic does make a difference. I don't know if the stock stuff is synthetic or not. I have a 99, will the Prestone Synthetic DOT 3 be good?

 

Hmmm....cruised through a lot of that information but didn't find anything about bleeding the entire system. I would think that just refilling the reservoir doesn't refresh the fluid in the slave cylinder. I have a '98 chev pickup with a five speed and was starting to have shifting problems. Figured it was time for a new clutch and T/O bearing etc. Well, I looked at my clutch master cylinder and the fluid was black. I opened up the bleeder at the T/O bearing/slave cylinder (it's all one unit) and started dumping fresh fluid through. I let gravity do it's thing. Lo and behold, the fluid started clearing up, I closed the system and the clutch and shifting have been fine since.

Without looking yet, I'm assuming my Vette has a similar bleed system at the slave. I would think if you just fill the reservoir the fluid at the slave is the same crappy stuff you started with. Doesn't do any real good to replenish the entire system and improve the seals in the slave.

Am I wrong??

Maybe should check in the tech forum....

 

I wouldn't mix synthetic w/ regular clutch fluid...I used this procedure and it helps shifting...

 

whichever you use, don't put the extra fluid back on your shelf. the fluid has a 24 hour shelf life and cannot be used after 24 hours of the bottle being opened due to moisture absorbtion. it is also recomended to NOT remove the cap on the reservoir to check the fluid level. use a flashlight so see through the reservoir to check it for the same moisture absorbing reasons.

 

Do a search for Ranger's procedure on clutch bleeding. I used the GM Clutch Fluid. It's pretty easy, cover everything good around it with towels, and some use a turkey baster like, I used a Mighty-Vac and suck out the fluid. With very clean lint free towels wipe the inside of the cylinder clean. Refill. Close Top. Pump clutch pedal about 20 times or so. Repeat until the fluid remains clear. Takes about 3 times if it's pretty dark now.

 

I would use Valvoline Syn-Power and yes Ranger's technique works very well. I changed the reservoir ~20 times and it remains crystal clear now. After the first 10 you could actually see the mushroom cloud of dirt come up from the tube while the clutch was being cycled.

As for the 24 hour, that has been mentioned before and I am calling on that due to the fact that you pour it in an open environment I might agree to do so on a low humidity day but I have keept brake fluid containers previously opened on the shelf with no adverse affect. Just my opinion.

 

I've never heard that either. I put mine on the shelf. Close the cap tightly.

 

and I only use Valvoline Syn-Power in everything I own, best stuff I have ever used.

 

For my '01 with 46K mi. that was probably never changed before it took around 20 changes of the reservoir to get it to stay pretty clean. It seems now I can keep it clean if I'll just change it once every 3 or 4 weeks. The car is not raced or abused. I've been using Valvoline synthetic.

 

sounds like I'll be doing this a couple of times at least. any more on problems with the synthetic vs whatever is in there right now? if you guys switched to Synthetic chances are that fluid and whatever came stock were mixed for a while in between. I should have gone with the valvoline it sounds like, maybe I'll go pick some up, save the Prestone for another car or something.

 

 

I've heard the suggestion of short shelf life brake fluid for years. I've never figured out how to get it out of the sealed bottle or into the reservoir w/o letting some air in.
Maybe the same people who suggest that oil still needs to be changed every 3,000 miles also own stock in brake fluid companies. Seriously, I understand the water absorption concept, but it might be sometimes blown out of proportion.
I recently decided to refresh the brake fluid in my 5,800 mile Z16. I had no clutch problems, but the fluid was just starting to become more amber than clear. I used Ranger's method. I "cleaned" out the system with DOT3 regular brake fluid about five times and pumped the clutch pedal in between maybe 50 times. It stayed clear...so, I sucked out the clean regular brake fluid (PRESTONE) and replaced it with DOT3 synthetic of the same manufacturer.
I can't say that I've noticed any significant change in shifting, but then I didn't have any complaints to begin with. I've driven the car about 150 miles of varied driving since and it's still clear.
Since I had the partially full "open" bottle of brake fluid, I decided to refresh my brake reservoir as well. The engine bay looks better with clean reservoirs.

 

HI There,
I changed mine in the summer. The original fluid was in my 01 & dark looking in the master cyclinder.
I used GM clutch fluid p/n 12345347. I used a turkey baster & sucked it out that way. I put a lot of rags around because the baster will leak a little as you pull it out. Have a container right close by the master cylinder to drain the fluid into.(Cut the top off a 1 gal. milk container) Clutch or brake fluid will take the paint right off.A favor injector sold at w. mart is better & no leakage. Only thing after you empty the master cylinder the first time the fluid cracks the plastic & the injector is no good any more. Any way I drove the car & then the next day repeated the same procedure. I think I did this about 10 times as to use the entire bottle of fresh clutch fluid up.There was a oz. or 2 left I just threw out the bottle. If the weather is bad like here in central pa. & you don't want to take the car out. Service the m/cylinder install the boot & cap & pump the pedal 20 times then use the turkey baster & repeat the process.
When its completed fill with fluid even with the first step inside the m/c. When you are holding a light near the m/cylinder you will clearly see the black boot inside the m/cylinder with out removing the cap.BTW thats the proper way to check the fluid not by removing the cap. Any clutch or brake fluid thats been sitting around throw out & use fresh, then throw that container out when you are finished.You will notice a smoother shifting transmission after you do this & no dark fluid will return. If it turns dark after a period of time , install a new boot.
robsc501

 

I cleaned out my master cylinder the other day. The fluid was black and there was also black gunk in the bottom.
Does anybody know how you bleed the whole system?
Is there a bleed valve underneath?
Is the clutch directly behind the motor or in front of the gearbox?