Clutch Hydraulic Flush & Fluid

[muskiemike]

Hello,

I was told that one should periodically flush and replace the hydraulic fluid in the clutch (4- Speed).

My question is, if you flush & replace the Brake fluid, does this automatically flush the hydraulic fluid in the clutch?

Or are the independent of each other?

 

[JonM]

You have a MC for the clutch and one for the brake system...The one for your brakes is on the booster with TWO caps on it. The MC for the clutch is under the booster and to the left with one cap. In order to bleed the clutch, you need to remove the slave cylinder on the bell housing and tilt it 90 degrees open the bleed screw while someone presses the clutch peddle in then tighten it up.

 

[LarryBible]

They are completely independent of each other. Look on the firewall behind and to the left of the brake cylinder for the clutch cylinder. It has a round black cap about 1 1/2" or 2" in diameter.

Check the rubber flex line at the slave cylinder closely before flushing. This line is right next to the catalytic converter, so the heat causes it to fail prematurely(great engineering huh?)

If you let the system get totally empty it can be tough to get the air out, so to flush, suck out what you can from the reservoir, fill the reservoir with fresh fluid, get a helper to press the pedal then crack open the bleed screw and flush a little fluid out. Have the helper let off the pedal, then press it again for another squirt. Make sure you don't let the reservoir run out of fluid and repeat the flushing process until you are getting nice clean fluid coming out of the bleed screw.

Good luck,

 

[JonM]

http://www.parts123.com/parts123/yb.dll?parta~showpic~0000050f~02365~~

 

[muskiemike]

THX to ALL your Replies!

You guys are great - no Absolutely GREAT!

THX for all of your replies, I took the car in and the Brakes and the Clutch Hydraulic fluids flushed and changed.

Since the car is a 84' with only 30K miles the brake and clutch fliuds have never been flushed.

The shop said that unless the fluid is burndt, or has water in it, they should last for 100 years.

The brake fliud was dark and dirty, and I had it flushed and filled with fresh oil.

The Clutch fluid was down about 2 onces, and the mechanic, said just add to it, but I had him flush it and add new fluid anyways.

Here's the concern:

After he did it, when I tried to get the 4speed into reverse, the gears ground a bit, he bleed it some more, still kinda ground into reverse, then he said I need to put into to push in the clutch, put it in another forward gear, then into to reverse, as the the reverse does not have syncro, this worked, but I don't recall having to go through this effort before.

Any comments?

 

[JonM]

That is preposterous, you shouldn’t have to shift into another gear to get reverse. Did he remove the slave cylinder like I mentioned above to bleed it? Also you have a 4 speed + 3…make sure you change the fluid and filter (ecklers has them) in the +3 part. This is very important and should be done every 10,000 miles. The +3 part uses automatic transmission fluid. The other part of the transmission uses 90 differential oil, and should be topped off. What does your car idle at …if its idling to fast it could cause a grind in the shift.

 

[vigman]

Not bled correctly Clutch slave

The NOSE of the clutch slave is HIGHER then the bleeder valve when the slave is installed.

Air gets trapped in the NOSE of the slave cylinder.. and you wind up with not enough pedal.

The GRIND is the clutch not FULLY disengaging... when you put it in to a FWD gear..in reality you are STOPPING the input shaft fropm turning... then with a quick shift into reverse.. you do not grind.. but that is a band-aid if your stuck one night.

I'll bet you do not have the "Normal" amount of pedal now.. and the clutch disengages ONLY when your MASHING the pedal down.

Here's the trick.

1) Loosen, quickly the bleeder then just get it snug, so it will be easier to undo when the slave is unbolted from the side of the Bell housing.

2) Remove the linkage rod from the slave to the clutch fork.

3) Grab the slave cylinder & point the bleeder valve UP and the nose
( piston side) of the slave DOWN.

4) Bleed normally.... but do not keep the master resevoir full... keep it 1/2 to 3/4 full.
(NOTE the piston will move all the way FWD to the C clip.)

5)Re install the slave & linkage.. as you push the rod into the nose of the slave.. it will back fill the resevoir back up

6) Check pedal travel & grind factor...OK?

7)Top off rez, lube the shift linkage.

8) Enjoy the ride~



Vig!

 

[vigman]

And Brake fluid WILL NOT LAST 100 YEARS

That is a silly statement!
Brake fluid ATTRACTS moisture!
As it gets BROWNER it is suspending MORE water... and increases it's boiling point.

If it boils you get a spongy pedal.

I change mine every 2 years!



Vig!

 

[muskiemike]

Hey VIG and JonM - THX

Sounds like you guys no what you are talking about.

The owner of the transmission shop also said, that as I drive it the clutch pressure will return - this sounded pretty lame to me . . .

But heck, he is the mechanic not me (but it's my car)!

I just tried to call to take it back to the transmission shop, but they close at noon on Saturdays, so, I'll have to wait until Monday.

You guys are right, the clutch pedal seems "real" flat, and when I turned the car off for a few hours and pushed the clutch in to restart, the clutch seemed REAL, REAL soft.

Is there any harm running it like this until Monday, or should I just wait until Monday to take the car back in?

 

[muskiemike]

Hey VIG and JonM - THX

THX!

 

[vigman]

Do you do your own wrenching?

We could talk you thru it....

I wouldn't drive it unless you HAD to!


Vig!

 

[muskiemike]

Hey Vig,

Not on the vet, I have a 75 Harley and do some work on it, and restored a 1903 "Curved-Dash" Olds - send me your e-mail and and I'll send you a picture of the Olds - it's pretty cool!

Vig, thanks again for help, as you can tell I do not wrench the vet.
And I am a novice regarding the 350 CFI engine.

You guys appear to be experts!

 

[muskiemike]

Hey Vig

THX for your comment to help me through it, but it's only me here, and sounds like it takes two to get it right.

Now that you and JonM give me the "correct" way to do it, I'll take it back to the transmission shop and have them turn the slave upside and bleed it, as well as follow your guys detailed instructions.

I must say, I am REALLY, REALLY impressed the working knowledge of this board - this is most technical board I have come across.

 

[vigman]

BURRRRRPPPPPPP

What.... huh technical... heck yesterday I couldn't even spell tecknical!


LOL

Vig!

( It's really not that hard )

 

[muskiemike]

Hey Vig

Well, I hang around these boards long enough I'll get technical in a hurry.

I am gonna' take it back to the transmission shop on Monday, with your and JonM's directions in hand, I am sure this will resolve the problem.

P.S. here's that old olds I been restoring!

 

[JonM]

Let me give you a little bit more advice. If you plan on keeping an 18 year old Corvette around, and your budget is limited. (That means you’re not a rich guy) (Who knows with the Harley and Vetts...you could be Jay Leno) You will have to learn about fixing it, or at least have some understanding as to what you are paying for...Go to this site and buy the manual and electrical supplement for your car. It is PRICELESS...It will cost you about 60 bucks #ST36484
http://www.helminc.com/helm/homepage.asp?r=

 

[muskiemike]

Problem Fixed

THX to all for your support, the problem is now fixed, VIG and JonM - special THX to, your were right on the money to solve the problem . . .

Again, "THX!

 

[ddmau]

Just a point of information, when I first purchased my '85 I sometimes had the problem of grinding going into reverse. When the long awaited owners manual finally arrived I read where they recommend going into a forward gear first. Works every time.

 

[muskiemike]

Final Summary

Hello,

While it has been recommended that one flush and change (R&R) the DOT 3 fluild from you master / slave clutch cylinders on occasion - I have a 1984 vet, 4+3 Manual with 30K original miles.

I have had the car since 1985, and I never did a R&R on the clutch.

So, after 18 years, I figured perhaps it should be done.

Well, a word of caution to those who are contemplating a similar excercise.

After having the trans shop do it, and after 3 return trips to the trans shop, and the last trip was on a flatbed trailer, you need to seriously consider performing this maintenance prior to doing so.

I have heard all about how DOT 3 will attract mositure and debris, but both the Chevy Service Mgr and Trans Shop were somewhat reluctant to perform the R&R since I was not having a clutch problem - their recommendation, just make sure it is not leaking and add DOT3 when needed.

Summary, as a result of the shop performing the R&R, the new DOT3 apparently disturbed or ate away some of the seals in the master clutch cylinder and therefore it was leaking and allowing air into the system. I lost all pressure of the clutch pedal and could not put it into any gear - ultimately I had it towed on a flatbed to the Trans Shop, and I had the Master and Slave Clutch Cylinders replaced.

All for the nominal cost of $485 . . .

While I have to admit the clutch feels a strong as it rolled of the show-room floor, just a word to the wise should you be faced with a similar situation.

Good luck to all and Happy Thanksgiving!

 

[Vrotate]

Fluid Change

My Clutch fluid ate out the o rings in the clutch master cylinder, and started squirting fluid on my feet! I had to rebuilt it...

The Car had 60,000 miles on it. So change fluid often!

Vrotate