Manual Transmission - Clutch reservoir fluid exchange..now pedal is worse...???




99ssleeper
06-16-2007, 08:53 AM
I read on here that someone had luck using a syringe to pull the old fluid out of the clutch reservoir...then pouring in new fluid...pumping the pedal...and repeating a few times. I did that about 10 times and the fluid did come out pretty dark at first, now it's fairly clear, much better than it was.

Now the problem is when I go through the gears hard, the pedal will stick to the floor. At other times it feels fine but will then have a low pedal or feel spongy for a minute...but then after pumping it a few times will go back to normal. It never stuck to the floor before I did the fluid exchange.

I also realize that there is probably still old fluid down at the slave cylinder, but I would think that the fluid should mix and cycle through after some time.

Any ideas? My guess is a some air in the system, but I dont know how it would have gotten in there with the way I pulled the old fluid out.


Jontall
06-16-2007, 10:07 AM
I did the same thing and air entered the system. The only way to fix this is to crawl under the car and bleed it the old fashion way.

6']['9
06-16-2007, 10:16 AM
re-bleed it the old way. you can fill the resivoir with new fluid and bleed it from the trans. i read to pump the pedal then hold it down and open the bleeder valve, tighten and start pumping again. What did was pumped it a couple of times then opened the bleeder valve then pushed down the pedal that way you push out all the air and the fluid at the same time. either way just keep doin it till you go through about half a bottle of fluid or til the fluid from the trans comes out fresh instead of black.


black01_WS6
06-16-2007, 10:50 AM
do you have the drill mod done?

to get some of the extra air out you can use a mityvac from autozone. Very simple to use.

99ssleeper
06-16-2007, 11:40 AM
no drill mod. i will do that when a new clutch goes in...not worth the work right now.

Ranger
06-16-2007, 08:21 PM
Hundreds and hundreds of Corvette owners have keep the fluid fresh via the reservoir. I've followed it for Six years and 500 passes with a normal clutch pedal.

If the fluid has not been kept fresh throughout a car's life, it will often take 10-20 changes of the reservoir with 20 pedal pumps between to get the fluid back to the nominal boiling point on the can. The slave can be significantly junked up with residual sludge, being the lowest element in the closed system, the sump. That is the one rationale for the 20 fast pedal pumps...to agitate the fluid and help dislodge accumulated deposits in the slave. That agitation doesn't occur on a simple full bleed.

Please state what brand and DOT# you used and what color the fluid is now. If it contains any murkiness , it's still below the boiling point spec. Suggest you stay with it.

I've never, never, never had nor seen a single issue of "air" somehow getting into the hydraulics via the reservoir. Can't happen. The reservoir is the highpoint of a close system. Gavity does the rest.

Ranger

99ssleeper
06-17-2007, 04:03 AM
I used Pyroil DOT3...did about 7-8 exchanges. Tonight I ran it through 3rd gear hard and the pedal stuck to the floor, had to pull it up with my foot. It didnt stick right away though, it was still fine after I put it in neutral and coasted down...then when i pushed the clutch in to engage a gear it stuck. The clutch would still release but the pedal would not move more than 1-2" off the floor.

Ranger
06-17-2007, 04:31 AM
I used Pyroil DOT3...did about 7-8 exchanges. Tonight I ran it through 3rd gear hard and the pedal stuck to the floor, had to pull it up with my foot. It didnt stick right away though, it was still fine after I put it in neutral and coasted down...then when i pushed the clutch in to engage a gear it stuck. The clutch would still release but the pedal would not move more than 1-2" off the floor.

Thanks. And what color is the fluid now? If there is any murkiness at all, the fluid is still compromised. I'd suggest continuing with the protocol until the fluid stays completely clear after 20 pedal pushes. Then check the clutch.

If you've never changed the fluid before now, your clutch actuator (slave) needs to have enough fresh fluid put through it and agitated to get the slave clean and free of residue.

This protocol almost always works. So it's worth trying. Other paths are more intrusive and expensive.

Ranger

black01_WS6
06-17-2007, 04:18 PM
I went the more expensive route and just changed out everything. But at 100k I thought it was good maintence.

berger21
06-18-2007, 10:17 AM
Thanks. And what color is the fluid now? If there is any murkiness at all, the fluid is still compromised. I'd suggest continuing with the protocol until the fluid stays completely clear after 20 pedal pushes. Then check the clutch.

If you've never changed the fluid before now, your clutch actuator (slave) needs to have enough fresh fluid put through it and agitated to get the slave clean and free of residue.

This protocol almost always works. So it's worth trying. Other paths are more intrusive and expensive.

Ranger

Is there a brand of fluid that works best?

Ranger
06-18-2007, 10:26 AM
Is there a brand of fluid that works best?

There are many choices. You can't go wrong with the GM-branded fluid recommended in your owners manual.

At the midpoint of this page ( Taking Care of Your Clutch ( http://www.rangeracceleration.com/Clutch_Care.html) ) is a link to a very good list of alternative brake fluids (eg clutch fluid).

I've settled on Prestone Synthetic. Used DOT3 in the 2001 and 2002 LS6 clutches; using DOT4 in the 2006 LS7 clutch. Any fluid will require frequent changes if the car is driven aggressively.

Ranger