I've never changed the clutch fluid.

Stock shifter. When the engine is off it shifts into every gear very smoothly. Also, when it was intermittent it shifted smoothly.

Rick

 

Just went back to reread your original post and saw this.... That is not a good sign.. something is causing the clutch not to disengage fully.
a simple test to see if its air in the line.. is to pump it.

My 1st dealer clutch replacement they never properly bled the clutch.. As I left the dealer the pedal went to the floor and barely disengaged..

I had to double and triple pump the clutch pedal to get the car back to the dealer for them to fix it..

If it starts to creep at a light and you pump the pedal a few times.. Does it make the problem go away for a little bit?

Either way it can be just about anything from the master to the slave... Also the stock Luk clutch has some sort of adjustment mechanism built into it..supposedly automatically to adjust for surface wear.. Maybe that is malfunctioning..

 

Tonight went out to replace the clutch fluid via Ranger's "dilution" process. FWIW, the fluid didn't look that bad after even 58k miles.

Drained reservoir and filled with fresh fluid. Very aggressively pumped the clutch 30 times however, there was no "action" in the reservoir. Tried pumping slow and fast and every combination in between. NO circulation of fluid.

I would think it would bubble, gurgle and spit like a brake reservoir does when bleeding. I had the reservoir cover on at first afraid it might "spit" out and make a mess. I then had my son pump the hell out of the clutch with the cover off while I observed the reservoir to see what was happening. No a ripple...

Shouldn't I have seen some "action" in the reservoir?

Doesn't this point to the master? Seems to me like the piston seals in the master have an issue? Ranger's step 2 is to replace the master........

Your thoughts

TIA.

Rick

 

I would recommend you follow the Service Manual steps I listed in post #3 ......

You seem convinced that there is no air in the system, so the next step (step #4 in my post) is to remove and tear down the clutch master cylinder ..... or simply replace it if you don't want to tear it apart.

If that doesn't solve the problem, then the work level rises dramatically, as you have to basically drop the rear end (differential and transmission) from the car, along with the drive train (torque tube) to access the slave cylinder.

Hopefully the problem is in the Master .... the Slave is a PITA to get to ...

Sorry I don't have an "easier" answer, but it seems to me it is time to attack the problem ....

 

An aggressively pumped pedal will aspirate clutch fluid all over the engine bay, if the reservoir cover is off. I learned that just once, the hard way. That assumes the hydraulics are generating normal flow when the pedal is actuated. Your results indicate a likely failure in the hydraulics.

I'd suggest moving to step-2 (installation of a fresh master cylinder) and then circle back to step-1 (another attempt to clean the accumulated goo from the actuator/slave) before moving to swap the actuator/slave and other clutch elements.

Ranger

 

I will follow your advice and TRY to bleed the system as my next step. Just not sure how the hell I'll get that done considering the location of the slave bleed. From what I read on here it is inaccessible.

I still don't understand how enough air could have all of a sudden entered my closed system to cause a problem of this magnitude. However, I appreciate and respect your advice and will follow it.

If this doesn't get it I'll replace the master. I figure if it's not the master and I have to go into the slave and clutch I'd replace it anyway as a maintenance item. I have nothing to lose. If it solves the problem great. If not I'd replace it anyway if I'm going to have to tear the rest of the system apart......

Rick

 

I did the Turkey baster method a few times.. Don't recall seeing any ripple... You'd be surprised at just how LITTLE fluid is being moved by one full pedal stroke..

2 Tablespoons...

http://forums.corvetteforum.com/show....php?t=1763721

 

If the reservoir had an adequate level of fluid in it when you first checked it, then it is unlikely you have air in the system. More likely the master or slave aren't functioning properly, especially as you noted that pumping the clutch pedal seemed to have no effect in the reservoir.

I hate to say it, but IMHO it is time to see if rebuilding/replacing the clutch master cylinder solves the problem, and that will require bleeding the system. If that doesn't fix the issue ... you're down to the slave cylinder and/or clutch causing the problem.

I totally agree with you when you say ...

"I figure if it's not the master and I have to go into the slave and clutch I'd replace it anyway as a maintenance item. I have nothing to lose. If it solves the problem great. If not I'd replace it anyway if I'm going to have to tear the rest of the system apart......"

If you have to do this much work, I'd replace all "wear" parts while I was in there (clutch plate, slave, etc.) so you don't have to do this again for a LONG time ... if ever again ...


Best of luck, the hydraulic system for the clutch is theoretically pretty simple, it is accessing the parts that is a complete PITA ....

 

Chuckster,

I previously read your thread, however, as Ranger points out pumping a pedal on a hydraulic system like the clutch or brake tends to make a hell of a mess if the cover is off. Take my word for it, been there done that. I surely should see something happening at the reservoir.

At this point I'm thinking either air in the system or a nonfunctioning master.

Maybe just wishful thinking on my part.........

Rick

 

Just curious how you made out here Rick?

Cause I had the chance to go out to the garage and pump my clutch wildly with the cover off..

So once again.. Ranger and I are getting different results.. I pulled the Master cover and had my son watch the fluid as I pumped the pedal to the firewall and up as fast as my foot could pump.. My son said..nothing.. zip..nada.. maybe a tiny disturbance from the car shaking from me pumping..

But certainly NOT the Old Faithful Geyser we are told to expect.. So whos car is broke or malfunctioning? mine or Rangers?

Just my .02

BTW,
My entire clutch, master and slave are brand new and have only 2000 miles at best..

 

Went out to bleed it tonight. Can't even see the bleed screw. Can't get my hand up there to even feel the damn thing. Great design work on the part of the General.

So, it didn't get bled. I bought a new master in case the bleed didn't work. For the hell of it I put the new master on. No luck..... Same problem. I have the same reservoir action as you describe with the new cylinder, basically none.

I don't know how anybody can get on that bleed screw. I'm afraid I might have to resort to professional help. Not happy, car is parked.

Rick

 

I Bled mine and the space is so tight it's insane.. my hand barely fit with the wrench.. Still ended up with Air.. and I was pissed..

so I tried the Mighty Vac way..and it worked great..

YOu need to make sure you push the Vac nozzle snug into the orifice at the bottom of the Master Resevior.. If you have ANY air you will see it after you establish a good vacuum...

Document ID# 1870200
2005 Chevrolet Corvette


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Subject: Info - Improved Bleeding Procedure for Hydraulic Clutch Release System #01-07-31-002B - (11/01/2006)



Models: 2007 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn)

2007 and Prior Chevrolet and GMC 6-7F T-Series Medium Duty Tilt Cab Models

2007 and Prior Isuzu F-Series Medium Duty Tilt Cab Models

2006-2007 HUMMER H3




--------------------------------------------------------------------------------

This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 01-07-31-002A (Section 07 -- Transmission/Transaxle).


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This bulletin is being issued to inform dealers of an improved procedure to aid in the ease of bleeding the clutch hydraulic system for the above listed vehicles. This procedure can be used anytime air is introduced into the hydraulic system. Following this procedure may also reduce the number of unnecessary parts replaced for low clutch pedal reserve and high shift effort.

Verify that all the lines and fittings are dry and secure.
Clean the dirt and grease from the reservoir cap in order to ensure that no foreign substances enter the system.
Remove the reservoir cap.
Fill the reservoir to the proper level with the required fluid.
Attach the J 43485 (Adapter) to the J 35555 (Mity Vac), or equivalent.
Important: Brake fluid will deteriorate the rubber on J 43485. Use a clean shop cloth to wipe away the fluid after each use.

Place and hold the adapter on the reservoir filler neck to ensure a tight fit. In some cases, the adapter will fit into the reservoir opening.
Apply a vacuum of 51-68 kPa (15-20 hg) and remove the adapter.
Refill the reservoir to the proper level.
Repeat Steps 6 and 7.
If needed, refill the reservoir and continue to pull a vacuum until no more bubbles can be seen in the reservoir or until the fluid level no longer drops.
Caution: The vehicle will move if started in gear before the Actuator Cylinder is refilled and operational. Start the vehicle the first time in neutral to help prevent personal injury from vehicle movement and see if the transmission will shift easily into gear.

Pump the clutch pedal until firm (to refill actuator cylinder).
Add additional fluid if needed.
Test drive vehicle to ensure proper operation.


GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION


© Copyright General Motors Corporation. All Rights Reserved.


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Document ID# 1870200
2005 Chevrolet Corvette

and do a bleed that way.. I

 

Charlie,

Thanks a bunch for your post. I've been searching for that procedure for a couple hours. Couple questions please:

1. Procedure states, "Place and hold the adapter (i.e., J 43485) on the reservoir filler neck to ensure a tight fit. In some cases, the adapter will fit into the reservoir opening".

What does this adapter look like? Could I just use a rubber "chemistry beaker" stopper that seals the top of the reservoir in place of the reservoir cap? It sounds like this is what the procedure calls for as it says, "on the reservoir neck".

Another post I read says to use a tappered "nozzel" that fits down into the small outlet hole in the bottom of the reservoir.

It would be much easier to use a stopper in place of the reservoir cap. A tappered nozzel through the fluid would be messy and a pain in the *** and probably suck more fluid than air.

2. Procedure states, "Apply a vacuum of 51-68 kPa (15-20 hg) and remove the adapter". How long do I hold it or will the vacuum just bleed down in a matter of seconds.

3. Also states, "Refill the reservoir to the proper level". I'm confused here. I take it the goal is to "suck" air out of the system. WHere is fluid going, or being drawn from, requiring me to refill the reservoir?!?!?! Is it going into the mity-vac?

If I use a "stopper" in the neck of the reservoir my vacuum source is not in contact with any fluid so how with I be evacuating/drawing fluid from the system?

If it would be easier to talk me through my confusion I sure would appreciate a phone call ANYTIME tomorrow, a.m or p.m. I'm at (918) 630-4544.

Your assistance is greatly appreciated.

 

Bleeder looks like this.



You would need to drop exhaust and tunnel plate to reach it. The top one is the bleeder.

I installed a remote bleeder.

 

Think I answered my own question regarding adapter J 43485. Googled J 43485 and saw a picture. It looks as I thought, basically a rubber lab "beaker" stopper with a hole through it.

Did the top bleed as detailed above in the GM procedure. No luck..... Pulled 20" Hg and didn't see any bubbles or lowering of fluid level. NO CHANGE at all with the problem.

I tried it several didn't ways. Repeatedly pulling the vacuum on the system while static (i.e., pull, release, pull, release, pull, release, etc). Then aggressively pumping the clutch with the vacuum applied. Also with a vacuum applied static for 30 minutes. No improvement of the clutch.

As I mentioned earlier some people draw the vacuum by inserting a nozzel directly into the small reservoir outlet orifice. I did not do this. I can't see how this would make a difference as a vacuum on the system is a vacuum on the system?

Looks like I'm going to have to tear it down.....

Rick

 

Try this test to see if the Slave is experiencing Leak Down..

Press the clutch all the way to the firewall.. Then start the car and put it in gear.. Keep the pedal on the firewall for at least minutes.. If the car starts to creep on you.. you pretty much nailed a leakdown.. It will suck cause EVERYTHING needs to come out for that..

Sorry I was not able to call.. Just logged in..

 

No problem on the call, I figured it out.

I can't do the test as you stated as I can't start it and then put it in gear. Won't go into gear w/engine running. Putting it in gear and then starting works and the car does creep, clutch not disengaging.

Rick

 

Then you have it narrowed down to the hydraulics.

Could try the quick fix and just replace the master as that may be your problem.

Pretty quick and easy to do. Just jack up the front left wheel and remove the wheel.

Remove the inner rear fender skirt (7MM) nuts.

Pull the center console and knee bolster.

Disconnect the rod inside the clutch pedal and remove from pin.

Remove the quick disconnect (tool is available for local parts store).

Give it a quick twist and do the revers to install it.

 

Thanks for the reply, however, master has been replaced as detailed in Post #31 above. Easy 30 minute job but did nothing to help the problem.

For what it's worth, it's easier to replace the master as per the service manual instructions. Take 2 nuts off the windshield washer reservoir and pull the reservoir. No need to remove wheel or inner fender skirt. Also, the quick connect was easy to separate without the "tool". Got it with just one flat screwdriver.

Rick

 

Rick before going for a tear down.. the stock Clutch has a Self Adjusting Pressure plate.. It adjusts itself for wear during its lifespan.. While it's supposed to be SELF adjusting.. sort of like the way rear brake shoes have that self adjustment... sometimes it does not work..

Maybe for some reason the adjustment got out of whack.. There is some procedure to manually adust it in the service manual. You need to pop the clutch inspection access cover off the bell housing do it..

I am certain if you can look in there you should be able to see exactly what is happening when the clutch pedal is depressed to the floor..

I did a search and so far this is the procedure I found..

1. Raise and suitably support the vehicle.
2. Remove the engine flywheel inspection cover retaining bolts.
3. Remove the engine flywheel inspection cover.
4. Have an assistant press in the pedal until tension is released from the clutch pressure plate stepped adjusting ring, then continue to hold the pedal.
5. Hold 2 screwdrivers or other suitable tools, and place them against 2 of the 3 stepped adjusting ring tension spring stops, just ahead of the adjusting ring tension springs. (The 3 slots are located at the center of the p/p)
6. Using the screwdrivers, rotate the stepped adjusting ring counterclockwise (compressing the tension springs) until the adjusting ring steps are fully adjusted out, then continue to hold in position.
7. Have your assistant release the clutch pedal.
8. Release the adjusting ring tension spring stops.


here is a picture of the access