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Exactly how to bleed a clutch? by 87gt guy
Started on: 07-26-2002 09:12 PM
Replies: 6
Last post by: 87gt guy on 07-27-2002 01:14 PM
87gt guy
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Report this Post07-26-2002 09:12 PM Click Here to See the Profile for 87gt guySend a Private Message to 87gt guyDirect Link to This Post
How do you bleed the clutch? I have no clutch at all. I did have to pump it for a while, now I have nothing.
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ED's85GT
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Report this Post07-26-2002 09:59 PM Click Here to See the Profile for ED's85GTSend a Private Message to ED's85GTDirect Link to This Post
Look in v8-archie's website, I used his procedure and it worked for me.
good luck, Ed
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Archie
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Report this Post07-26-2002 10:11 PM Click Here to See the Profile for ArchieClick Here to visit Archie's HomePageSend a Private Message to ArchieDirect Link to This Post
 
quote
Originally posted by 87gt guy:
How do you bleed the clutch? I have no clutch at all. I did have to pump it for a while, now I have nothing.

Proper Clutch Bleeding Archism #4 "Forget what the manuals tell you".

Clutch bleeding prodeedure

You can do it your way, But this method always works for me.

After checking to be sure there are no leaks in the Clutch Hydraulic system.

Complete ALL of the following steps before test driving the car:

1) Install a helper in the drivers seat to push in and let out the clutch pedal on command.

2) Remove the cover from the Master Cylinder reservoir.

3) Top off fluid in the reservoir.

4) During the course of this procedure DO NOT allow the "helper" to "pump" the pedal. The "helper" is to depress and release
the pedal on command only, DO NOT PUMP THE PEDAL. (See theory below)

5) You will be opening and closing the bleed screw on the slave cylinder as instructed below. CAUTION: During this
procedure protect your eyes from squirting brake fluid.

6) (Helper) Press clutch pedal in fully and hold.

7) (You) Open the bleed screw to allow fluid to escape.

8) (You) Close bleed screw.

9) (Helper) Release pedal completely

10) (You) Top off fluid in reservoir.

11) Repeat steps #6 thru #10 no less than 5 times before going to #12 below. NO PUMPING!

12) You have now bled the Master Cylinder and the hydraulic line. YOU ARE NOT DONE YET!!!!! We must now bleed the
Slave cylinder. (This is what the manual doesn’t tell you)

13) With no further action to be done with the clutch pedal, you can no remove the "helper" from the drivers seat and have him
(her/it) help you do the following.

14) After topping off the Master Cylinder, completely remove the bleed screw from the slave cylinder.

15) Have the "helper" stand at the ready with the bleed screw and the appropriate wrench for installing the bleed screw.

16) PROTECT YOUR EYES!

17) With the bleed screw removed. With both hands grab the push rod coming out of the slave cylinder and push it into the
slave cylinder as far as it will go AND HOLD it in.

18) Your "helper" will now install and tighten the bleed screw while you hold the plunger in.

19) When bleed screw is tight release the rod and as it comes out guide it into the proper position on the clutch arm.

20) Top off the Reservoir and the job is complete.

Theory:

Why do I insist that you REMOVE the bleed screw when pushing the plunger in on the slave cylinder? This is simple hydraulics.
Fluid or air will always go the direction of least resistance. When you are pushing the rod into the slave cylinder you will find
that it is impossible to push it in at a slowly and steadily pace. If you push it in too fast with the bleed screw still in and just
unscrewed a few turns some of the brake fluid and/or air in the slave cylinder will go back up the hydraulic line that you just
bled, thus necessating your starting over.

When bleeding your clutch....The biggest mistake or miss-conception a person can make is to pump the pedal.

The clutch Hyd. system, unlike the brake Hyd. system SHOULD NOT BE PUMPED. The only thing that happens when you
"pump" the clutch is that you make any large air bubbles in the hydraulic system into a bunch of small air bubbles. BTW these
small air bubbles are harder to bleed out than larger bubbles.

You cannot "pump up" a clutch. If you have to "pump up" the clutch to make a shift then you have a leak and you can bleed the
system a dozen times to no avail.

On the clutch, think about it now, if you could "pump-up" the clutch wouldn't the T.O. Bearing tend to invert the clutch
diaphragm and travel toward the engine until it met up with something solid like the flywheel. On a braking system, when you
"pump-up" the brakes you force the brake pads into the rotor until the line pressure builds up enough that the resistance you feel
when pumping the pedal increases. Further, as you press harder and harder on the brake pedal the pads just increase their
pressure on the rotors.

GM Thought this through when they designed the system. To avoid "pumping up" the clutch hyd. system, GM put in a small
bleed back hole in the master cylinder. (BTW not an original idea, all Hyd. clutches have it) This bleed back hole relieves line
pressure every time the pedal is at the top of the stroke. Didn't you notice when you "pumped up" the clutch pedal that it
doesn’t firm-up like the brake pedal does?

The only thing you accomplish when "pumping up" the clutch pedal is to take any air bubbles that are in the system and atomize
them into smaller air bubbles, thus making the problem worse. Remember when you were at the soda shop, as a kid, and your
parents kept giving you hell about playing with you soda and straw? Same theory here! The more you move that soda through
the straw the smaller the air bubbles become.

BTW the "hand pumps" work ok but I’ve never needed to buy one yet. With the hand pumps you still need to ensure that the
slave cylinder gets completely bled.

v8archie

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Ron_Dundee
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Report this Post07-26-2002 11:14 PM Click Here to See the Profile for Ron_DundeeSend a Private Message to Ron_DundeeDirect Link to This Post
Fiero Clutch and Brake bleeding!
A One Man Job!
Made Easy....even on the Fiero clutch!!!

This is long winded, but really a couple of easy steps.

It'll cost you a one time investment of $40.

Many parts stores sell these cheap looking manual vacuum pumps for just this kind of job. It comes with some tubing and a cheap plastic in-line reservior. It looks like a hand exercise gym thingy with a little gizmo sitting on top.

As cheap as it looks, it's well worth the investment. It actually isn't that cheaply made either. It just appears to be at first sight. I've used mine over a dozen times on my vehicles so far, and it still operates like new.

Basically it works like this. I'll use the Fiero clutch as the example. With the car on flat ground...

Remove the black float and old fluid in clutch reservoir, wipe it out til it's clean, and refill with new DOT-3 fluid. Leave the black float out for now.

Go in back to the slave cylinder and place a rag under it. Remove the bleeder valve, and clean it. Make sure air will pass through the tiny hole. A pin cleans them out well if dirt got inside.

Wrap a number of windings of Teflon tape around the threads of the valve and screw it into the slave cylinder. Make sure it covers only the threads and not the valve seat. The purpose of the tape is to minimize air leakage, and maximize vaccuum. Teflon tape is used for pipe threads, and is extremely good for high temp applications.

Attach the hose from the hand vac pump and suck out fluid until the fluid coming through the hose looks clean. Be certian to watch how much fluid you are drawing out, as you don't want to completely drain the reservoir up front. The pump's reservoir has measurements to assist you how much fluid you pulled through the system. You will need to stop pumping and refill the master cylinder at least two times.

Don't get discouraged when you see a lot of air bubbles in the plastic tube. 99.99% of the air being sucked out is actually air getting past the Teflon tape. Just keep going until you feel confident the fluid coming out is clean.

Once you think you're done, close the bleeder valve "While The Pump Is Still Drawing Fluid". This assures no air got into the system from the open valve.

Adjust the fluid level up front and don't forget that black float. You're Done!

The Teflon tape also makes it easier to open the bleeder valve years down the road.

Now if you want to do the job "Even" easier, have an assistant keep the master cylinder full of DOT-3 so you don't have to stop to refill.

I've had great success with Fiero clutch perforance using this method.

Doing the brakes is just as easy. Just start from the farthest wheel from the Master Cylinder, working to the next farthest etc.

It's a one man job for sure. No pumping a clutch or brake pedal.

I understand that many ABS brake systems require this method, so if you think you're going to save the $40, you may just end up getting it for one of your other cars.


------------------
Ron Dittmer - Driving A Mint 88GT, Automatic, Medium Red Metallic, Gray Interior, Black Lace Wheels, With Sunroof and Wing, in the Chicago area.

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cunninghamsean
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Report this Post07-27-2002 05:30 AM Click Here to See the Profile for cunninghamseanSend a Private Message to cunninghamseanDirect Link to This Post
Archie's way works great. Ron's way should work also as long as you do not create an air pocket by sucking fluid away from the push rod. The vac thing may have enough suck to pull the rod back but I have found that pulling it back by hand ensures no air. If you were to put the vac on and pull the rod back and tighten the valve all at the same time that would be great but you may need to grow another hand.

Sean

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fierotom
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Report this Post07-27-2002 09:13 AM Click Here to See the Profile for fierotomSend a Private Message to fierotomDirect Link to This Post
Hi all,
archie's way works very good for me. The problem is the helper. Now I have the MityVac One Man Bleeder, it works great !!!
No problem with helper and it is easy and
fast. Complete clutch bleeding takes only 10 minutes.
greetings from Germany
Thomas
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87gt guy
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Report this Post07-27-2002 01:14 PM Click Here to See the Profile for 87gt guySend a Private Message to 87gt guyDirect Link to This Post
Man, you guys are awesome. I am going to do that later today. My friend has one of the vacume pumps. I know I probably have a leak somewhere, but I just need to get the car away from where it is right now so I can work no it later. What do you think my problem could be, slave cylender, or master? I do seem to get full pressure once in a while (normally after shifting 2nd into 3rd) but then I would loose the pressure? Or, if I have a leak, how can I detect where it is coming from?
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