| | | quote | Originally posted by FIERO FARM:
Come on guys. I can't be the only one to have this problem. Help a guy out. |
|
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.
archie
Also read http://home.v8archie.com/arch6.htm & http://home.v8archie.com/arch7.htm
