01-28-2009, 05:41 PM
Join Date: Dec 2008
Location: Oregon for the last 14 years, before that in the military and all over the place
My Clutch Problems and How I Resolved Them
My clutch issues and how I resolved them:
External Clutch Slave Cylinder
First I’d like to say thank you to the forum in general. All of the previous threads concerning clutch problems, shifting problems, grinding gears, etc. were very helpful in the overall troubleshooting process. Without the folks here on the forum I’d have less cash in my pocket and wouldn’t have the satisfaction of doing the job myself. With that said, I’m publishing my own findings and adding my own experiences in hopes that future Jeepsters who need the same info will find it helpful. I’m no expert and I don’t claim to be one. There are often many ways to make repairs. The following is only my experience, what I encountered, and how I resolved it.
• The clutch pedal became increasingly hard to push in.
• The clutch had to be pushed farther and farther towards the floor in order to shift
• When pushing in the clutch pedal, it sounded like something was straining itself. I’d like to describe the sound but can’t and it might be misleading anyway so I’ll just leave it as straining.
• Intermittent problem going into and out of 1st gear or reverse
-- Physically hard to push from neutral to 1st
-- Physically hard to pull from 1st to neutral (popping out)
-- Sometimes impossible to go into reverse without grinding
-- Sometimes a slow grinding sound when going to reverse then it would stop and shifting into reverse would be normal
• The problem occurred frequently in temperatures below freezing or higher elevations. Not sure if it was temperature or pressure from the higher elevation or both that made it occur more.
• Checked the liquid level in the Clutch Master Cylinder to find it empty
• I later found the master cylinder has a boot of some sort that sits over the liquid and sometimes comes off with the cap. IF it does not come off with the cap, and stays in the cylinder, don’t be fooled like I was into thinking it was empty because the liquid reservoir is actually below this boot / gasket item. Later in my troubleshooting I was adding break fluid to what I thought was the reservoir but was not (don’t I feel stupid for wasting a couple hours of my time)
• The manual and forum said that if the liquid drops too low then air bubbles might be in the line. Since I thought the cylinder was empty, I proceeded to attempt bleeding the line of air bubbles.
Think about safety:
= Goggles or face shield
= Rubber gloves to keep the fluid off your hands
= Old clothes
= Plenty of ventilation so as not to breath too many vapors
= Lots of rags or paper towels
Lessons learned the hard way (mistakes):
o Found the slave cylinder by tracing the line down from the master cylinder. It’s mounted on the external of the clutch bell housing.
o On the top of the slave cylinder there was a set screw (Allen Head) that theoretically one would open enough to bleed the air out in a similar manner as bleed brake lines. HOWEVER, BLEEDING IN THIS MANNER IS NOT A GOOD IDEA!!!
o My helper pumped and then held the pedal on the floor while I turned the set screw with an Allen wrench. Both air and then liquid shot out the hole in the side and right onto my arm and face. BE SURE TO WEAR GOGGLES!!!
o We attempted another set of pump and hold and got liquid but the pedal became very weak, no resistance at all, no back pressure against the foot.
o I went to check the liquid level in the master cylinder and this time the boot / gasket thing came off with the cap! Now I could see the real reservoir and it was definitely empty.
o Filled the reservoir with brake fluid and reattempted the bleeding process. After multiple sets of pump, hold, release, the symptoms returned only back to where they were when I started the project (tension in the pedal went back to the old normal).
o On my last set, the plastic threads on the body of the cylinder started to shred. The set screw became unable to tighten, and it leaked profusely.
o Time to get a new part
Installation of the Slave Cylinder:
• Based on what I saw here on the forum, I decided the set screw way of bleeding air from the lines was NOT the way to go. I would suggest you don’t even try it because you not only risk getting sprayed in the face with brake fluid, but it will eventually ruin the threads and damage the plastic body of the slave cylinder. There is another way to bleed the cylinder which is explained later (press on cylinder and allow air bubbles to expel out of the master reservoir)
• Dismount the slave cylinder body from the bell housing and place over a bucket
• Remove the set screw from the cylinder (completely)
• Remove the master cylinder cap and the rubber boot / gasket thing
• Allow the liquid in the lines to drain from the cylinder into the bucket
• Remove the line from the back of the cylinder
-- Place a piece of wood between the floor and the front drive shaft so that you can use it to prop the cylinder against when hammering the pin out of the fitting which holds the tube in place
-- I tried using a small Phillips head, an Allen wrench, and other items but found a torx (star shaped) screw driver works the best. An appropriate sized nail punch would be best. You need to find something that does not go into the hole of the pin or it will cause the edges to flare out, preventing movement. Something flat headed is best.
-- Position the body of the cylinder against the wooden board, hold the body in the same hand as the pin pusher you choose to try, and gently tap the pin until it starts to move out of the hole.
-- Once you’ve got the pin started, then you can use any device to punch it out the rest of the way
-- If the old “O” ring stayed on the brass fitting, remove it and use the new one
-- Install the “O” ring onto the end of the brass fitting that remains inside the tube
-- Install the set screw into the bleed housing of the plastic cylinder: DO NOT OVER TIGHTEN!!!
Fill the cylinder with brake fluid
-- I was surprised at how much fluid you can put into the cylinder
-- Remove the plastic holders for the piston from their mounting position on the flange...DO NOT CUT OFF. We need the piston to travel through it’s full length without being limited by the holders.
-- Over a bucket...Move the piston in and out slowly while pouring liquid into the cylinder
-- Try to put as much liquid in as possible
-- With the cylinder pointing towards the ground, push the brass fitting (on the end of the tube) with the new “O” ring you just installed into the back of the new cylinder
-- Use your fingers to install the new pin enough so that it stays in the hole.
-- Lightly tap the pin the rest of the way in
BLEEDING AIR OUT:
Prop the cylinder against the board in a way that it stays oriented with the piston pointing towards the ground. Th next step will be to bleed the air bubbles and we want them to flow up out of the cylinder and up the line towards the master.
• Pour brake fluid into the master cylinder
• Manually press the piston on the slave cylinder and listen to the liquid moving through the tube. You should hear a combination of liquid being sucked down into the tube and air escaping back out through the master cylinder
• Check the level at the master cylinder, maintain about half full
• Slowly move the piston on the slave cylinder in/out until there is no more sound liquid moving into the lines or air bubbles leaving the line. An assistant might be helpful but not necessary. After about 10 in /out cycles it should be done.
• Place the rubber boot / gasket and cap back onto the master cylinder
• The bleeding is done. If you follow this procedure and your problems do not go away then you do not have to worry about the bleeding procedure. If your problems don’t go away then you either have a problem with the master cylinder, the clutch components inside the bell housing, or possibly a bad slave cylinder from the manufacturer (it happens).
• Check for leaks at the cylinder
• Mount the slave cylinder
-- Place the plastic tabs that limit the piston travel back into the holders so that the piston will only go out as far as the tabs allow
-- I’ve read that the tabs need to stay attached; however, my old cylinder did not have them. When I placed the new cylinder into the bell housing, I could tell that there was only about ¼ of an inch travel that would be allowed if I left the tabs installed. I removed them with a pair of dikes. You may want to consult others on this step and not take my advice. I thought I needed more than ¼ inch travel so off they came and it seems to work fine.
-- Be sure the end of the piston is resting in the correct place
-- Gently push the body of the cylinder towards the bell housing. The piston should retract.
o Install the two bolts
o Check for leaks
• Check to see if shifting improves with the vehicle off
• Check to see if shifting improves with the vehicle on
• Check for leaks
• Take a test drive
• ALL MY ABNORMAL SYMPTOMS WERE GONE and I got a refund on the master cylinder.
We only go around once....make it good!