How to Replace Clutch Slave Cylinder on a Jeep Wrangler JK

Chris

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The slave cylinder moves the throw out bearing against the clutch pressure plate. This removes pressure from the clutch disc, keeping engine torque from traveling through the transmission. If the clutch disc was unable to depressurize, smooth shifting would not be possible. Brake fluid from the master cylinder reservoir travels through the hydraulic lines connected to the clutch master cylinder and slave cylinder. Brake fluid is not compressible, which allows the clutch pedals movement to act as a force against the rod in the slave cylinder.

Nov-19-Slave-Cylinder-118342.png


Materials Needed
  • Floor jack
  • Jack stands (x2)
  • 3/8" ratchet
  • 10mm-14mm sockets
  • Flat head screwdriver or pick
  • Rubber gloves
  • Safety glasses
  • Slave cylinder
  • DOT 3 brake fluid
Step 1 – Raise and support the front end
Engage your parking brake. Place your floor jack below one of the front jacking points and raise it until you can fit a jack stand beside it. Lower your Jeep's weight onto the jack stand and repeat the process for the other side.

DSC00072-118337.jpg

Figure 1. Jack up on the frame and put stands under the axle.

Step 2 – Remove mounting nuts from slave cylinder
The slave cylinder is located on the driver's side of the transmission, near the front. Two mounting nuts hold it to the transmission.

wranglersalvecylinderdiagramcorrected-116673.jpg

Figure 2. A diagram of the slave cylinder.

Step 3 – Remove hydraulic line from slave cylinder
Use a pick or flat head screwdriver to move the metal clip to the unlocked position. Place your pick or screwdriver between the exposed portion of the clip and hydraulic line. Pull the metal clip away from the line until it clicks into the unlock position. Slide the hydraulic line out of the metal bracket. Remove the line from the slave cylinder with a pull/twist. There is a rubber O-ring at the bottom of this line. Make sure this O-ring is not damaged prior to install, otherwise the line will leak.

wranglerlineclipcorrect-116675.jpg

Figure 3. The hydraulic line bracket and clip.

Step 4 – Install new slave cylinder
Slide the slave cylinder onto the transmission studs, and then slide the hydraulic line bracket onto the top stud. Push the hydraulic line into the slave cylinder, making sure the rubber O-ring is installed. Begin tightening the mounting nuts, and then position the hydraulic line bracket upwards to connect the the line. Slide the line into the bracket and torque the mounting nuts to 17 ft/lbs.

Step 5 – Bleed slave cylinder
You will need a second person to bleed the slave cylinder. Fill the brake master cylinder fluid reservoir to the "max" level. You will see where it says min/max on the side. Use DOT 3 brake fluid. Remove the rubber dust cap from the bleed screw (see Figure 2). Turn the bleed screw half a turn while another person has the clutch pedal depressed. Make sure you're wearing rubber gloves and safety glasses. Brake fluid will come out of the screw at a high velocity. Once the pressure is gone (a couple seconds), close the screw and have the other person pump the clutch pedal about ten times. Repeat the bleeding process several times to achieve a responsive clutch pedal.
 
Chris,

I replaced my slave cylinder when I replaced my clutch, but it has leaked a little ever since, requiring additional fluid periodically. Now that the weather has turned cold, it is leaking more, and needs to be primed before it can be driven if it sits more than 24hrs. Can you point me to a parts break down. The o-ring looked worn when I replaced the slave cylinder, and I suspect that is the source of the leak. I just need to know that size to get, and can't find this information.

Thanks
 
Chris,

I replaced my slave cylinder when I replaced my clutch, but it has leaked a little ever since, requiring additional fluid periodically. Now that the weather has turned cold, it is leaking more, and needs to be primed before it can be driven if it sits more than 24hrs. Can you point me to a parts break down. The o-ring looked worn when I replaced the slave cylinder, and I suspect that is the source of the leak. I just need to know that size to get, and can't find this information.

Thanks


I just got done replacing mine also and the slave was leaking at the line, I found out that then line wasn't perfectly straight going into the slave. I loosened the nut where the bracket is that holds the line in a straight line so it looked straighter. Hasn't leaked since then, also I found out that you can't just buy the beveled seals. I lost the one from the slave and had to buy a new line just to get a seal.
 
Thanks Blackjku. I'll try that. If realigning it doesn't work, where did you get the replacement line?


https://www.amazon.com/dp/B00I6MTALY/?tag=jkforum-20, but any major parts store should have one.

Just a word to save you alot of time and cuss words, don't replace the line unless you absolutely have to. It's easier to take the inner fender cover out and go in from the side.

Also i'm finding the easiest way to bleed it is to jack the front up and pump the pedal until you feel it getting harder to push. Then let it sit for a while and come back and see if it's still firm like it was, if it isn't do it again. It's taken quite a few times but mine's getting there, I tried bleeding it at the bleeder but wasn't making much progress.