How to Replace the Slave Cylinder on Vehiclesby Contributing WriterUpdated June 12, 2017
The clutch slave cylinder on the Vehicles attaches to the side of the manual transmission. The clutch pedal has to be depressed to generate pressure though the fluid line to activate the clutch slave cylinder, which disengages the clutch assembly --- taking the Vehicles out of gear. A faulty slave cylinder that has too much air or cracked seals can cause hard or no shifting response. It can also cause the clutch pedal to fall to the floor. Replacing the clutch slave cylinder can be performed by the do-it-yourself repair person, following some simple steps and using basic tools.
Under The Hood:
- How to Replace the Slave Cylinder on a Jeep Wrangler
- How to Replace a Slave Cylinder in a Ranger
- How to Replace a Slave Cylinder on a 1997 Eclipse
- How to Replace a Slave Cylinder in a Toyota Truck
- How to Replace the Slave Cylinder on a Cavalier
Raise the Jeep's front end with your floor jack -- an aftermarket jack works much better than the stock one -- and support it on jack stands place under the frame rails.
Open the cap on the clutch master cylinder and siphon the fluid out of the cylinder using a turkey baster or similar siphon tool.
Disconnect the hose connecting the slave cylinder to the master cylinder using a hose clamp tool if the line can be disconnected.
Remove the mounting nuts that fasten the slave cylinder to the clutch housing with your wrench. Remove any fasteners connecting it to the master cylinder and remove the slave cylinder, making sure you don't spill fluid. Proceed to Section 2.
Disengage the hydraulic line from the clips connecting it to the body if you cannot separate the slave cylinder from the rest of the assembly, then remove the lower nut connecting the master cylinder to the firewall on the engine side.
Remove the master cylinder's mounting nut from under the dash in the Jeep and unclip/disconnect the pushrod from the clutch pedal.
Lift and remove the master/slave cylinder assembly from the engine compartment.
Install the master cylinder assembly against the firewall in the engine compartment and connect its lower mounting nut without tightening it all the way. Skip to Step 3 if you are only installing the slave cylinder.
Connect and tighten the mounting nut within the Jeep's driver compartment and reconnect the pushrod, then tighten the engine side nut the rest of the way. Proceed to Step 4.
Connect the replacement slave cylinder to the master cylinder and the hydraulic line.
Connect the slave cylinder to the clutch assembly, attaching its own pushrod into the clutch opening and tightening its mounting bolts. Connect the hydraulic line to the Jeep body with its clips.
Lower the vehicle off the jack stands.
Fill the slave cylinder -- and master cylinder if needed -- with fresh brake fluid.
Open the bleeder screw on the slave cylinder and have another person push on the clutch pedal to bleed air out of the cylinder; hold a small container to the bleeder valve to catch the fluid. Repeat this for the master cylinder.
Items you will need
Hose clamp tool
DOT 3 brake fluid
Park your Ranger on a level spot and disconnect the negative cable from your battery. Engage the parking brake and place a chock block under one of the tires (which one does not matter). Shift the transmission into neutral.
Locate the master clutch cylinder. The master cylinder will be on the driver's side firewall (the wall of the truck between the engine compartment and the passenger cab). The cap of the reservoir is marked "Clutch Fluid" so it is easy to find. Follow the hydraulic hose that is attached to the bottom of the master cylinder down to where it terminates. Where it terminates is the slave cylinder.
Remove the hydraulic hose from the slave cylinder using an open box wrench. Plug the end of the hose with a hose plug to prevent fluid from leaking out or any debris from entering the line.
Loosen the nut on the end of the slave cylinder that is pointed toward the rear of the truck. Remove the nut and washer on that end.
Slide the old slave cylinder off the shaft.
Push the new slave cylinder onto the shaft and make sure that the hydraulic fitting is turned in the same way that the one on the old slave was. Then replace the washer and nut and tighten them.
Bleed the lines before connecting your new slave. Pour an inch of new clutch fluid into a glass jar. Unplug the hydraulic hose and put that end in the fluid in the jar. Open up the reservoir on the master cylinder and add fluid until it reaches the "Max" line. Pump the clutch pedal. When the end of the hose in the glass jar of fluid is no longer blowing air bubbles, attach the line to the slave cylinder. Attach a rubber hose to the bleed valve on your slave cylinder. Place the end of the tube in the jar of fluid and repeat the process of bleeding until no bubbles appear. Close the bleed valve before you remove the hose.
Items you will need
Open box wrench set
Disconnect the negative battery cable under the hood. The cable should be black.
Locate the slave cylinder on the side of the transmission under the car. It should look like an L-shaped cylinder with a little rod pushing into one end, and a hose coming out of the other.
Squeeze the hose clamp that connects the fluid line to the slave cylinder and disconnect it, letting the fluid drain into a plastic or glass container.
Use a wrench to unscrew the two bolts that fasten the cylinder to the transmission, and pull the cylinder off. The push rod should come loose when the cylinder is removed.
Fasten the new cylinder in the same position using the same bolts.
Place some all-purpose-grease where the push rod pushes the plunger on the cylinder and put the end of the push rod back in place. It should go in the same location as the rod was in the old cylinder and fit into a little pocket on the end of the plunger.
Attach the hose using the same clamp taking care to get the hose pushed as far down on the port as possible.
Bleeding the system
Fill the system with Dot 3 brake/clutch fluid. The fluid reservoir is located under the hood and should look like a white cup with a rubber lid. Be sure that it says "clutch" on it and not "brake," because the two reservoirs look similar.
Have someone sit in the car and depress the clutch a couple of times holding it down on the last time.
Loosen the bleeder valve on the slave cylinder slowly while the clutch is depressed. Some air bubbles should come out at first. Close it as soon as a stream starts to come out.
Fill the valve reservoir again and repeat the steps until there are no air bubbles coming out when the bleeder valve is opened.
Items you will need
Plastic bottle larger than 12 ounces
DOT 3 hydraulic fluid
All purpose auto grease
Set the shifter in gear on your truck and pull the emergency brake. For safety, use a socket and wrench to loosen and remove the negative battery cable. Place a floor jack under the rear of the truck and lift it to place two jack stands under the frame. Lift the front of the truck with the floor jack and set two jack stands under the frame. Slide a large drain pan under the manual transmission. Use a shop light to locate the slave cylinder. It looks like a small valve, bolted to the transmission. Look for the clutch fluid line connected to it.
Spray liberal amounts of penetrating oil on the line fitting and let it soak for five minutes. Place a fuel line wrench on the flared line nut and turn it counterclockwise. Shock the wrench with the palm of your hand, if it appears stubborn. Loosing the line fitting and let the clutch fluid drain into the pan. Use a socket and wrench to loose and remove the two retaining bolts on the slave cylinder. Pull it off the transmission and discard it.
Clean the mounting surface on the transmission case with carburetor cleaner and a rag. Place the new slave cylinder up against the transmission case and start the mounting bolts in by hand. Tighten both bolts firmly with the socket and wrench, but do not over-tighten them --- the aluminum transmission case could crack. Screw the line fitting on by hand, making sure not to cross-thread it.
Tighten the line fitting with the fuel line wrench. Go to your engine compartment and locate the clutch master cylinder --- refer to your repair manual. Take the rubber cap off of it and fill it to the top with certified clutch fluid. Leave the cap off. Go under the vehicle and place a fuel line wrench on the small bleeder screw on the slave cylinder. Ask an assistant to depress the clutch to the floor and hold it there. Open the bleeder valve and let the clutch fluid escape. If the fluid pops and hisses, it indicates air in the system.
Close the bleeder valve and instruct your assistant to slowly pump the clutch pedal up and down several times then hold it to the floor. Open the bleeder valve again, letting the clutch fluid escape. Continue this process until no air appears, but only a steady stream of fluid. Always keep the clutch master cylinder filled to the top while performing the bleeding process. When clean fluid exits the bleeder screw, with no air, tighten the bleeder screw. Remove the drain pan.
Refill the clutch master cylinder and replace the cap. Replace the negative battery cable and tighten it with a socket and wrench. Lift the vehicle with the floor jack to remove the jack stands. Start the engine and shift through the gears. Check for proper gear engagement and proper free-play in the clutch pedal.
Items you will need
Fuel line wrench
Clutch slave cylinder
Owner's repair manual
Raise the hood and locate the master cylinder on the driver's side of the firewall. Find the electrical connector that is attached to it and remove it.
Slide a drain pan underneath the master cylinder. This will catch any falling brake fluid. Remove the brake lines from the cylinder with a wrench. Be sure to install plugs into these lines to avoid contamination.
Remove the cylinder assembly by removing the nuts that hold it to the firewall. Loosen these nuts with a wrench. On some vehicles, the cylinder may be attached to a brake booster in the same manner.
Install the new master cylinder to the brake booster or firewall. Secure it with the nuts and tighten them to 22 to 30 foot-pounds.
Remove the plugs on the ends of the brake lines. Attach the lines to the master cylinder, but do not over-tighten them. Tighten them to 10-15 foot-pounds with a torque wrench.
Locate the electrical cable and reattach it to the master cylinder.
Fill the brake reservoir with brake fluid and prepare to bleed the brakes.
Bleed the break system of air. This is done with help of an assistant. Have your assistant depress the brake pedal and hold it. Open the bleed ports located on or near the brake calipers with a wrench. Allow fluid to come out of the port. Close the bleed port and stop pressing the brake pedal. Repeat this process until there are no more air bubbles coming from the bleed port. Continue to monitor the fluid level in the master cylinder as this process moves along.
Test-drive the vehicle to make sure the brakes operate properly.
Items you will need
Fluid drain pan
Open-ended wrench set
Dot 3 brake fluid