DIY replacing clutch master cylinder
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DIY replacing clutch master cylinder
In my campaign to sort out some intermittent clutch feel issues, I recently replaced my clutch master cylinder. I couldn't find a good HOWTO w/ search, so thought I'd post one up. This mostly matches the service manual, with some added commentary on my part for technique.
Tools required:
8mm open end wrench (or better yet a flare nut wrench aka hydraulic line wrench)
12mm (deep) socket w/ extension
Turkey baster
1/4" inner diameter clear plastic tubing
New container of brake fluid
Empty container for old fluid disposal
Shop towels
Latex gloves (optional but recommended to keep brake fluid off your hands)
1. Jack the car up, preferably front and rear. You'll need to be able to get underneath to bleed the clutch fluid later.
2. Pop the hood. Use shop towels or newspaper to cover the area around and underneath the clutch master reservoir. Brake fluid is bad stuff, and you will spill.
3. Open the clutch reservoir and use the turkey baster to suck out as much of the fluid as possible (note: clutch fluid is DOT3 brake fluid) and dump it into your disposal container.
4. Use your 8mm open end wrench to remove the clutch line from the side of the master cylinder. It's closest to the fender. The spec on this fitting is 11 ftf-lb torque, which is very little, but I found mine was significantly tighter. I held the master cylinder while loosening the fitting to keep the metal line from bending around too much. The line may drip some fluid when you remove it, so be prepared to soak it up with a shop towel.
(Edit: Careful using a regular open end wrench on a hydraulic line nut. The nuts can strip very easily. A better tool is a flare nut wrench. They can be found at Sears and some parts stores like NAPA.)
5. Now squeeze your cranium into the drivers side footwell. You'll see the clutch pedal is attached to the master cylinder by a large pin ("yoke pin"), which is held in place by a smaller cotter pin ("lock pin"). Remove the lock and yoke pins.
6. The master cylinder itself is attached to the firewall by two 12mm nuts inside the driver's footwell -- one on the lower right (relative to the master cylinder), and the other on the upper left behind a metal bracket. Removing the lower right one should be straightforward.
The upper left nut took me much longer to figure out, because the metal bracket and ECU are in the way. Basically you need to attach an extension to your ratchet. If you don't have a 12mm deep socket, you can use a regular socket by putting it halfway on the end of your extension, so the threaded bolt to which the nut is attached doesn't prevent the socket from engaging the nut.
7. Remove the master cylinder by pulling directly outward from the hood side of the firewall. You may have to tug on the clutch line to move it out of the way -- don't worry, the metal is springy and won't break.
8. Install the new master cylinder, put everything back together the same way you took it apart, bleed the clutch and you're done!
Tools required:
8mm open end wrench (or better yet a flare nut wrench aka hydraulic line wrench)
12mm (deep) socket w/ extension
Turkey baster
1/4" inner diameter clear plastic tubing
New container of brake fluid
Empty container for old fluid disposal
Shop towels
Latex gloves (optional but recommended to keep brake fluid off your hands)
1. Jack the car up, preferably front and rear. You'll need to be able to get underneath to bleed the clutch fluid later.
2. Pop the hood. Use shop towels or newspaper to cover the area around and underneath the clutch master reservoir. Brake fluid is bad stuff, and you will spill.
3. Open the clutch reservoir and use the turkey baster to suck out as much of the fluid as possible (note: clutch fluid is DOT3 brake fluid) and dump it into your disposal container.
4. Use your 8mm open end wrench to remove the clutch line from the side of the master cylinder. It's closest to the fender. The spec on this fitting is 11 ftf-lb torque, which is very little, but I found mine was significantly tighter. I held the master cylinder while loosening the fitting to keep the metal line from bending around too much. The line may drip some fluid when you remove it, so be prepared to soak it up with a shop towel.
(Edit: Careful using a regular open end wrench on a hydraulic line nut. The nuts can strip very easily. A better tool is a flare nut wrench. They can be found at Sears and some parts stores like NAPA.)
5. Now squeeze your cranium into the drivers side footwell. You'll see the clutch pedal is attached to the master cylinder by a large pin ("yoke pin"), which is held in place by a smaller cotter pin ("lock pin"). Remove the lock and yoke pins.
6. The master cylinder itself is attached to the firewall by two 12mm nuts inside the driver's footwell -- one on the lower right (relative to the master cylinder), and the other on the upper left behind a metal bracket. Removing the lower right one should be straightforward.
The upper left nut took me much longer to figure out, because the metal bracket and ECU are in the way. Basically you need to attach an extension to your ratchet. If you don't have a 12mm deep socket, you can use a regular socket by putting it halfway on the end of your extension, so the threaded bolt to which the nut is attached doesn't prevent the socket from engaging the nut.
7. Remove the master cylinder by pulling directly outward from the hood side of the firewall. You may have to tug on the clutch line to move it out of the way -- don't worry, the metal is springy and won't break.
8. Install the new master cylinder, put everything back together the same way you took it apart, bleed the clutch and you're done!
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Thanks, negcamber. These forums have been extremely useful to me, so I'm glad to contribute!
ninja edit: I'll try to remember to take pics next time. While I was working on the car I actually spent most of my time figuring out (read: cursing) how to get to the one 12mm nut, so documentation pics weren't really on my mind
ninja edit: I'll try to remember to take pics next time. While I was working on the car I actually spent most of my time figuring out (read: cursing) how to get to the one 12mm nut, so documentation pics weren't really on my mind
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#8
If you want to save some time bleeding the clutch system you can "bench bleed" the master before you go in for the install. Otherwise great write up. I have pictures i took during my install to do a write up but i saw there was one already.
To bench bleed:
Prior to install fill the new master cylinder with new DOT3 brake fluid. Remove the end cap where the line would attach. Manually push in the clutch master with your hand till you see fluid coming out in a steady stream. Cap the end with the plastic plunger and cap the top of the master and your ready for install
This should save you a good bit of time bleeding the system.
Hope this helps someone.
-APoner
To bench bleed:
Prior to install fill the new master cylinder with new DOT3 brake fluid. Remove the end cap where the line would attach. Manually push in the clutch master with your hand till you see fluid coming out in a steady stream. Cap the end with the plastic plunger and cap the top of the master and your ready for install
This should save you a good bit of time bleeding the system.
Hope this helps someone.
-APoner
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