Bob98SR5
11-10-2013, 01:12 PM
Edit: 5/16/14: I didn't adjust the pushrod length and it caused all sorts of crappiness under my foot. Read here to adjust it so that the clutch pedal height is correct:
http://www.ultimateyota.com/showthread.php?10628-Adjusting-clutch-pedal-after-slave-master-cylinder-replacement&p=111294#post111294
Well this one was a doozy.
As I posted before, my early morning starts on very cold mornings (even here in So Cal) have been challenging because the clutch (when depressed) would not allow gear shifting to occur. Things would get better once my 4runner warmed up. I decided to rebuild my master and slave cylinders, bought the rebuild kits, but discovered on a whim that Aisin mfgs new parts relatively cheap. I bought my replacement (new) clutch slave and master cylinders for less than $100. Due to time constraints, I was only going to change out the slave and do the master later. In retrospect, that would've been a horrible idea as bleeding is a time consuming b###h. But as fate would have it, both were needed.
So it was a very messy job, so no photos. But as many people recommend, change out both the slave and the master both at the same time. My master was jacked up and it would not push fluid at all once the slave was removed---but discovering this took a long time to realize because bleeding is a b###h. Lance and I struggled, changed out the slave back to the original one before Lance made a call to his mechanic buddy who suggested to change out the master too.
Long story short, here's some tips if you change them both out:
- Change them both out at the same time. Based on what I've read on the internets, both appear to fail at similar time frame. Plus, you really don't want to bleed twice!
Master cylinder
- remove the EVAP box. That gives you a lot of hand space to remove the MC. Take lots of photos just in case you forget where the hoses go. Believe it was 12mm bolts that hold the EVAP box down.
- Drain the MC reservoir using a turkey baster or the like.
- Use a flare nut wrench. Using a regular wrench tends to round out the nut on the line. 10mm
- Remove two nuts that secure the MC to the firewall. Can't recall if 10mm or 12. Lance, do you recall?
- On the other side, all there's to do is to remove the cotter pin from the roll nut (I think that's what it's called). Look at my clutch pedal bushing writeup and you'll see the cotter pin and roller pin (i think that's what its called; its brass in color w/ a flat rectangular end). Just pull out the cotter pin and then push the roll pin towards the left to pop it out. Now you can remove the MC
Slave Cylinder
- Through trial and error, best way is to remove the driver's side front tire and access the slave cylinder that way.
- There's a fitting that connects the line to the SC. Remove that. This is very time consuming.
- There is a bolt that secures the line to the transmission. It's to the lower right of the SC. Remove it to allow the line to wriggle free once you unthread the line from the SC. 12mm
- There's two nuts that secure the SC to the body of the tranny. 12mm. SC will just fall off
To reassemble:
- SC and MC: tighten down the nuts to the lines into the SC and MC body. DON'T secure the MC and SC first and then the line nuts. You'll go crazy, its not as easy.
- After performing the above, loosely secure the MC and SC bodies into the firewall and trans, respectively. For the MC, the fork on the driver's side end must straddle the clutch pedal itself. Once done, secure the roller pin and push the cotter pin through (was somewhat difficult, I'd use a locking pair of pliers next time to push cotter pin through)
- Once above is done, secure the bodies and then the flare nuts down. Don't over do the flare nuts. No, I don't know the torque specs.
Bleeding:
1) Since this was new to both of us, we had no idea if we were doing this right. It's a very time consuming process to bleed out the air because you are pumping the clutch pedal like nobody's business. So if there's a right way to do this, please let me know. But this is how we did it:
2) Person A pumps the pedal 20 times. One guy on the internet says flick the pedal with your foot, which causes the air bubbles to be jarred out of the lines and out the top of the uncapped MC reservoir. This seemed to work and Lance saw these little bubbles start to come out of the top reservoir. After the 20th flick of the pedal, person A holds down the clutch pedal to the floor and gives person B the all clear to open the flare nut.
3) Person B at the slave cylinder (with wrench at 9 o'clock) opens the flare nut to 6 o'clock and then pushes in the piston with his right hand to push out any air out of the SC body. Person B then secures the nut to 9 o'clock again and gives the all clear that the flare nut is closed.
4) Person A repeats step 2. Person B repeats step 3. Make sure to check the fluid level in the MC cylinder from time to time, especially in the beginning. Use DOT 3 brake fluid.
We repeated steps 2 and 3 about 4-5 times before feeling any firmness at the clutch pedal. The first few times, there was no pressure being built up at the pedal at all. I thought this wasn't working and bummed that something was not going right again. However after about the 4th or 5th time, I noticed one thing right away. When I held down the pedal and Lance cracked the line, I felt the pedal sinking even further down into the firewall. And once Lance closed the line, the pressure and firmness on the pedal increased. It takes a while, so be patient.
After the 4th - 5th time, Lance stopped pressing in the piston because the pressure was already built up and it was too difficult to press the piston in. That should be a good sign that you're doing the right thing. We must've repeated steps 2 and 3 (minus the pushing in the piston parts) about 15 times. Each time, the pushed in clutch pedal would sink less and less when the flare nut at the SC was cracked open. Oh, Lance said to quickly open and close the SC line. He did not too that in the beginning, airy foam would come out. Towards the end of the bleeding, just a tiny bubble or two would come out.
I drove Lance back to his place in LA and I could immediately tell that shifting was so much easier because I didn't have to press the clutch pedal down so far. I think I paid less than $100 for both the MC and SC (SC was about $25 as I recall).
I'm going to rebuild the MC and SC as originally intended, but I do recommend to just buy new parts as the cost isn't going to truly break the bank, these parts are very important to getting you going, and the time to bleed a second time will drive you nuts.
One more thing: I do have a brake bleeder which I forgot at home. Perhaps using one would've cut down the bleeding time.
http://www.ultimateyota.com/showthread.php?10628-Adjusting-clutch-pedal-after-slave-master-cylinder-replacement&p=111294#post111294
Well this one was a doozy.
As I posted before, my early morning starts on very cold mornings (even here in So Cal) have been challenging because the clutch (when depressed) would not allow gear shifting to occur. Things would get better once my 4runner warmed up. I decided to rebuild my master and slave cylinders, bought the rebuild kits, but discovered on a whim that Aisin mfgs new parts relatively cheap. I bought my replacement (new) clutch slave and master cylinders for less than $100. Due to time constraints, I was only going to change out the slave and do the master later. In retrospect, that would've been a horrible idea as bleeding is a time consuming b###h. But as fate would have it, both were needed.
So it was a very messy job, so no photos. But as many people recommend, change out both the slave and the master both at the same time. My master was jacked up and it would not push fluid at all once the slave was removed---but discovering this took a long time to realize because bleeding is a b###h. Lance and I struggled, changed out the slave back to the original one before Lance made a call to his mechanic buddy who suggested to change out the master too.
Long story short, here's some tips if you change them both out:
- Change them both out at the same time. Based on what I've read on the internets, both appear to fail at similar time frame. Plus, you really don't want to bleed twice!
Master cylinder
- remove the EVAP box. That gives you a lot of hand space to remove the MC. Take lots of photos just in case you forget where the hoses go. Believe it was 12mm bolts that hold the EVAP box down.
- Drain the MC reservoir using a turkey baster or the like.
- Use a flare nut wrench. Using a regular wrench tends to round out the nut on the line. 10mm
- Remove two nuts that secure the MC to the firewall. Can't recall if 10mm or 12. Lance, do you recall?
- On the other side, all there's to do is to remove the cotter pin from the roll nut (I think that's what it's called). Look at my clutch pedal bushing writeup and you'll see the cotter pin and roller pin (i think that's what its called; its brass in color w/ a flat rectangular end). Just pull out the cotter pin and then push the roll pin towards the left to pop it out. Now you can remove the MC
Slave Cylinder
- Through trial and error, best way is to remove the driver's side front tire and access the slave cylinder that way.
- There's a fitting that connects the line to the SC. Remove that. This is very time consuming.
- There is a bolt that secures the line to the transmission. It's to the lower right of the SC. Remove it to allow the line to wriggle free once you unthread the line from the SC. 12mm
- There's two nuts that secure the SC to the body of the tranny. 12mm. SC will just fall off
To reassemble:
- SC and MC: tighten down the nuts to the lines into the SC and MC body. DON'T secure the MC and SC first and then the line nuts. You'll go crazy, its not as easy.
- After performing the above, loosely secure the MC and SC bodies into the firewall and trans, respectively. For the MC, the fork on the driver's side end must straddle the clutch pedal itself. Once done, secure the roller pin and push the cotter pin through (was somewhat difficult, I'd use a locking pair of pliers next time to push cotter pin through)
- Once above is done, secure the bodies and then the flare nuts down. Don't over do the flare nuts. No, I don't know the torque specs.
Bleeding:
1) Since this was new to both of us, we had no idea if we were doing this right. It's a very time consuming process to bleed out the air because you are pumping the clutch pedal like nobody's business. So if there's a right way to do this, please let me know. But this is how we did it:
2) Person A pumps the pedal 20 times. One guy on the internet says flick the pedal with your foot, which causes the air bubbles to be jarred out of the lines and out the top of the uncapped MC reservoir. This seemed to work and Lance saw these little bubbles start to come out of the top reservoir. After the 20th flick of the pedal, person A holds down the clutch pedal to the floor and gives person B the all clear to open the flare nut.
3) Person B at the slave cylinder (with wrench at 9 o'clock) opens the flare nut to 6 o'clock and then pushes in the piston with his right hand to push out any air out of the SC body. Person B then secures the nut to 9 o'clock again and gives the all clear that the flare nut is closed.
4) Person A repeats step 2. Person B repeats step 3. Make sure to check the fluid level in the MC cylinder from time to time, especially in the beginning. Use DOT 3 brake fluid.
We repeated steps 2 and 3 about 4-5 times before feeling any firmness at the clutch pedal. The first few times, there was no pressure being built up at the pedal at all. I thought this wasn't working and bummed that something was not going right again. However after about the 4th or 5th time, I noticed one thing right away. When I held down the pedal and Lance cracked the line, I felt the pedal sinking even further down into the firewall. And once Lance closed the line, the pressure and firmness on the pedal increased. It takes a while, so be patient.
After the 4th - 5th time, Lance stopped pressing in the piston because the pressure was already built up and it was too difficult to press the piston in. That should be a good sign that you're doing the right thing. We must've repeated steps 2 and 3 (minus the pushing in the piston parts) about 15 times. Each time, the pushed in clutch pedal would sink less and less when the flare nut at the SC was cracked open. Oh, Lance said to quickly open and close the SC line. He did not too that in the beginning, airy foam would come out. Towards the end of the bleeding, just a tiny bubble or two would come out.
I drove Lance back to his place in LA and I could immediately tell that shifting was so much easier because I didn't have to press the clutch pedal down so far. I think I paid less than $100 for both the MC and SC (SC was about $25 as I recall).
I'm going to rebuild the MC and SC as originally intended, but I do recommend to just buy new parts as the cost isn't going to truly break the bank, these parts are very important to getting you going, and the time to bleed a second time will drive you nuts.
One more thing: I do have a brake bleeder which I forgot at home. Perhaps using one would've cut down the bleeding time.