Can't get the Clutch Master Cylinder Bled !!!
07-18-2013, 11:22 AM
#1
Can't get the Clutch Master Cylinder Bled !!!
Sorry for the lengthy post, but I am trying to describe this as best I can because I REALLY need some help to get going !!!!
I have done a ton of searching, and found many good ideas, but I am still stuck !!!!
I was having problems getting my 4Runner manual transmission into 1st gear and reverse. If I stepped the clutch pedal waaay to the floor it still did not want to go into gear. The condition deteriorated (even though I was not driving it but a few miles here and there) and it went from hard-to-get-into-gear to the point where I had to shut the vehicle off, put it in first then start it to get it in the driveway for repair.
I started out with the Marlin shifter bushing. The original bushing looked okay, I replaced it with the Marlin parts and it didn’t seem to change a thing. I also replaced the trans oil with synthetic Lucas gear oil of the correct weight. Still no change.
The clutch did not seem to be slipping so I thought maybe the clutch master cylinder was weak, I ordered an Aisin Clutch Master Cylinder and Aisin Clutch Slave cylinder. I removed the master cylinder, then removed the slave cylinder. The fluid looked like green mud, so I blew the line out lightly with compressed air. I replaced both units and hooked up the lines.
I tried to bleed it by having someone push down on the clutch, then I would crack the bleeder on the slave cylinder. The slave cylinder would compress and force some fluid out, I would quickly close the bleeder so no air would get in. We tried this many times and still had a soft clutch feel and could not shift at all, much worse than when the original master was in use.
After no success here, I read about bench bleeding but did not think I could get the lines out of the engine compartment. I unbolted the slave cylinder and pushed the rod the whole way in, slowly and several times, thinking I could get the air out, and put it back together. Still no clutch.
After that, I borrowed a MityVac and tried to bleed it using vacuum at the bleeder on the slave. When stepping on the clutch after that, the slave would move the fork an inch, but not nearly enough to do it’s job.
In desperation, I saw on Youtube where a guy bought a new weedsprayer and rigged it up to pump brake fluid in thru the bleeder. I watched for air bubbles and carefully did that, I had to empty the reservoir a few times to allow for more fluid coming in from the bottom, but I still got a spongy pedal that only moves the slave an inch.
I really need to get this resolved, any tips would be appreciated! Is there a possibility that the new master is no good?
I have done a ton of searching, and found many good ideas, but I am still stuck !!!!
I was having problems getting my 4Runner manual transmission into 1st gear and reverse. If I stepped the clutch pedal waaay to the floor it still did not want to go into gear. The condition deteriorated (even though I was not driving it but a few miles here and there) and it went from hard-to-get-into-gear to the point where I had to shut the vehicle off, put it in first then start it to get it in the driveway for repair.
I started out with the Marlin shifter bushing. The original bushing looked okay, I replaced it with the Marlin parts and it didn’t seem to change a thing. I also replaced the trans oil with synthetic Lucas gear oil of the correct weight. Still no change.
The clutch did not seem to be slipping so I thought maybe the clutch master cylinder was weak, I ordered an Aisin Clutch Master Cylinder and Aisin Clutch Slave cylinder. I removed the master cylinder, then removed the slave cylinder. The fluid looked like green mud, so I blew the line out lightly with compressed air. I replaced both units and hooked up the lines.
I tried to bleed it by having someone push down on the clutch, then I would crack the bleeder on the slave cylinder. The slave cylinder would compress and force some fluid out, I would quickly close the bleeder so no air would get in. We tried this many times and still had a soft clutch feel and could not shift at all, much worse than when the original master was in use.
After no success here, I read about bench bleeding but did not think I could get the lines out of the engine compartment. I unbolted the slave cylinder and pushed the rod the whole way in, slowly and several times, thinking I could get the air out, and put it back together. Still no clutch.
After that, I borrowed a MityVac and tried to bleed it using vacuum at the bleeder on the slave. When stepping on the clutch after that, the slave would move the fork an inch, but not nearly enough to do it’s job.
In desperation, I saw on Youtube where a guy bought a new weedsprayer and rigged it up to pump brake fluid in thru the bleeder. I watched for air bubbles and carefully did that, I had to empty the reservoir a few times to allow for more fluid coming in from the bottom, but I still got a spongy pedal that only moves the slave an inch.
I really need to get this resolved, any tips would be appreciated! Is there a possibility that the new master is no good?
07-18-2013, 11:57 AM
#2
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I read your post and I did not read anything about you did a gravity bleed. I would try doing that first. Instali a tube on the slade cylinder bleeder and place it in a jar try to use a clear tube. That way you can see the air bubbles come threw. Just keep adding the fluid through the master don't let it run dry. And do not pump on the clutch pedal while you're doing a gravity bleed.
07-18-2013, 12:29 PM
#3
Bleeding the clutch is not your problem my friend. From what I've read you have clearly bleed it more then once.
All you need to do is adjust the clutch pedal. If you look under your dash you will see that there's a rid connected to the pedal that has a nut on it. Loosen the nut. 12mm wrench. Now turn that rod with your fingers. Watch as you turn it because its going to shove out on the clutch pedal. Make sure you do not over adjust it. If you do then your going to burn up your clutch. Once you have it adjusted tighten down the nut.
That's it ole buddy. Let me know how it goes
All you need to do is adjust the clutch pedal. If you look under your dash you will see that there's a rid connected to the pedal that has a nut on it. Loosen the nut. 12mm wrench. Now turn that rod with your fingers. Watch as you turn it because its going to shove out on the clutch pedal. Make sure you do not over adjust it. If you do then your going to burn up your clutch. Once you have it adjusted tighten down the nut.
That's it ole buddy. Let me know how it goes
07-18-2013, 12:46 PM
#5
No no.... Leave it hooked up. Do not pull the pin. Just loosen the nut. Turn the rod until it gets hard to turn with your fingers. Tighten nut and your good to go. Now your only gonna want a 1/8" to 1/4" of free travel in your pedal. If you have no free travel then your clutch is going to be compressed alittle Making it slip. Not really noticeable slip but you will smell it.
07-18-2013, 12:56 PM
#6
If that does not fix your problem adjusting the rod.
It is possible you have a bad connection allowing a very slight fluid leak but enough to draw air into the system
Compare the two slave cylinders and master cylinders it is possible you got the wrong parts .
Perhaps you ordered them wrong ??
Could be boxed wrong??
Lets us also not forget the broken clutch pedal bracket??
It is possible you have a bad connection allowing a very slight fluid leak but enough to draw air into the system
Compare the two slave cylinders and master cylinders it is possible you got the wrong parts .
Perhaps you ordered them wrong ??
Could be boxed wrong??
Lets us also not forget the broken clutch pedal bracket??
07-18-2013, 01:41 PM
#7
I will do some checking on the parts to be sure they are right, I sure thought they were....
I looked over the clutch pedal bracket pretty well, it appears to be okay. I had my buddy push down the clutch hard while I looked at the master and the firewall and did not notice flex that could come from a crack.
I looked over the clutch pedal bracket pretty well, it appears to be okay. I had my buddy push down the clutch hard while I looked at the master and the firewall and did not notice flex that could come from a crack.
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07-18-2013, 02:01 PM
#8
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I just had a problem bleeding my clutch slave yesterday on my 3.4 swap. Never had this problem before. Bled it a bunch of times, Mity-Vac, etc.
What finally worked was pulling the slave piston out all the way, not literally out of the bore. Max out travel. Rubber boot and push rod were out.
Took the top off the reservoir and left it off after filling it.
Put the slave back on without the push rod to the fork or boot in place. Don't push the clutch pedal!
Hooked the line up and opened the bleeder and let gravity fill the maxed out slave.
Then slightly opened the bleeder again while pushing the slave piston in and installing the push rod.
This allowed a FULL slave without pumping the pedal and when I pushed the slave piston back in, it bled out the air.
Stuck the rubber boot and rod back in place to the fork. Tried it out and worked great.
Check for air one more time if you feel the need.
What finally worked was pulling the slave piston out all the way, not literally out of the bore. Max out travel. Rubber boot and push rod were out.
Took the top off the reservoir and left it off after filling it.
Put the slave back on without the push rod to the fork or boot in place. Don't push the clutch pedal!
Hooked the line up and opened the bleeder and let gravity fill the maxed out slave.
Then slightly opened the bleeder again while pushing the slave piston in and installing the push rod.
This allowed a FULL slave without pumping the pedal and when I pushed the slave piston back in, it bled out the air.
Stuck the rubber boot and rod back in place to the fork. Tried it out and worked great.
Check for air one more time if you feel the need.
07-18-2013, 03:30 PM
#9
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If only the bleeder was Engineered better it would be easier to bleed. But your step is my next step. I just did one last week after the owner remove both master and slave Cylinder.
07-18-2013, 06:19 PM
#10
Well, I tried a bunch of stuff. no luck.
I compared parts, they look for all the world to be right.
I did a gravity bleed, ran a lot of dot3 thru, then adjusted the master rod out. The rod was so far out that I thought I would run out of threads. pumped the clutch, enough to move the slave a little, not enough to disengage the clutch.
The Yota was parked facing uphill in my relatively steep driveway. So I turned it around, not fun with no clutch. I tried the procedures again when facing downhill, thought maybe an air bubble would move being on a different angle but nothing.
Did the procedure of removing the slave and extending out then moving the slave in and out and bled again.
No joy.
Could the new master be bad?
Could something have happened in the fork or clutch to make it act this way?
I compared parts, they look for all the world to be right.
I did a gravity bleed, ran a lot of dot3 thru, then adjusted the master rod out. The rod was so far out that I thought I would run out of threads. pumped the clutch, enough to move the slave a little, not enough to disengage the clutch.
The Yota was parked facing uphill in my relatively steep driveway. So I turned it around, not fun with no clutch. I tried the procedures again when facing downhill, thought maybe an air bubble would move being on a different angle but nothing.
Did the procedure of removing the slave and extending out then moving the slave in and out and bled again.
No joy.
Could the new master be bad?
Could something have happened in the fork or clutch to make it act this way?
07-19-2013, 04:25 AM
#12
BEORE, the pedal before was like a bear trap, I used to drive a 5 speed S10, so when I first got the 4Runner I was shocked how much force it took to clutch, you really have to stand on it. NOW, it easily pushes down and comes back up, I can reach it with my hand and pump it up and down.
EXCELLENT question wyoming9, does anyone know what the slave cylinder travel should be to fully operate the clutch?
EXCELLENT question wyoming9, does anyone know what the slave cylinder travel should be to fully operate the clutch?
07-19-2013, 01:11 PM
#14
Registered User
It also has ZERO info on HOW to bleed the clutch, although it does say "bleed the clutch" in several places.
I used my homemade pressure bleeder when I changed fluid (for the first time ever) last year. I can't remember exactly how I did it--I was just making it up as I went along. But I got the old stuff out, the new stuff in, and it works just like it always has.
Last edited by TheDurk; 07-19-2013 at 01:19 PM.
07-19-2013, 06:40 PM
#15
I am thinking either a bad connection or mechanical problems in the clutch itself.*** At any time before you changed your hydraulics did you have the clutch pedal just sink to the floor??
When you removed either the master or slave have fluid inside the rubber boot???
Did you need to be adding fluid between using the vehicle??
I am worried about the green mud!!!*** just what caused this I wonder if you did not get some of this into the new slave cylinder??
At any time before attaching the line to the new slave cylinder did you allow gravity to flow new clean fluid through the line.
If you have a hydraulic problem this could be the cause.
At no time did I see any mention of changing the rubber hose in the system these hoses at times can get to the point they can balloon ( hose expands instead of moving the cylinder) causing lack of movement in the cylinder.
Can also be a over looked problem in brakes as well
Is this making any noises ??
How does it go into the other gears??
You are using #3 DOT brake fluid??
Just how many miles on the clutch compared to the truck over all ??
07-20-2013, 04:35 AM
#16
I am thinking either a bad connection or mechanical problems in the clutch itself.*** At any time before you changed your hydraulics did you have the clutch pedal just sink to the floor??
No, the clutch was hard to push in, but never sunk to floor.
When you removed either the master or slave have fluid inside the rubber boot???
No, nice and dry.
Did you need to be adding fluid between using the vehicle??
No, never had to add fluid.
I am worried about the green mud!!!*** just what caused this I wonder if you did not get some of this into the new slave cylinder??
I took off the slave and master and lightly blew compressed
air thru the line, but it's possible it was not completely out.
At any time before attaching the line to the new slave cylinder did you allow gravity to flow new clean fluid through the line.
No, just air.
If you have a hydraulic problem this could be the cause.
At no time did I see any mention of changing the rubber hose in the system these hoses at times can get to the point they can balloon ( hose expands instead of moving the cylinder) causing lack of movement in the cylinder.
Can also be a over looked problem in brakes as well
I will look at the hose today.
Is this making any noises ??
The clutch fork squeaks pretty good when it travels a little.
How does it go into the other gears??
Before, 1st and reverse were hard to get into.
Now, with no clutch disengagement, it goes into no
gears. With the engine off, it shifts smoothly.
You are using #3 DOT brake fluid??
Yes, new, clean Dot #3.
Just how many miles on the clutch compared to the truck over all ??
I bought it with 135K, it now has 160K, it could be original.
The plan was to do the clutch too, but I thought I would start here.
07-20-2013, 08:50 AM
#17
I always change the rubber hose when I do the cylinders as it is a wearing part of the hydraulics
If it were me I would pull the slave cylinder off Take it apart and have a look clean if needed
Run some clean brake fluid through the line with gravity .
It should flow free with the hot weather even more so
When you were bleeding when you opened the bleeder under pressure the fluid should shoot out.
Just who did you get your parts from I have heard tell of knock off Aisin parts but have never seen any in person that I know of.
Good luck I hope you get this figured out.
If it were me I would pull the slave cylinder off Take it apart and have a look clean if needed
Run some clean brake fluid through the line with gravity .
It should flow free with the hot weather even more so
When you were bleeding when you opened the bleeder under pressure the fluid should shoot out.
Just who did you get your parts from I have heard tell of knock off Aisin parts but have never seen any in person that I know of.
Good luck I hope you get this figured out.
07-26-2013, 10:47 AM
#18
After messing with the clutch hydraulics for a week, I tore into the mechanicals of it.
Looks like the fork has some serious problems !!!
Anybody have a suggestion for a fast reliable place for OEM parts?
Looks like the fork has some serious problems !!!
Anybody have a suggestion for a fast reliable place for OEM parts?
07-27-2013, 06:04 PM
#20
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I am curious about the slave being maxed out for the bleeding. I replaced the MC, Slave and rubber line. Everything is adjusted. My clutch will work normal, but at times, say when i park the vehicle overnight I will get in and the pedal is loose and you have to push it all the way in to get it to allow me to shift. After a bit of driving it usually comes back to normal. I gravity bled everything, bled the MC properly, just a very odd situation. When the pedal is weak it seams to have about 1/2 inch or more of slop. When it is gets back to normal it is the standard 1/8 inch of play. For me it seems like i have air in the system somewhere and am thinking it may being in the slave. Anyone have this issue?
