Bleeding clutch system
#1
Bleeding clutch system
Yeah so I’m trying to bleed this stupid thing and I don’t know what I’m doing wrong. Got the hose from the bleeder to a cup w fluid in it, a friend pumps the clutch a few times then holds it, I open it for a sec and close it, he releases. We’ve done it maybe like 15 times. The hose is like half full from the bottom up and not going any higher. The pressure has gotten a little better but not much. What tf am I doing wrong??
#3
More detail needed. Why did you need to bleed the system? Any parts recently replaced? Is the hose from the bleeder screw tight on the bleeder screw? If not it could be drawing air back in between the bleeder screw & hose. Is the end of the hose on the "catch cup" BELOW the surface of the fluid? If not, again it could be drawing air back in. How fast is the clutch pedal being pumped? Should be slow & stead, not fast as you can. Are you making sure the fluid reservoir always has fluid in it when trying to bleed the system? Have you looked for nay leaks in the system? Have you checked the condition of the lines?
If you are trying to bleed the system because there is a lack of pressure in the system, but have not replaced any parts recently, and can't get it to bleed no matter what, you may have bad seals in your Clutch Master Cylinder, Clutch Slave Cylinder, or both. It's the seal that provide the "push" for the fluid & if they are shot or going bad, you will get little if any "push". Time for new parts or parts rebuild (new piston & seals).
If you have put on new parts recently (Clutch Master Cylinder and/or Clutch Slave Cylinder) double check that all your line fittings are snugged up properly to make sure no air is being drawn back through them. If a new Clutch Master Cylinder was recently installed, it could have air trapped in the bore, which will not compress enough to move the fluid. 2 options here. Fill the reservoir with fluid, have someone hold the pedal to the floor, & tap the Clutch Master Cylinder with a tool (screwdriver handle is good). This encourages air in the bore to work it's way out back into the reservoir to be replaced with fluid. Other way is to find something long enough to hold the clutch pedal to the floor (broomstick, length of 2x4 wood, etc.), put pedal to floor, wedge the "holder" in so it holds the pedal there, & leave it sit overnight. This will let air escape from the system & back up through the reservoir. Air in the system will naturally seek the highest point. I've done this before & it works 8 times out of 10.
Other than that, if all your seals & parts are working right, it can easily take more than 15 tries to get the clutch system bled out manually. Last time I replaced a master & slave cylinder on a truck it took about 80 cycles of pedal pumping. My friend's left leg is now bigger than their right one.
If you are trying to bleed the system because there is a lack of pressure in the system, but have not replaced any parts recently, and can't get it to bleed no matter what, you may have bad seals in your Clutch Master Cylinder, Clutch Slave Cylinder, or both. It's the seal that provide the "push" for the fluid & if they are shot or going bad, you will get little if any "push". Time for new parts or parts rebuild (new piston & seals).
If you have put on new parts recently (Clutch Master Cylinder and/or Clutch Slave Cylinder) double check that all your line fittings are snugged up properly to make sure no air is being drawn back through them. If a new Clutch Master Cylinder was recently installed, it could have air trapped in the bore, which will not compress enough to move the fluid. 2 options here. Fill the reservoir with fluid, have someone hold the pedal to the floor, & tap the Clutch Master Cylinder with a tool (screwdriver handle is good). This encourages air in the bore to work it's way out back into the reservoir to be replaced with fluid. Other way is to find something long enough to hold the clutch pedal to the floor (broomstick, length of 2x4 wood, etc.), put pedal to floor, wedge the "holder" in so it holds the pedal there, & leave it sit overnight. This will let air escape from the system & back up through the reservoir. Air in the system will naturally seek the highest point. I've done this before & it works 8 times out of 10.
Other than that, if all your seals & parts are working right, it can easily take more than 15 tries to get the clutch system bled out manually. Last time I replaced a master & slave cylinder on a truck it took about 80 cycles of pedal pumping. My friend's left leg is now bigger than their right one.
#4
+1 for checking the seals.
Clutch systems on these things only really have 3 parts to go wrong. Master/Slave cylinder and some lines connecting the two. Either one of the cylinders has failed, or you've got an air leak somewhere between the two.
In addition to what 13Swords said above, check the rubber boot on the master from the inside of the cabin. If you see any signs of oil seepage it's time for a new one.
Both parts are only about $15-30 bucks for some Aisin ones and are easy to swap out.
I spent over an hour trying to bleed my clutch after replacing the slave cylinder with a new one. Turned out the added resistance of a new slave cylinder was enough to blow out the seals in the (apparently barely) working master cylinder.
Clutch systems on these things only really have 3 parts to go wrong. Master/Slave cylinder and some lines connecting the two. Either one of the cylinders has failed, or you've got an air leak somewhere between the two.
In addition to what 13Swords said above, check the rubber boot on the master from the inside of the cabin. If you see any signs of oil seepage it's time for a new one.
Both parts are only about $15-30 bucks for some Aisin ones and are easy to swap out.
I spent over an hour trying to bleed my clutch after replacing the slave cylinder with a new one. Turned out the added resistance of a new slave cylinder was enough to blow out the seals in the (apparently barely) working master cylinder.
#5
Gravity bleed for 5 minutes or until the res is 1/2 full.
Adjust the bracket at the clutch pedal so that it has about 1/4" free play
Then do your normal process.
Open, push pedal slowly, close. Do not pump. I don't pump when doing brakes either.
After 5x you should be done. Should have pressure in round 2 or 3.
I have done this 20 times, always works.
If the process does not work, get the master and slave rebuild kits from Toyota.
Adjust the bracket at the clutch pedal so that it has about 1/4" free play
Then do your normal process.
Open, push pedal slowly, close. Do not pump. I don't pump when doing brakes either.
After 5x you should be done. Should have pressure in round 2 or 3.
I have done this 20 times, always works.
If the process does not work, get the master and slave rebuild kits from Toyota.
Last edited by ev13wt; Sep 26, 2019 at 04:34 AM.
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DupermanDave
86-95 Trucks & 4Runners
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