Clutch bleeding issues
Discussion
Hi guys. I'm beginning to think I'm an idiot here. Please confirm that I am by telling me what I'm doing wrong. 
I'm trying to bleed the clutch on my Ultima and no matter how long I work on it, I can't get any resistance on the clutch pedal to build up. Here's what I'm doing:
Pre-operation:
a- Attach a clear plastic tube to the clutch slave cylinder bleed screw.
b- Drop the other end of the tube in a small bottle with a bit of brake fluid in it.
Operation:
1- Top off the clutch fluid reservoir, then put the cap on and tighten.
2- Get in the car, pump the clutch pedal 4-5 times, then wedge a screwdriver between the pedal and the floor to keep the pedal depressed.
3- Go to the back of the car and open up the bleed screw 1/4 to 1/2 turn on the clutch slave cylinder for 5 seconds.
4- I see a few bubbles, then eventually no more bubbles, only brake fluid moving through the tube
5- Close the bleed screw
6- Back in the car, remove the screwdriver and release the clutch pedal.
7- go back to step 1.
After I've stopped seeing bubbles in the plastic tube, I've repeated the cycle another 5 times. Still no resistance on the pedal. What am I doing wrong? can there be a large air bubble stuck somewhere in the line? How can I fix it if pumping the pedal isn't doing it?
Thanks,
Eric
I'm trying to bleed the clutch on my Ultima and no matter how long I work on it, I can't get any resistance on the clutch pedal to build up. Here's what I'm doing:
Pre-operation:
a- Attach a clear plastic tube to the clutch slave cylinder bleed screw.
b- Drop the other end of the tube in a small bottle with a bit of brake fluid in it.
Operation:
1- Top off the clutch fluid reservoir, then put the cap on and tighten.
2- Get in the car, pump the clutch pedal 4-5 times, then wedge a screwdriver between the pedal and the floor to keep the pedal depressed.
3- Go to the back of the car and open up the bleed screw 1/4 to 1/2 turn on the clutch slave cylinder for 5 seconds.
4- I see a few bubbles, then eventually no more bubbles, only brake fluid moving through the tube
5- Close the bleed screw
6- Back in the car, remove the screwdriver and release the clutch pedal.
7- go back to step 1.
After I've stopped seeing bubbles in the plastic tube, I've repeated the cycle another 5 times. Still no resistance on the pedal. What am I doing wrong? can there be a large air bubble stuck somewhere in the line? How can I fix it if pumping the pedal isn't doing it?
Thanks,
Eric
Clutch slave cylinder orientation in the 911 has it up the other way, as the gearbox is rotated 180 degrees to get the engine at the back of the car.
To get the clutch bleed you may have to take the slave cylinder off, cant remember, have not built one yet.
Do a search through the forum it has come up before.
To get the clutch bleed you may have to take the slave cylinder off, cant remember, have not built one yet.
Do a search through the forum it has come up before.
Your best bet is to get an Ezee-bleed.
This uses air pressure from a spare wheel and a fluid reservoir to keep supplying fluid to the system. All you do is open the bleed valve and watch your clear plastic tube until no more bubbles are coming out.
The method you are currently using is flawed.
This is a two person job. When ready with all your pipes and glass jar open the bleed valve. Have your assistant press the pedal down and up 4 times steadily and keep it down on the last stroke. Close the bleed valve & check the fluid level in the master. Repeat this process until no bubbles are seen. The valve should be opened sufficiently that there is no back pressure. Any pressure will just make the bubbles smaller and more difficult to get out.
As has been said you may need to release the slave cylinder from its mounting and let it dangle on the pipe this way any trapped air will find its way out of the bleed valve.
Steve
This uses air pressure from a spare wheel and a fluid reservoir to keep supplying fluid to the system. All you do is open the bleed valve and watch your clear plastic tube until no more bubbles are coming out.
The method you are currently using is flawed.
This is a two person job. When ready with all your pipes and glass jar open the bleed valve. Have your assistant press the pedal down and up 4 times steadily and keep it down on the last stroke. Close the bleed valve & check the fluid level in the master. Repeat this process until no bubbles are seen. The valve should be opened sufficiently that there is no back pressure. Any pressure will just make the bubbles smaller and more difficult to get out.
As has been said you may need to release the slave cylinder from its mounting and let it dangle on the pipe this way any trapped air will find its way out of the bleed valve.
Steve
MHunter said:
Operation:
1- Top off the clutch fluid reservoir, then put the cap on and tighten.
2- Get in the car, pump the clutch pedal 4-5 times, then wedge a screwdriver between the pedal and the floor to keep the pedal depressed.
3- Go to the back of the car and open up the bleed screw 1/4 to 1/2 turn on the clutch slave cylinder for 5 seconds.
4- I see a few bubbles, then eventually no more bubbles, only brake fluid moving through the tube
5- Close the bleed screw
6- Back in the car, remove the screwdriver and release the clutch pedal.
7- go back to step 1.
I think you'll find that you'll get a lot more fluid through if you pump the pedal gently while the bleed screw is open, def better with two people to work it but seems to work ok for me, you'll only get about 3 pumps of the pedal before you need to refill the reservoir. 1- Top off the clutch fluid reservoir, then put the cap on and tighten.
2- Get in the car, pump the clutch pedal 4-5 times, then wedge a screwdriver between the pedal and the floor to keep the pedal depressed.
3- Go to the back of the car and open up the bleed screw 1/4 to 1/2 turn on the clutch slave cylinder for 5 seconds.
4- I see a few bubbles, then eventually no more bubbles, only brake fluid moving through the tube
5- Close the bleed screw
6- Back in the car, remove the screwdriver and release the clutch pedal.
7- go back to step 1.
Don't have an Ultima, but do have a G50'd 911.... A couple of notable points about bleeding the clutch.
Vacuum bleeders are better IME, but you will need to wrap the nipple in some PTFE tape to get the fluid out of the slave without drawing air through the bleed tube, but don't block the cross drilled hole with the tape. Nuff Sed.
When I do the clutch on the 911, and the system has been completely drained (as in engine out), I often have to drain the air out of the clutch master cylinder. I guess there must be a high spot there somewhere, that the air collects.
I dunno if the Ultima uses the same clutch master, but if it does I guess it would apply to you too.
If you need to do it, it will require doing before the slave. Just open the nut on the master with the pedal released, push the pedal down until the fluid begins to weep out. Close the nut, and release the pedal. Repeat two or three times to be sure, then bleed normally.
The other thing to watch is that on the 911 the reservoir, has three takeoffs for hydraulic fluid. Two for brakes, right in the bottom of the tank, and another half way up for the clutch. It's easy not to realise that you need to have the oil above halfway in the tank to avoid getting air into the system, where obviously you have to start again from the master cylinder.
Vacuum bleeders are better IME, but you will need to wrap the nipple in some PTFE tape to get the fluid out of the slave without drawing air through the bleed tube, but don't block the cross drilled hole with the tape. Nuff Sed.
When I do the clutch on the 911, and the system has been completely drained (as in engine out), I often have to drain the air out of the clutch master cylinder. I guess there must be a high spot there somewhere, that the air collects.
I dunno if the Ultima uses the same clutch master, but if it does I guess it would apply to you too.
If you need to do it, it will require doing before the slave. Just open the nut on the master with the pedal released, push the pedal down until the fluid begins to weep out. Close the nut, and release the pedal. Repeat two or three times to be sure, then bleed normally.
The other thing to watch is that on the 911 the reservoir, has three takeoffs for hydraulic fluid. Two for brakes, right in the bottom of the tank, and another half way up for the clutch. It's easy not to realise that you need to have the oil above halfway in the tank to avoid getting air into the system, where obviously you have to start again from the master cylinder.
Edited by dilbert on Friday 30th May 07:21
I agree with Dilbert above on wrapping the Might vac connection. Lots of air enters through there and makes it tough to know when you have a solid flow of fluid. Also, make absolutely sure the reservoir doesn't go dry when you're working the fluid through. If it does, you're starting over. You'll know you're there when you see the clutch (as seen through the hole in the bell housing) almost hit the flywheel. It is a pain getting this right, but try to be patient and eventually you'll get it.
Paul
Paul
It's funny, I was about to ask about "bench bleeding" the master cylinder, as the MityVac manual mentions it is necessary when installing a new master cylinder (whihc I guess is the case here). The Ultima doesn't have the same master cylinder as the 911s, our is a dedicated master with only 1 port that goes to the slave. I have already taped the bleed screw with Teflon tape to minimize air going in the system around the threads.
This weekend I think I will bleed the whole line, then start from scratch with bleeding the master cylinder first, then bleeding the slave, with the Mityvac pump. Hopefully it will work this time.
I didn't think it would be that difficult to bleed the clutch.
This weekend I think I will bleed the whole line, then start from scratch with bleeding the master cylinder first, then bleeding the slave, with the Mityvac pump. Hopefully it will work this time.
I didn't think it would be that difficult to bleed the clutch.
Steve_D said:
MHunter said:
I got myself a MityVac vacuum pump bleeding kit. I'll try it tomorrow, after I get some more brake fluid.
I don't like the vacuum type bleeders as they can draw air into the system either adding to the problem or just confusing the issue.Steve
I finally got the clutch bled using the mightvac vacuum pump. I had to remove it from the gearbox and tape upside down (actually the orientation it would have been if installed on a non-inverted gearbox) on the frame. Everything worked fairly well, until I decided to test the clutch pedal for resistance without reinstalling the slave cylinder securely in place...
Edited by MHunter on Monday 2nd June 02:27
Hmmm. That's the same slave as the 911. I don't think the upside downness of the slave ought to matter though, because the bleed nipple is on the end. The only way I can imagine the slave end being a problem would be if the engine were *above* the gearbox, with the flywheel horizontal.
I can sympathise with the slave popping out, but it really isn't rocket science, connect a pipe from the bleed nipple to a jar of fluid, fill the reservoir with dot5, pump 3 times [use a stick to pump the pedal if necessary], refill with brake fluid.... repeat until no more bubbles come through, tighten the bleed valve. You can use kits but you do not need to, it's simple, honestly, but don't forget the slave.
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