86 slave cylinder bleeding question
Thread Starter
Racer
Joined: Jul 2007
Posts: 462
Likes: 21
From: Kansas City Missouri
86 slave cylinder bleeding question
My car didn't have a problem in the world with the clutch until the motor was removed. At that time, a new throw out bearing was put in, because the old one was making a funny noise. (ok, so it had one problem). Now that it has been put back together, it has been bled 5 times, but there is still 5 inches of slack in the pedal and it won't really go in gear, even when the car is in motion. You can eventually get it in first with enough jockeying, but then the clutch immediately engages right off the floor. It seems the threads say new master and slave cylinders, but since it didn't seem to have any issues prior to the install of the throwout bearing, I wanted to run this past everybody to see if you thought it was still the master/slave or if it could be something else. There isn't some kind of linkage on these that can be adjusted, is there? What are the odds that there is still air in there?
Thanks
Thanks
Race Director
Joined: Dec 2003
Posts: 14,115
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From: Fremont Ca
2022 C4 of the Year Finalist - Modified
Race Director
Joined: Dec 2006
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for the self bleeding action to work the slave must be level. So throw a small level on it and jack the car as needed or park on the correct incline. hose comes in from the top so if you get the bore of the slave right the air will float up.
Thread Starter
Racer
Joined: Jul 2007
Posts: 462
Likes: 21
From: Kansas City Missouri
Is the pedal having free play a common sign of air in the line? Someone else has always done the bleeding, so I don't know if they ran it dry or not. Two different mechanics, so surely they knew what they were doing. I'll try the self bleeding method and see what I can accomplish myself.
Thread Starter
Racer
Joined: Jul 2007
Posts: 462
Likes: 21
From: Kansas City Missouri
Ok, opened the reservoir and ended up pumping it in two sets of 300. The first time, it seemed to help, so I dropped the hood for a good trial run, but by then it was grindi.g again in reverse. At first it went in ok. So I killed it and pumped another 300 times. Again, it seemed to work, but when I went to do a run, it again grinded in reverse. Am I making progress or is it an illusion? The oil was clear and not frothy and the levels remained the same. Thanks.
Melting Slicks
Joined: Jun 2013
Posts: 3,065
Likes: 39
Ok, opened the reservoir and ended up pumping it in two sets of 300. The first time, it seemed to help, so I dropped the hood for a good trial run, but by then it was grindi.g again in reverse. At first it went in ok. So I killed it and pumped another 300 times. Again, it seemed to work, but when I went to do a run, it again grinded in reverse. Am I making progress or is it an illusion? The oil was clear and not frothy and the levels remained the same. Thanks.
To get around this, you are supposed to put the car in first gear and then reverse. All without releasing the clutch. It shouldn't grind.
Good luck!
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Safety Car
Joined: Aug 2013
Posts: 4,424
Likes: 603
From: Minneapolis Mn
Bleeding the slave cylinder
After I got my 86 in August the slave cylinder went out.
I had my mechanic change out both the master and slave, he said he worked on bleeding it for something like 4 hours and still didn't get all the air out.
Well I found this video and tried it:
I tried it and I did get some air out, but it turned out I didn't get it all out, still didn't get the clutch to fully disengage.
Talked to a guy that used to be a GM mechanic and he gave me a suggestion - side slipping the clutch.
Pump the clutch up several times and hold the clutch pedal down for around 5 minutes (cap removed from the reservoir), then slide your foot off the clutch and let it pop up on it's own and it can pull some air out of it. I ended up doing this 2 or 3 times with a 15 minute or so delay between each attempt.
In the end I've had a very solid clutch that fully disengages the clutch without any problems and have not had a problem since.
It worked for me, hope that helps.
Paul
PS - this is assuming you have the right parts properly assembled. Worth double checking.
I had my mechanic change out both the master and slave, he said he worked on bleeding it for something like 4 hours and still didn't get all the air out.
Well I found this video and tried it:
I tried it and I did get some air out, but it turned out I didn't get it all out, still didn't get the clutch to fully disengage.
Talked to a guy that used to be a GM mechanic and he gave me a suggestion - side slipping the clutch.
Pump the clutch up several times and hold the clutch pedal down for around 5 minutes (cap removed from the reservoir), then slide your foot off the clutch and let it pop up on it's own and it can pull some air out of it. I ended up doing this 2 or 3 times with a 15 minute or so delay between each attempt.
In the end I've had a very solid clutch that fully disengages the clutch without any problems and have not had a problem since.
It worked for me, hope that helps.
Paul
PS - this is assuming you have the right parts properly assembled. Worth double checking.
Last edited by hcbph; Nov 24, 2013 at 08:52 AM.
Racer
Joined: Dec 2003
Posts: 277
Likes: 3
The best way to bleed this unit is to take it off the bell housing, tilt it to a 45 degree angle, in other words have the bleeder screw at the highest point. Bleed it just like a wheel cylinder, a couple of strokes of the pedel. You have to have the slave bleeder screw elevated so that you can remove the last bit of air.
Safety Car
Joined: Aug 2013
Posts: 4,424
Likes: 603
From: Minneapolis Mn
On air in the line, this is what I did. I couldn't raise the rear wheels at that time, so I blocked the front wheels with some chunks of 4x4 and plenty of space behind me 'just in case'. Started the engine with the transmission in neutral. Depressed the clutch and held it then after about 2 seconds tried shifting into reverse. If there was any grinding, there was still air in the line. When all the air was gone, no grinding into reverse with just depressing the clutch. That was my method to check. I then tried it on the street and it worked.
While working out the air, if my test failed, I'd pump the clutch pedal a half dozen times or so then tried reverse. If it ground initially but not when pumped up, that confirmed some air was still in the line.
Last edited by hcbph; Nov 25, 2013 at 10:23 AM.
Thread Starter
Racer
Joined: Jul 2007
Posts: 462
Likes: 21
From: Kansas City Missouri
I pumped it a bunch more times tonight and tried the 5 min hold side slip approach. It's definitely getting better than it was, but still hard to get in gear and grinds badly in reverse (even when going from first to reverse as suggested above). Why are these so painful? Master looks good. No visable leaks....haven't crawed under to check the Slave yet.
Safety Car
Joined: Aug 2013
Posts: 4,424
Likes: 603
From: Minneapolis Mn
Slave
That's got to be the main culprit. I figure if I ever have to do it again I'll change out the line for braided so the slave can be moved above the master to bleed that sucker properly.
Wouldn't you just love to make that engineer bleed a few hundred slave cylinders for punishment
