Clutch bleeding

skyhighZJ

skyhighZJ

Gov retirement < needs to live
Joined
May 31, 2012
Location
Aberdeen, NC.
Clutch master shit the bed in my ‘91 s10 (2.8 V6 T5 2wd). Replaced it tonight and can not get it to bleed. Had the wife get in and pump the pedal and hold while I cracked the bleeder on the slave. Got a bunch of air then solid fluid but still has no pedal pressure. Read all through the paper in the box and says nothing more than needing to gravity bleed and go. Did that and still no pedal. What am I missing?
 
On my YJ I had to remove the slave, let it hang straight down and depress the shaft/plunger a bajillion leventy times while I had my daughter watch all the air come out of the master and tell me when it stopped. It made a massive difference. I need to do it again cause I flipped the Jeep since then and got air in the system again. Now every time I get in it I have to pump the clutch a few times.
 
S10 and ranger clutches suck to bleed. If you have access to a mighty vac it'll help. I've had to push fluid up from the bleeder to the master before. I've also had luck putting a vacuum on the reservoir with a mighty vac while pumping the pedal to suck the air bubble out. Just be careful not to suck fluid out of the reservoir.

It helps if you side step the clutch too sometimes. When the pedal slams up it shakes the air loose too.

I've also heard of people taking the slave or master loose and tilting them when bleeding to get the air out but I've never had to do that.
 
I usually pull vacuum on the filled resi, with good results. Rarely do I have to bleed underneath doing it that way. When you let vacuum off, fluid fills where the vacuum pulls the air out. May need to do several times but it will get the air out. (Use this on f e series that don't have bleeders also)

I use the bleeder bottle so I don't need to worry about sucking up fluid into the vac pump.
 
Thanks gentlemen, after Uncle Sam releases me from servitude today I’ll give it a whirl. Tomorrow’s no good gotta jump ‘out da plane mon’ and sounds like tomorrow night till Thursday night it’s supposed to pour like 4” of rain. Gotta get my little hoopty back on the road!!
 
So I sucked and blowed and pumped and side stepped the pedal to knock loose air. Oh, and cussed for 4 hours tonight. Not a damn thing but a floppy, sloppy pedal. I’m pulling the master out tomorrow and going to exchange it. Everything was working to some degree prior and I previously replaced the slave and hose to get it on the road when I got it from Lizooki. So when it stopped working I figured the only thing left was the master so I swapped it out and here we are.
Question? Whatever way I am bleeding it I don’t see any real sizable bubbles but it seemed at different times I would see the fluid go down and then a small fountain back when the pedal would get pushed down then released: normal?
 
Yea that's normal. FYI don't step on the brake pedal on one of those old trucks with the big square master cylinder cap off or you'll be wiping brake fluid off the windshield, hood, and fenders.

As the piston passes the port in the reservoir, it cuts off the reservoir from the system, when you fully release the pedal and the port gets uncovered the fluid returning due to the clutch diaphragm springs (or brake calipers/ drum springs) pushes the fluid back. Then when the port uncovers old faithful erupts.

I won't say it's not a bad master because Lord knows the Chinese crap sucks, but it's likely just really stuborn. I've had rangers take half an afternoon to bleed and then you park them and when the customer comes to get it there's no pedal and you have to bleed it again!

One other technique to try, especially with new clutch or brake components is to open a bleeder first, press the pedal and hold it, then shut the bleeder then release. Instead of the normal pump a few times then hold down, then crack the bleeder method. It seems the first method moves more volume of fluid since it moves the fluid through the whole stroke instead of just compressing the air and that pushing fluid. The second method is better for finishing up, especially because frantic pumping on the pedal, like once you're frustrated, breaks the air bubble up into tiny bubbles which are even harder to get rid of.
 
Well I figured it out. So it’s a 2wd and this is very low to the ground so what did I do? Jacked the front up on jack stands. Finally jacked the rear end up so the truck was elevated but level and got a big burp out of the system. Apparently being at that angle was holding air in the slave. Holy shit what an ordeal. Thanks all for your replies!!
 
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