Clutch master cylinder 1986 FJ

[TMadlem84]

So my clutch just went out all of a sudden on my 86 FJ.  I was riding & within 10-15 minutes I had zero clutch left.

I got it home.  I tried adding fluid & bleeding out the air; no luck

I got a rebuild kit for the master cylinder.  I put that in (double checked that it was installed right twice) & am still not getting pressure after bleeding.  If I squeeze the handle without the first output hose connect & my finger covering the output hole, I get pressure & fluid (enough pressure to cause the fluid to squirt out the sides.  With just that first rubber hose connected, I get nothing... very little pressure... barely any fluid.

I assumed the hose had a leak, so I plugged one end of the hose & blew through the other end & I was unable to blow/suck any air through the hose.

Any idea of what could be going on?  Do I need to tear the master cylinder apart again & triple check?  Since I'm getting fluid out the master cylinder I assume it's all correct... but why wouldn't it be pushing fluid out of the hose?

& it will push some fluid out of the hose... but I can't get all the air to bleed out so that there is pressure on the clutch lever...

[racerman_27410]

Have you taken the slave cylinder off to see if it's wet around the seal?

also to bleed the master you have to "tickle" the lever to "tease" the tiny bubbles out..... either that or strap the lever back and leave it overnight with the handlebars turned  so the master cylinder is up (bubbles rise)


Kookaloo!

[TMadlem84]

I did not take off the slave.  The bleeder screw will have fluid squirt out... but air keeps squirting out too (no matter how much I bleed it).

I will try to strap the handle down tonight & see what happens.

[SlowOldGuy]

99% of clutch lever problems are the slave cylinder.  1% are master cylinder problems.  You attacked the 1%, time to rebuild the slave. 

Strapping the handle only works when you have a tiny amount of air left stirred up and suspended in the fluid.  If you're still leaking air (which I bet the slave cylinder is doing), then you need to fix that.

And, like Frank said, the slower and easier you "burp" the air out of the master cylinder, the faster you will accomplish the bleeding.

DavidR.

[thuber3040]

harbor freight has the vacuum bleeder on sale for 18.00, makes all of it a lot easier

[TMadlem84]

But I disconnected the slave & still have very little pressure at end of the line... shouldn't I still have pressure on the line?

[racerman_27410]

But I disconnected the slave & still have very little pressure at end of the line... shouldn't I still have pressure on the line?

not with the air still in the master cylinder.... if you just barely bump the lever you will be able to tickle the tiny bubbles out... it can be very time consuming so you had better check that slave cylinder before wasting anymore time on bleeding the master.... like David said  99% of FJ clutch problems are the slalve cylinder not the master.

its only three bolts holding the slave on just take it off and have a look.... i bet your questions (and the need to order a slave rebuild kit) will be obvious after you do

once you get the slave back in good nick then you can worry about getting the system bled.

Kookaloo!

Frank

[FJ Flyer]

Check to see if you have the tell tale peeling paint on the black cover under the slave.

[TMadlem84]

No peeling under the slave...

I ordered a slave rebuild kit... Hopefully that'll get the job done

[FJmonkey]

I recently rebuilt my clutch MC (and Slave) and had a bitch of time to bleed it. Or so I thought. I used a syringe (Thanks George) and pulled fluid through till all the bubbles went away. But when I compressed the lever it seemed weak and pumped very little. After much cursing and taking a break, I engaged that small amount of gray matter between my ears and figured I assembled something wrong. I know I put the seal and internal plunger in correctly as I very carefully laid out the parts exactly as I removed them. So I removed the lever and flipped the external plunger rod around. That fixed it, not the 3 or 4 times of bleeding it before I was ready to chew through nails. That little rod reduces the travel enough (when in Bass Akwards) to feel like a horrible bleed job. I felt like a dolt  once I discovered my mistake in not stopping sooner to consider why the first or second attempt to bleed the system did not work at all. All is good now, I am smarter for the experience.   

[TMadlem84]

Update: 

I rebuilt master, rebuilt the slave, & used a vacuum bleeder tool... & I still have no pressure on the clutch.

I hooked up my brake master cylinder & it still has no pressure...

Any advice?

[Dan Filetti]

Long shot:  When you had the slave off, did you happen to pull the rod out?  If so, did the ball bearing go rolling out of the rod hole and go across the garage floor and get lost?  This would feel like no pressure I'm thinking.

Swinging in the dark.  It'll be solved sooner if you stay with it.

Dan

[TMadlem84]

My dad did pull the rod out.  I just spoke with him & he said he pulled the rod out real slowly because he didn't know hownlong it was & is positive nothing fell out of the hole.  He's a pretty good DIY mechanic... So I'd trust that he didn't just yank it out & sent parts flying...

[andyb]

Well, start with the basics.

Does the clutch lever engage the piston in the master cylinder, and move it measurably?
If you "tickle*" the clutch lever, pulling it in perhaps 1/2" at a time and releasing, do you get champagne bubbles showing up in the master resevoir?
Have you wiggled the lines that travel up from where the lines go near the fork area?
Have you chased the lines, feeling for wetness/leaks along the full length of the line?
Does the slave cylinder show any movement at all (unbolt it) when you pull at the lever?
Did the clutch work prior to this?  You said it "went out", did it just start slipping or did it feel almost like it went into neutral?
Have you pulled the clutch cover off (other side, if you prop the wheels on 2x4's and use the side stand oil shouldn't leak out when you take it off, incidentally) and looked at the movement of the clutch rod itself?
Did you replace the spring within the slave cylinder when you replaced the seals?

If it went to basically nothing extremely fast, I'd question a ruptured line possibly.
If it just started slipping up in the >6k range, I'd imagine that it's time to pull the clutch pack.
If the slave cylinder doesn't move when pulling the lever and you're unable to get the air out, I'd guess at a blown clutch line OR a lack of movement of the master's piston (jammed a little askew).

Etc, etc.  It's really not a very complicated system, and yet there's a whole boatload of things that can go wrong with it.

*I'm glad to see that someone else has noted that just barely actuating the clutch lever is the fastest way to bleed them.  Once the lever is depressed past a certain point, the holes that fluid flow through are blocked and pulling more does nothing to bleed things other than possibly dislodge bubbles stuck further down in the lines.

Answer those, and odds are very good that it'll make it much easier to diagnose.  It's difficult and frustrating to get all the air out of a clutch system (or brakes, just as icky) when you've had it utterly open, it takes a shitload of time and a big wad of patience.  Last time I was in my clutch actuation system, we counted fully 450 tiny pumps of the lever before we stopped seeing air.

[RichBaker]

Long shot:  When you had the slave off, did you happen to pull the rod out?  If so, did the ball bearing go rolling out of the rod hole and go across the garage floor and get lost?  This would feel like no pressure I'm thinking.

Swinging in the dark.  It'll be solved sooner if you stay with it.

Dan

In my experience, when the ball falls out, the slave cyl piston bottoms out against the case and the clutch lever will NOT move at all... as in, rock solid. That's what it was like when MY ball fell into the pan, anyways.....