Questions about Clutch

[ModisetteJ]

Hey all,

New engine is in, and everything works fine. We installed the slave clutch, bled the line, and the clutch was still having issues keeping pressure. It would take me 2-4 pumps to build up enough pressure to engage the clutch. There are no visible leaks, and the line is not corroded anywhere. The only thing I did notice is I felt like the clutch pedal was too far out, so I moved the stop bolt in that keeps the clutch pedal from backing all the way off enough to hold the pressure. My questions:

Is it possible that the clutch pedal can come so far backwards that it relieves all the built up pressure in the line, making it not engage the clutch?

Do you guys think that, now that I have the stop bolt in further than it was before, I'm going to wear out my throw-out bearing? It seems like when the pedal is all the way relaxed now, the clutch is disengaged fully because there still is about a 1/2 inch of play in the pedal before it starts to engage.

 

[Output Shaft]

If you have to pump the clutch pedal to get enough hydraulic pressure to push in the clutch, and it has already been bled, the clutch master cylinder or slave is dying. Clutch hydraulic components should all replaced at the same time. So if the master is bad, replace the slave too. They don't cost much. The reason to replace both is that they wear at about the same rate.

First clutch engagement on a FJ60 should begin at the beginning of the pedal stroke, after the pedal has been depressed only a little bit. This is different than some modern cars.

You can't wear out the throw out bearing. In the later model 60s, the T.O. bearing is constantly spinning and under slight pressure on the clutch springs. It lasts 300,000 miles.

When the clutch pedal is released, there should not be any pressure remaining in the hydraulic line.

 

[ModisetteJ]

How long should the cylinders last? I just replaced them both last year.

 

[LAMBCRUSHER]

if you had the system open, you may need to do a full bleed again. reset pedal height, bench bleed the master, attach the hard line and gravity bleed to the slave bleeder valve keeping the reservior full, then do several push the pedal down to the floor with a help as tho you were pressure bleeding the brakes, keeping the res full, and try again. they should last a long time, but if they went dry and got full of air, dust and rust, then it may take a full from scratch bleeding...

 

[3_puppies]

How long should the cylinders last? I just replaced them both last year.

if they were aftermarket it could be the life of them.

 

[GM60]

Does your slave cylinder push rod have a threaded adjustment?
I don't know about US spec 60's, but here in Oz the earlier 60's had the threaded slave push rod adjuster, and later ones were self adjusting at the slave cylinder.
If yours has the threaded push rod, it must be adjusted correctly. If there is too much clearance between the adjusting nut and the clutch fork, you would need to pump the pedal to get the clutch to disengage.
There is also an adjustment at the master cylinder push rod up under the dash.
With the pedal fully up, there needs to be a small clearance between the push rod and the master cylinder piston.

 

[Beachcomber Bernie]

Same symptoms after using Toyota master & slave rebuild kits.
Reused original cylinders and did full bleed.
First push goes to the floor.
Second push gives enough pressure to shift.
Wait 10 seconds and the cycle repeats.

I was very careful not to change any adjustments and reused slave piston rod.
No leaks and solid bleed.

Is the next step replacing the cylinders?
I noticed a little pitting during the build but didn't think it was enough to matter.

 

[Output Shaft]

The fluid is leaking past the piston seal at the pitting in the cylinder wall.

 

[Beachcomber Bernie]

Ok then. New cylinders it is.
Thanks for the reply OS!