clutch/going in gear problem

Lor · Apr 16, 2007

Hi all,

I would like some tips on my problem. I have a master/slave cylinder put in. Now, I can't seem to shift into gear when the cruiser is moving. When the engine is off, I can felt pressure on the pedal. Shifting is good. But when the engine is running and start driving a few blocks, there seemed to be little pressure on the pedal. If I parked the cruiser and shut off the engine, I get the pressure back. What is going on? There's no sign of leaking fluid. Would like to get this thing back in the woods. Thanks.

wayne_fj40 · Apr 16, 2007

Sounds like you may just need to bleed it out

Lor · Apr 16, 2007

I already bleed the hell out of it. Like I said, when the engine is off, there's pressure. Some times when I just start the engine and press the pedal, I can feel less pressure. Bleed some more?

wayne_fj40 · Apr 16, 2007

Is this for a landcruiser?

Eric · Apr 16, 2007

Is the travel distance on the clys wrong? is it not fully disengaging?

GaryTJ · Apr 16, 2007

you didn't by chance put a return spring on it, did you?

Lor · Apr 16, 2007

Is this for a landcruiser?

yes. '78 fj40.

Is the travel distance on the clys wrong? is it not fully disengaging?

Not sure. I got the cyns from coolcruiser. The second question is yes, I think. When there's no pressure, I can't shift into gear. Some times I can pump a few times to build up pressure and be able to shift.

you didn't by chance put a return spring on it, did you?

Not sure what this is.

Eric · Apr 16, 2007

Pump to get pressure? that sounds like a leak or air in the system, bleed it more and check for leaks

Lor · Apr 16, 2007

Eric said:
Pump to get pressure? that sounds like a leak or air in the system, bleed it more and check for leaks

I will bleed some more, but no sign of leak. I got good pressure when the engine is off. Some times when I start the engine and press the pedal, it got softed -little pressure. I don't think the engine has anything to do with the system, is it?

Eric · Apr 16, 2007

sounds like bad parts, either miss matched or bad.

64FJ40 · Apr 16, 2007

I assume there are no leaks anywhere? Sounds like the master is leaking internally.

Engine running/not has nothing to do with the pedal pressure except if the throwout bearing is fubar'd, I could see the pulsing causing the leakdown to accelerate.

You really need to lay under there and watch the slave cylinder/throwout fork move while somebody pushes & holds the clutch pedal.

Sometimes returning stuff to CCOT sucks, but sometimes it's not as bad. I guess it all depends on who you talk to, so good luck.

Lor · Apr 17, 2007

64FJ40 said:
I assume there are no leaks anywhere? Sounds like the master is leaking internally.

Engine running/not has nothing to do with the pedal pressure except if the throwout bearing is fubar'd, I could see the pulsing causing the leakdown to accelerate.

You really need to lay under there and watch the slave cylinder/throwout fork move while somebody pushes & holds the clutch pedal.

Sometimes returning stuff to CCOT sucks, but sometimes it's not as bad. I guess it all depends on who you talk to, so good luck.

I was thinking that the reason I'm loosing pressure when the engine run is that fork vibrating causing the system to loose pressure. Now the question is, which one? I replaced the master and the slave. If this is the case, I suspect the slave since I did it last.

64FJ40 · Apr 17, 2007

Lor said:
I was thinking that the reason I'm loosing pressure when the engine run is that fork vibrating causing the system to loose pressure. Now the question is, which one? I replaced the master and the slave. If this is the case, I suspect the slave since I did it last.

If the slave leaks, fluid WILL leak out onto the ground (once it gets past the dust boot). This is the only failure mode for the slave.

The master, on the other hand, has two options. If the piston seal fails, it will lose pressure, but not leak anywhere. If the cylinder seal fails, it will leak fluid inside the cab near your left foot. Left unchecked, it will eat the paint off the driver's floorboard and cause (more) rust. This is especially prominent in cruisers with carpet because the leak is hidden.

Like I said before: lay underneath and watch the clutch fork move while someone else operates the pedal. This should give you a better idea of what's actually happening.

Not Jobless · Apr 17, 2007

Clutch cylinders, both slave and master are notorious for having to reverse bleed in order to get the air out.

Force fluid through the bleeder valve using a squeeze bottle and plastic tubing. This forces the air up the line and into the master which is where it wants to naturally collect anyway. Trying to bleed the system like brakes just forces the air down towards the slave temporarily and it just moves back and fourth in the line.

GaryTJ · Apr 17, 2007

sounds like no bench bleed before install. Now you need to take it back out and bench bleed, or vacuum the air out of it.

Lor · Apr 17, 2007

Jobless said:
Clutch cylinders, both slave and master are notorious for having to reverse bleed in order to get the air out.

Force fluid through the bleeder valve using a squeeze bottle and plastic tubing. This forces the air up the line and into the master which is where it wants to naturally collect anyway. Trying to bleed the system like brakes just forces the air down towards the slave temporarily and it just moves back and fourth in the line.

I think you're right. I had to do this on my Isuzu truck. I did the same to the cruiser, but I couldn't really force the fluid back to the master. I'll try again.

notstock · Apr 17, 2007

Push rod length being wrong will do this also. Don't remember if the LC rod length is adjustable or not. If it is too long the MC will never get any pressure.

GaryTJ · Apr 17, 2007

Lor said:
I think you're right. I had to do this on my Isuzu truck. I did the same to the cruiser, but I couldn't really force the fluid back to the master. I'll try again.

We do it the other way. Vacuum.

Make sure the master is most of the way empty and take something that will seal to the top of the master (old cap will do) put a small hole in it and take a handheld vacuum pump and suck it to 20" (dirty thought here...) and leave it at 20" or so for about 15 minutes.

It will retract the slave into the bore and draw all the fluid up into the master (hence having it about empty) I recomend having one of those resevoir bottles inline in case there is too much fluid, so you don't ruin the air pump.

the vacuum will also draw all the air bubbles out of the fluid.

take the cap back off. refill and pump the pedal back up and you are done.

(also works very well for power steering air purge)