Slave/Master Cylinder issues...

[Riolongo]

Okay, after receiving the slave rebuild kit from Randy I finally had a chance to install this weekend. When I removed the piston there was considerable grime and light rust. I removed the old seals and spent some time with a Dremel polishing the bore and outer piston areas, looks pretty good, no burrs so I installed new seals and reassembled. There was also considerable grime built up inside the cavity where the push rod is, I simply removed it and carried on with the rebuild, again not sure if this is normal or something I need to be concerned about.

When attempting to bleed I had zero pressure on my clutch lever, tried pumping lever numerous times with little effect, I did see the odd small air bubble surfacing inside the reservoir but that's it. Basically there is no difference from before I rebuilt the slave cylinder and now so I decided to remove the master cylinder guts and see if the piston/seals were in okay shape. They look okay but now that I have it apart I'm going to try and find a rebuild kit locally and at a minimum replace the seals.

Does this seem normal when performing this rebuild or should I have had some resistance immediately? Any and all suggestions are greatly appreciated.

Thanks,

Mike

[FJmonkey]

If you did not make changes the master then the problem remains with the slave. Bleeding can be a problem. The preferred choice seems to be the reverse method. Get a syringe from any local farm supply house, adapt it fit the bleed nipple (Yes I said nipple on this forum) and push the fluid of your choice up to the master.... Don't mix fluids, and watch the fluid level in the master to prevent an over flow and possibly piss paint destroying liquid on your FJ. If you recently rebuilt your master them fess up. I can help with a possible issue. What else can you tel us?

[movenon]

I use a little different method of bleeding the slave Cly.  It has a down side, but it is the way I do it...
Put towels under the master cylinder area .  (this is the down side, if you are not careful brake fluid will escape the reservoir)
Put some fluid in the reservoir, no need to top it up just about half way to start with.
With the slave not bolted up but the fluid line is hooked up.  Take your thumb or finger and gently press in on the slave piston collapsing it.  You will see air/fluid being pushed back into to master cylinder reservoir.  The smaller of the two holes.

If you push to rapidly or hard fluid will shoot up like old faithful (remember the towels ?).  Brake fluid is nasty on pant and ABS....

When you release the piston it will suck fluid into the slave cylinder.  Keep repeating this until you see no more air bubbles coming back into the reservoir.
Bolt the slave back on. Top off your fluid and see how it works.  A day or two later I do a standard bleed to check for any air in the system.

Potentially messy, yes,   quick , yes.  I is just the way I do it.  All the usual disclaimers.....
George

[Riolongo]

"If you did not make changes the master then the problem remains with the slave. Bleeding can be a problem. The preferred choice seems to be the reverse method. Get a syringe from any local farm supply house, adapt it fit the bleed nipple (Yes I said nipple on this forum) and push the fluid of your choice up to the master.... Don't mix fluids, and watch the fluid level in the master to prevent an over flow and possibly piss paint destroying liquid on your FJ. If you recently rebuilt your master them fess up. Definitely did not rebuild my master, however I removed it yesterday to inspect and from what I can see it looks fine. I can help with a possible issue. What else can you tel us?"

As I've mentioned everything was running okay, I had noticed a small amount of clear fluid under the bike a couple of times, checked reservoir and topped up once. After that I had zero pressure on the clutch lever and at that time I ordered the slave rebuild kit from Randy. I can try bleeding again as you suggested and see if that solves the problem, however I'll have to reinstall the master cylinder first, may try and find new seals locally.

[ribbert]

.......spent some time with a Dremel polishing the bore........
Mike

I would think this is most likely your problem.

.......so I decided to remove the master cylinder guts and see if the piston/seals were in okay shape.
Thanks,
Mike

And this may well be another problem. The cylinder bores are aluminium. M/C (and slave) seals "mate" to the bore and when you remove and re install them they no longer provide a good seal. As a general rule you never remove the seals unless you intend replacing them. Removing them for inspection and then refitting them is asking for trouble, Yes, you can get away with it sometimes, or for a while, but you have shortened it's remaining life at best.

Noel