Clutch Slave Refresh

[Flyinace2000]

Update:

Clutch pedal is very low again.  A few days ago i notice the the banjo on the slave was slightly (very slightly) damp.  I dried it up, and snugged it a bit (maybe 1/8th of a turn on a wrench).  Besides re-bleeding what else should i check for?

-Will

[MiniDave]

You used a new slave cylinder, right?

Did you change the master too? If not, that's where I would go....once again, those parts are pretty cheap except for the wait and the shipping.

[Flyinace2000]

You used a new slave cylinder, right?

Did you change the master too? If not, that's where I would go....once again, those parts are pretty cheap except for the wait and the shipping.

Yup, new slave.  I just re-bleed the system. no bubbles. but pedal feels better.  To properly bleed do you need to bring in the adjustment screw so that the slave can be fully "compressed" by the return spring?  (I did it that way during install, but not just now).

[MiniDave]

That shouldn't be necessary, the bleed screw is at the top of the cylinder - I know you have to do that with BINIs, but I've never had to with our classics.

[Flyinace2000]

Rebled system last night. This morning back to not enough throw to disengage. I can force it into 1st or second but reverse just grinds gears.

Should I try readjusting the throw arm again? Time for a new or rebuilt master cylinder? New clutch itself?

[MiniDave]

It's not the adjustment, it was working fine before......the problem is the hydraulics...I'm betting on a master cylinder - but that's an easy bet as there is nothing left! Replace the short flex hose to the slave also if you didn't already....

[MPlayle]

I agree with Dave, it is still in the hydraulics.  If bleeding the system restores operation for a bit and it goes bad after siting overnight, air is still getting into the system somewhere.

The two things I can think of to try would be if the old slave cylinder was not leaking, try it again, otherwise look to the master cylinder as Dave indicates.

Not likely the flex line as it sounds like you went with the longer one-piece braided line from the master direct to the slave by your reference to "banjo bolt".

[Flyinace2000]

Yup, single flex line with banjos on both sides.only part left is the master cylinder. Is the hardest part disconnecting the master from the pedal?

[MiniDave]

Yes, getting the cotter pin out of the clevis is tough enough, but getting it and the clevis pin back is even more fun! Take the seat out and pad the crossmember to save your back......they make a simple tool to replace the clevis. A straight piece of metal about an inch wide with a slot in the top wide enough for the clevis and a piece of spring steel to hold tension on the head of the clevis.....for the cotter pin, a long pair of needle nose pliers works best.

[94touring]

Long needle nose makes the job fairly easy.  Your first time may prove to be frustrating however.

[Flyinace2000]

First time always sucks. Any benifits to getting the plastic vs metal master? Mine is currently metal.

[MiniDave]

Plastic ones won't rust and you can see both how much fluid is in there and how clean it is, other than that.....I doubt it unless you were going for original style.

[Flyinace2000]

Plastic ones won't rust and you can see both how much fluid is in there and how clean it is, other than that.....I doubt it unless you were going for original style.

I'm pretty sure my engine isn't original to the car, so not to concerned about "originality"

[Flyinace2000]

Here is the video of the movement.

https://goo.gl/photos/zVH9AxA64kv43qqXA

Clutch arm moves almost immediatly with putting weight on the pedal.  to the floor and hold it does not move.  the only other thing is the carpet, there is a pad and some carpet, thats the extra bit of movement you see when she stands on the pedal and that stuff compresses.

[MPlayle]

In the video, it looks almost as if the stop nut is just slightly to close and you are hitting it before the end of the arm travel.

As an experiment, back the stop nut off a measurable amount so that there is still a tiny amount of clearance when you push the clutch pedal all the way.

You may nee to remove the lever arm and be sure the knob end has not gotten bent.  On some of the other forums, there was a discussion a while back about soft lever arm metal allowing the knob to bend back if the stop nut hit before the end of pedal travel.  The leverage forces of the slave cylinder action were strong enough to bend the knob back.

Note also, some folks will say you can remove the stop nut completely and leave it off as it is not necessary.  I have had some Minis that had them and some that did not.

[Flyinace2000]

I had the same thought after I posted the video. I backed off both nuts and got another 1/4 of travel. I also removed some of the under carpet insulation for bit more pedal travel.

Works perfectly now.

[MiniDave]

You should not remove the stop nuts, they keep you from shoving so hard you eat the thrust washers.

The correct adjustment is 20 thou clearance at the stop nut (remove the spring and pull back on the arm)

Then set an 1/8th inch drill bit against the bell housing and run the nut up till it just touches the bit. Do check the clutch arm and see if the ball end is bent back like MPlayle says.....

[MPlayle]

I did not mean to imply that the big stop nuts should be discarded (as some on Mini Mania will proclaim).  I meant only to back them off a tad to verify whether they were in too close.

I do advocate proper adjustment as Dave indicates.  If the big stop nuts are present, then they need to be properly adjusted.

I only indicated that some of the Minis I have owned did not have them and others did.  If they were present, I made sure they were adjusted.  If they were missing, I did not replace them.  I know at least one without could not use them as the plunger did not have the threaded end for them.