12 replies to this topic

[Gibbon]

Tried to bleed the clutch to no avail. The slave cylinder has been serviced, new Goodridge braided flexible & new unions intalled.

Dismantled and the cleaned the master cylinder which was full of gunk, carefully cleaned the seals and the piston chamber (the 3 little holes in the bottom of the piston were blocked.... problem sorted methinks). Put it all back together, I then tested with my finger over the outlet & there was good pressure when pumping the piston by hand.

Reinstall it, fluid in, undo the slave bleed valve and pump the clutch pedal .... nothing happens. Liquid isn't being drawn into the piston!

Bugger!

Any ideas chaps?

Edited by Gibbon, 03 June 2007 - 03:44 PM.

[busa1999]

if you can unbolt the slave cylinder and position it above master cylinder then bleed the air out, make sure piston does not pop out
i had a similar problem with a motorcycle brake system and sorted it that way.
hope this helps
mark

[Gibbon]

The fluid isn't getting to the slave cylinder Mark!

I'd expected to hear the master cylinder drawing in the fluid (like the bakes) when I pump the pedal.... but nothing ???
The level in the master cylinder hasn't moved.

[busa1999]

you prob have an air lock, which is why it will be better if you can get the slave cylinder above master cylinder as the air will rise through the fluid, like i said i had a similar prob with motorcycle brakes and took complete system off bike and bled it upside down so to speak and it sorted it.
your other option may be an easy bleed with a one way valve
cheers mark

[Yipstink]

Tried to bleed the clutch to no avail. The slave cylinder has been serviced, new Goodridge braided flexible & new unions intalled.

Dismantled and the cleaned the master cylinder which was full of gunk, carefully cleaned the seals and the piston chamber (the 3 little holes in the bottom of the piston were blocked.... problem sorted methinks). Put it all back together, I then tested with my finger over the outlet & there was good pressure when pumping the piston by hand.

Reinstall it, fluid in, undo the slave bleed valve and pump the clutch pedal .... nothing happens. Liquid isn't being drawn into the piston!

Bugger!

Any ideas chaps?

Hi Gibboon

I think you will find that your problem is that after your master cylinder overhaul the system is empty and as appose to the brake system the clutch system doesn't have a anti return valve so basically you can pump the clutch pedal until yeh leg drops off,wife's left yeh and yeh kid aren't young any more!!!
So with a good quality syringe connected to the bleed nipple with a nice piece of rubber pipe push fluid up from the slave to the master cylinder until you have got all the air out, tighten nipple, & "Job's a good un"!
Boot down twin silencer!

Ted

[Bass Man]

Yipstink is right here, although it should come through eventually, when I replaced my M/c it probably took about 20mins of pumping with no resistance and no movement of the fluid using an easibleed, I thought the valve on the kit was faulty first. It eventually came through, watch the level though because once it starts flowing it drops very quickly.

[Gibbon]

Yipstink was right allright. Got the big syringe from my local syringe shop and squeeeeezed the bugger till my fingers dropped off. Clutch now works perfectly and Robert is my father's brother.

Many thanks for your help Yipstink/Ted/Wharrever. I owe you a drink or 3

[Yipstink]

Yipstink was right allright. Got the big syringe from my local syringe shop and squeeeeezed the bugger till my fingers dropped off. Clutch now works perfectly and Robert is my father's brother.

Many thanks for your help Yipstink/Ted/Wharrever. I owe you a drink or 3

Nice one Gibooon!

Do like a Happy Ending

[Gibbon]

NEARLY A HAPPY ENDING !!!
So.... the master cylinder is now working fine, but I noticed this morning that the Pivot Arm is no longer sitting correctly on the adjuster screw (it was before bleeding the system).

"Piston in the slave cylinder is sticking" I thought, so I took the slave off and the piston isn't sticking !!! Any ideas chaps ?
(photo shows the pivot arm with the slave removed and it's still a couple of mm from the adjuster screw)

 Pivot_Arm.jpg   61.08K   7 downloads

[dklawson]

I assume you are still running the return spring on the top of the arm. If you unbolt the slave cylinder will the arm move back closer to the stop?

You've confirmed that the piston in the slave is still working. However, perhaps there is something in the bottom of its bore. Perhaps somehow some big chunk of debris got in there through the lines and isn't letting the piston go all the way down.

You didn't mention rebuilding the slave when you worked on the master. If you worked on the slave, is there any chance you put the piston in "backwards"? I remember there being a dished top to the slave piston to seat the pushrod. If the piston's in backwards, the pushrod will appear "too long" and push the arm to the left as shown in your picture.

[Gibbon]

Hi Doug, thanks for your reply. The return spring makes no difference and the slave piston is in the right way round. The slave was serviced, there's no debris in it.

The slave had been removed in the photo.

I actioned the clutch after bleeding it last week... it moved in and out and seemed OK but I've only noticed today the gap to the adjuster screw. Forgot to mention earlier that I can move the pivot arm back and forwards about 5mm by hand ... is that normal ?

Edited by Gibbon, 16 June 2007 - 01:06 PM.

[dklawson]

Where is the 5mm of motion? It's not at all uncommon for the clevis pins to wear or for wear to occur in the components the clevis pins pass through. You may feel better if you pull the clevis pin out of the clutch cover so you can remove the clutch arm and inspect it. The arms were in the clevis pin holes and the ball end that goes inside the rod the throw-out bearing is on. There's also a chance that a chunk of dirt or debris found its way down into the clutch cover and is keeping the arm from retracting all the way.

I'm not sure I'd get too worked up about this. With the spring off, I'd go through the normal clutch adjustments suggested in Haynes and others. The standard is to set the gap between the arm and the stop bolt in your picture to a gap of about 0.020". I've been told that's not really too critical. The other adjustment is the travel of the rod the throw out bearing is on. From memory, you loosen the two big nuts on the end of the clutch cover and have an assistant push the clutch pedal in and hold it down. Meanwhile, you tighten the inner nut until it just contacts the clutch cover. After your helper releases the clutch pedal you turn that nut one (1) more flat "in" and then you secure it with the jam nut. I can't remember whether you're supposed to adjust the stop bolt before or after you adjust the throw-out travel but I'd think you adjust the throw-out first. Anyway, If the clutch is working and the throw-out bearing isn't dragging on the clutch all the time, don't worry about the change in arm position too much.

[Gibbon]

The 5mm motion is in the pivot arm... I can move it 5mm to the left, and then back again. Then it won't go any further to the right and stays in the position as shown in the photo.

Will be removing and inspecting the clevis pin assembly as soon as I've typed this!