Hydraulic clutch problems?
 

Hi all, I have a problem with my hydraulic clutch which i thought was a leaking slave cylinder so I bought a new one but this has not solved the issue!

When I push the pedal to blead the system (bleed pipe on the other end going into container full of fluid) the master level drops as it should and clutch fluid comes out the other end as it should.

I have put through approx 3 litres with no air coming out what so ever but the pedal remains limp and will not work the clutch.

I have double checked the 3 connections with no leaks and am at a loss as to the problem?

Does it matter in which position the clutch control arm is when bleeding?

The clutch was working before engine came out and has only covered 20k but the control arm can be moved anyway manually.

Has anyone got any ideas as to the problem or am I doing something wrong?

Cheers
Craig

Craig, are you pressing the pedal with the nipple open, then whilst holding the pedal down, closing the bleed nipple, then repeating the process?

No.............I take it that is the problem?

Wish I was not at work in an hour I would try that now will try tomorrow John and let you know cheers

Craig

I have just thought about this for a couple of minutes and now feel decidedly stupid.... I don't know how I expected the system to pressurize by just pumping through liquid :icon_rolleyes:

Hi Craig.

When you move the clutch arm, you should be able to move the clutch arm on the gearbox up to a certain point. then you will feel like you need super man to move any further. This is the clutch engaging.

And don't forget. Keep the master cylinder topped up.

Craig, I did mine as I described - seems to work okay.

Right this fracking clutch is now really starting to piss me off!

I have now spent about 25hrs on this thing including all day today and it's still not working.

I have had it to bits so many times and today managed to get a slight feel to the pedal for the first time enough to move the clutch fork about 4mm when pressed but not enough....

does anyone have any ideas??????????????

what I can say is that there is a new slave on there and the master cylinder when pedal pressed whilst bleeding will empty the fluid in three presses so it must be shifting enough fliud

Craig

Craig

Just a thought, as I have had this issue when bleeding brakes, is the car level, not trying to apear insulting but sometime the simplest things can help.

Is it worth contacting you local Honda dealer if there are any secrets they can offer.


Steve

Cheers Steve, no it's not insulting I am sure it is something very simple like that but just can't get it, yes car is level and I have tried unbolting the master cylinder and lowering it below lines to see if this makes a differance but it did not.

I'm not even sure why the clutch has got a bit firmer today and I can't help thinking that somewhere there is either an air pocket or a leak but no fluid is leaking from the 3 connectors

Hi Craig.

Been there done it with the Rover Clutch. I the Rover clutch are known to be barstewerds to bleed. Especially the 600 TI which I learned how to do it.

This is the way I did it.

Three people to start off with.

Top up reservoir fully. Check and top up during process when necessary.

Get assistant to sit in car.

Put clear plastic tube onto bleed nipple on slave cylinder and end into glass jar.

Open up bleed screw and ask assistant to depress clutch pedal fully ~ by hand is best at this stage ~ pedal may plop to floor quickly and stay there ~ that can be normal. Leave it there. Close bleed screw.

Ask assistant to raise clutch pedal fully and hold there.

Open slave bleed nipple.

Ask assistant to depress pedal fully and hold down.

Close bleed nipple.

Raise pedal and hold.

Open nipple.

Depress pedal.

Close nipple.

Repeat this process untill bubbleless fluid appears in tube/jar. May need to do this ten times ~ maybe less ~ depending how much air allowed into system when it ran dry.

Then open nipple one more time and push pedal to floor AND HOLD IT THERE!

Close nipple immediately with pedal still flat on floor.

Change of process now. Still under car, open slave cylinder bleed nipple and push in slave's push-rod as far as you can and hold it there. This will expell any air out of the SLAVE cylinder ~ lock nipple and relase push rod which should return in a second or so. You can push the push rod into the slave by hand easily with the nipple open. Don't forget to top up reservoir as this process will use quite a lot of fluid through the sytem.

Open nipple and push the push rod into slave as far as you can, hold it there and close nipple, repeat a couple more times observing clear fluid into tube ~ ideally no bubbles now. Check nipple firmly closed.

Then get a length of wood say 2 by 1" or better still a tube about 20" long ~ as used with small hydraulic jack handles works well.
No need for the assistant inside the car now except to observe the pedal ~ still on the floor. The next operation should return the clutch pedal to the fully raised position so that it stays there!

Place the wood or tube in such a way that you can use it to lever carefully and slowly the push rod into the slave cylinder ~ only this time with the bleed nipple still locked shut NOT open. As you do this, provided you have expelled all the air from the sytem as described above, you should hear the clutch pedal return to the fully up position WITHOUT assistance as your pushing fluid back up the system towards the master cylinder. This process usually will make a 'clunk' inside the car as it does so. If it does, you know you've sorted it and you can relax the leverage pressure on the slave push rod so that it returns.

Select neutral and start car. Depress clutch and select various gears to check operation.

Did that last weekend. My son since reports that the clutch and gear operation on his car is better than at any time before.... Sorted.

And a Rover 800 guy:

Get a jar, few metres of rubber tubing.
Make two holes in the lid for the rubber tubing.
One length of tube goes from caliper bleeder to jar.
Other length goes from vacuum outlet on the inlet manifold into the jar.

Start the engine and you've got a vacuum pump.
Open or close the lid or close the bleed nipple to control the fluid input/output.

Dont let the tube from inlet manifold dip into the brake fluid or it'll go into the engine, shouldn't cause any damage anyway, just clouds of white smoke as it gets burnt.

I used a coffee jar, drilled two holes etc, keep the cardboard bit from the lid or it won't seal.
5 mitres of clear 5 mill tubing from Focus, less than a fiver.
Needs to be a glass or metal jar or it'll just collapse before you generate enough vacuum to suck the fluid out.
I'm surprised how much vacuum a 2 litre car can generate actually.

You will get the odd splash of fluid up the vacuum pipe, as long as you don't let the fluid get to the same level as the vacuum pipe you wont have a problem.

Used less than 500 ml to bleed a Rover 800, I've now got almost a whole gallon of Dot4 sitting in the cupboard, looks like I'll be bleeding every car I can find to finish off what's left.

Hope this helps.

Hi John, thanks for your reply good post but unfortunately I had already done all of the above except push in the slave cylinder and I have done that tonight but no differance.............

My pedal is not actually soft about the same as my clutch pedal on my astra td and the clutch fork does move about 4mm but I am now 100% certain that I have covered all the possible probs so am at a loss what to do??

I can either rip it out and put cable in which would mean a new pedal box or I can get a mechanic to have a look but but I fear this would do no good!

I am sure this will pass but at the moment I feel like leaving the piece of shit well alone to rot.

Many thanks guys for the advice though it's appreciated

Craig

What system are you using?

He's using a honda master and slave.

Oh. Probably no help at all then. I was going to say that Rover have a valve of sort part way down the pipe. Don't know how important this is.

The really odd thing is that my identical setup (master and slave) was bled in a spare 5 minutes, and seems to work fine. :noidea:

Well I ordered a new master clutch cylinder the other day to see if this improves things, that will mean all new parts fitted now!!

I pick it up in the morning so hope to have it fitted tomorrow night

Craig

Last week before you posted this I did start to wonder about a restricted flow valve or a checked one way valve but alas apparently there is not on the honda

One brand new slave cylinder, master cylinder and all new o-rings later and..................no differance infact the fork moves less with the new master on than the old one!

Nothing left to try

Hi Craig.

I have no valve in my system.

OK things to try:

Make sure the clutch and lever are ok. You will have to get a measurement off one of the other honda guys of how much the slave lever moves to engage clutch. Then try it by hand. As it gets stiff (this is the clutch engaging) you might need help levering it further.

When you tried the above, what were the bubbles doing in the clear tube at the slave when the pedal was being pressed? Going towards the jar or back towards the master cylinder? I know the above is a long winded process with the dancing of feet and spanner at either end, but found that's the only way that works. Not tried the vac bleed but heard it's works great.

I wish I was closer otherwise I would give you a hand.

Craig,

There must be something, that all of us have overlooked.

If the system is hydraulically sound, and it has to be given new components, and no leaks, then it'd be handy if you could post pictures of your system from pedal to slave cylinder.

As for master cylinder stroke, the full travel of my clutch pedal translates to about 95 % of the master cylinder stroke. The Clutch starts to bite about 40% of the way up the pedal stroke. The action is quite digital, as the pedal is quite short (about 60% of the honda clutch pedal length at a guess).

John.

Right here goes, John the bubbles go towards the jar when pedal pressed!
some photos in order from front to back of car

Pic of reservoir and master cylinder
http://i157.photobucket.com/albums/t...y/DSC00574.jpg

Close up of master cylinder
http://i157.photobucket.com/albums/t...y/DSC00568.jpg

Pic of inside the car clevis and master piston
http://i157.photobucket.com/albums/t...y/DSC00571.jpg

pic of pedal in place
http://i157.photobucket.com/albums/t...y/DSC00580.jpg

exiting the rear bulk head
http://i157.photobucket.com/albums/t...y/DSC00582.jpg

entering the slave
http://i157.photobucket.com/albums/t...y/DSC00585.jpg

when pedal pressed equates to 100% piston travel