New Clutch Dragging

[B0oStEr]

I've just fitted an r33 turbo g/box and heavy duty ceramic clutch in my r32.

I've bled the clutch to the best of my ability and I have a firm pedal.

The pedal is heavy and feels about right for 900kg but it gets progressively heavier all the way to the floor without the over centre easing of the effort I'm used to.

It is difficult to engage any gear from neutral and it crunches on gear changes.

The clutch takes up fast as soon as I lift my foot even 1mm.

It's obvious the pedal is not pushing the slave cylinder far enough for it to fully disengage the clutch and go over centre.

The master cylinder functioned without issue with the previous gearbox and clutch.

The slave cylinder is from ecr33 and has 3/4" bore and was reconditioned prior to fitting.

I've bled all three nipples but could there still be air in the dampener loop? I've heard these can be hard to bleed.

Does anyone know how far the slave cylinder is meant to push?

[Duncan]

Sometimes you have to adjust the takeup point for the clutch when you put a new or new type of clutch in, as it wears the take up point moves further towards the floor.

So jump upside down in the drivers footwell and have a look at the clutch pedal - there is a threaded metal rod that the pedal pushes into the slave cylinder. You need to disconnect the pedal from the rod and turn it to adjust the length

[The Dan]

If it is bled correctly and the master cylinder is adjusted correctly then you may need to get a longer push pin for the slave cylinder. remove the old one and get one that is approx 0.5cm longer....even a cut down bolt will do. Then all you have to do is fit the new longer pin in the slave and adjust the master push pin accordingly(no bleeding required to do this either).

[wrxhoon]

Duncan is on the money , i may add you dont need to disconnect the rod to ajust the pedal height .

Is the pedal now as heigh as the brake pedal ?

When you install a new clutch you dont have to bleed the hydrolics , you dont have to touch them at all .

[B0oStEr]

This is a gearbox conversion hence the new clutch and slave cylinder.

I had my mechanic (brother) check it out this morning.

Apparently it was already bled correctly.

I've got 14.5mm travel at the pushrod.

Is that factory spec.?

The pedal height was right but I lifted it 10mm so I can drive the car.

It's not a fix though, more like a bandaid

My brother reckons the problem might be in the new pressure plate assembly.

While it's important for the pushrod to be the correct length

a longer pushrod won't usually net more travel because it will only push the piston further back in the slave.

[wrxhoon]

If thats the case you will need either a bigger clutch master cilinder or a smaller slave cil or both .

A smaller slave will make the pedal heavier , a bigger master will make the pedal lighter ( with the same slave ).

If the system has air in it when you pump the pedal several times it will push the slave more , if there is no air it wont make any differance .

Was the clutch new or used ? If the clutch was new and you used the master and slave from the 33 that clutch belong to it should work .

[B0oStEr]

Should work properly but doesn't.

New 900kg pressure plate with cushion ceramic button clutchplate.

I only realised how heavy this clutch is when I drove my honda again. It felt like it had broken a clutch cable.

Slave and master diameters are stock, 3/4"slave 5/8"master, same as r33.

It feels a bit rough through the pedal. It sort of catches a couple of times as you push the pedal to the floor. It makes a twangy clunk noise.

Even though everything else has been double checked and working properly this pressureplate won't go over centre. It's only disengaging half way.

There must be something wrong with the geometry of the combination of component used to assemble it.

It's going back to the clutch place first thing Monday to see what they have to say.

BTW A bigger master cylinder is going to be heavier.

[wrxhoon]

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BTW A bigger master cylinder is going to be heavier.

<{POST_SNAPBACK}>

Yes you are right my mistake , smaller master will make it lighter and biggger slave will make it lighter . Big master + small slave makes pedal heavier .

It sounds like you may have a problem with the pressure plate .