Clutch question

[Parksy]

Hi all

When pushing the pedal down on the clutch, it feels as if it has air in the system. So I bled it and it felt the same. So I put a new line and slave cylinder in and ditched the damper line. While it definitely feels better, it still feels as if it has air in the system. So having alook under the car at the slave cylinder, it appears that the fork coming out of the bell housing has abit of extra movement. I don't really know how to explain it. I'm thinking what I've found is that when pushing the pedal down, it gets to half way, then finally engages the pressure plate, then the rest of the travel of the pedal engages the clutch so i can put it in gear. I've had the patrol for a little over a month and while its drive able, I'd much prefer the feel of a full pedal. Anyone got any ideas here?

Cheers

Andy

[Dales300exc]

Do you have a heap of free play at the pedal?

[Parksy]

No free play at the pedal. Had the wife in the patrol pushing the pedal up to the stiff point and the slave cylinder was moving as it should. I'm thinking either the rod coming out of the slave cylinder is too short, the fork is bent slightly, or there is something wrong with the pressure plate.

[pearcey]

Praksy if the shaft was short the piston would pop out of the cylinder
going by what you have said you may have a broken diaphragm in the pressure plate
You haven't stated if the clutch slips or not or if the clutch has been replaced.
Normally if the clutch is just warn out it will release right at the top of the pedal travel
if it has a broken diaphragm the pedal will feel soft then frim and release ta the bottom of the pedal travel
Also if its broken the diaphragm if you give it a bit of stick it will slip

[Parksy]

Thanks pearcey, clutch doesn't slip. But going by your description it sounds like a broken diaphragm. Any way to confirm this as definite?

[pearcey]

Not really mate spent 40 years in the industry and some times things can be totally wrong in the diagnosis
One thing I would do is to run the engine and with very light pressure on the clutch pedal see if you can feel any thrust bearing wobble
that is if the pedal slightly vibrates or pulsates. If the diaphragm is cracked the finger heights are normally uneven and sometimes you can feel it in the pedal. If it`s had a new clutch fitted it may be OK and just be the settings with in the pressure plate IE where the diaphragm rolls over the fulcrum ring.Different brands slightly different feel.

[Parksy]

Thanks pearcey, much appreciated. Will try and feel for any pedal feel, would it be worth trying to feel for something at the slave cylinder/fork?

Hopefully it's just had an aftermarket clutch fitted. It doesn't slip or show any signs of weakness.

[pearcey]

Try and find out if a clutch has been fitted. You could pull the fork boot back and see if the pressure plate is painted as genuine are not.
Most times if the diaphragm is cracked it will slip. Also is it a boosted clutch they can some times give a very light feel at the top of the pedal

[Parksy]

It is a boosted clutch. With the engine off, pushing the pedal down feels like I'm getting full pressure the entire way down but with the engine running, it's light for the first half. Will pull the boot off and see what I can find.

Cheers

[BigRAWesty]

It is a boosted clutch. With the engine off, pushing the pedal down feels like I'm getting full pressure the entire way down but with the engine running, it's light for the first half. Will pull the boot off and see what I can find.

Cheers

Before pulling things apart, check for leaks in the vacuum line. If your breaks are fine then I'd say it would be close to the master cylinder.

If you find the hose pop ot off while running and there should be a noticeable suction. Nothing to rip skin off but should hold to your finger easily..

Kallen Westbrook
Owner of
Westy's Accessories (http://www.nissanpatrol.com.au/forums/showthread.php?15134-Westy-s-Accessories.-A-small-back-yard-builder.)

[pearcey]

Andy looking at what you`ve said I think the clutch may be OK it just releases at the bottom of the stroke. The light feel at the top may not be anything to worry about

[Parksy]

Cheers

I'm hoping that is the case. The piston in the slave cylinder doesn't return all the way back in the cylinder, it sits at about the halfway point. When pushing the pedal I only have half the travel to engage the clutch, hence why I thought a longer rod would solve this and ectually push the piston back all the way when the pedal is released. Tried to make it slip, but I couldn't, so I suppose I just have to get used to the pedal feel.

Cheers

[pearcey]

Andy mate the piston does not return fully as when the clutch wears it it has got to return further in to the cylinderso we do not lengthen the push rod I know there are some adjustable push rods on certain vehicles but the factory engineers know what their doing so stick with the solid rod .You will find that as the clutch wears that the release height will change and it will gradually release higher this will take a long time.
all the best Pearcey

[mudski]

Try and find out if a clutch has been fitted. You could pull the fork boot back and see if the pressure plate is painted as genuine are not.
Most times if the diaphragm is cracked it will slip. Also is it a boosted clutch they can some times give a very light feel at the top of the pedal
Not entirely true that. I just replaced my GU clutch with a 4Terrain kit and the PP was unpainted... Anyway, if the clutch engages just off the floor, not much to worry about IMO. If it's gonna go, its gonna go. Pull the boot back wher ethe fork comes out and try to get some lube on the bearing carrier where it slides on the input shaft housing. Might just need a lube up.

[Gu01patrol]

I had a very similar problem and about 2 months later the dual mass flywheel let go, so I then converted to a solid flywheel and pressure plate conversion, if its anything like mine were I had to push the pedal almost to the floor to engage then I feel you could be in a similar boat
I also experienced a small vibration in the flywheel area while driving before the dual mass separated

I am not a mechanic this is what happened to mine

[Parksy]

Cheers guys. I will get some lube on things as soon as I get a chance. How easy is it to do this? There isn't much room but I suppose all I need is a thin stick or long screw driver with a little grease on the end?

I'm pretty sure the gq doesn't have a dual mass flywheel, so I'm sure I'm safe in that regards.

Cheers

Andy

[Gu01patrol]

Cheers guys. I will get some lube on things as soon as I get a chance. How easy is it to do this? There isn't much room but I suppose all I need is a thin stick or long screw driver with a little grease on the end?

I'm pretty sure the gq doesn't have a dual mass flywheel, so I'm sure I'm safe in that regards.

Cheers

Andy

Sorry M8 not knowing what you are driving I guess it was of me to assume you we're driving a gu as reference was made to a gu clutch so for my input yrs and a gq does not have a dual mass

[Parksy]

Not entirely true that. I just replaced my GU clutch with a 4Terrain kit and the PP was unpainted... Anyway, if the clutch engages just off the floor, not much to worry about IMO. If it's gonna go, its gonna go. Pull the boot back wher ethe fork comes out and try to get some lube on the bearing carrier where it slides on the input shaft housing. Might just need a lube up.

Great advice mudski! I pulled the boot back and gave the fork pivot point a lube up. I wasn't able to reach the bearing carrier shaft to lube it, if anyone here has done this successfully tell me how you've done it. But either way, just lubing the pivot point had made a vast difference to how the clutch feels. Funnily enough it almost feels as if I've regained the full clutch pedal.
Now that I think about it, when I mentioned that the slave cylinder piston rests at about the half way point, it's more at the 1/3 point. And even so, this shouldn't be the cause of the soft pedal because the piston isn't returning fully, I guess it's like an automatic adjustment mechanism. I'm thinking another clutch bleed and hopefully this will solve it. If not I might look at the master cylinder and try adjusting there. Hopefully this made sense...

Cheers

Andy

[mudski]

When the carrier is dry it will tend to stick to the input shaft housing. If you can use a long screw driver or what ever with some grease on it, and you get the grease on it, I bet it will feel much better. Something I should have done when I had the gearbox out of my GU is make a grease hose from the carrier to the bell housing. So I could grease it easily. All the prime movers use them and it would be real handy I reckon for the 4by's...